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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 Kodiak C-Series (Conventional) C4/C5 🢒 Power and Signal Distribution 🢒 Wiring Systems and Power Management 🢒 Ignition Relay Diagnosis

Ignition Relay Diagnosis Ignition A

Circuit Description

The ignition A relay is normally an open relay. The relay armature is held in the open position by spring tension. When the ignition switch is turned to the run or start position, current will flow through the relay coil. A wire connected to the other end of the relay coil completes the path to ground. The electromagnetic field created by the relay coil overcomes the spring tension and moves the armature allowing the relay contacts to close. The closed relay contacts allow current to flow from the battery tot he following fuses:

    • The ENG 1 fuse
    • The ENG 4 fuse

When the ignition switch is turned to the OFF position, the electromagnetic field collapses. This action allows the spring tension to move the armature away from the relay contacts, which interrupts current flow tot he fuses.

If the ignition A relay fails to close, the engine will crank and run. The class 2 communications will be available with the use of a scan tool. The ignition A relay table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test.

Step

Action

Yes

No

Schematic Reference: Power Distribution Schematics or Ground Distribution Schematics and Engine Controls Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn ON the ignition, with the engine OFF.
  2. Remove the underhood fuse block cover.
  3. Probe both test points of the 10-amp ENG 1 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on both test points of the fuse?

Go to Step 3

Go to Step 12

3

  1. Turn OFF the ignition.
  2. Probe both test points of the 10-amp ENG 1 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on either test point of the fuse?

Go to Step 4

Go to Step 61

4

  1. Turn OFF the ignition.
  2. Remove the ignition A relay from the underhood fuse block with the J 43244 Relay Puller Pliers . Refer to Relay Replacement.

    3. Caution: Refer to Test Probe Caution in the Preface section.

  3. Probe the ignition 1 voltage circuit of the ignition A relay at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 8

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Remove the following fuses from the underhood fuse block:
    3. • The ENG 1 fuse
    • The ENG 4 fuse
  3. Probe the above fuse terminals in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate at any of the fuse terminals?

Go to Step 6

Go to Step 58

6

  1. Turn OFF the ignition.
  2. Disconnect the ignition A relay load circuit from the bus bar that leads to the 10-amp ENG 1 and the 10-amp ENG 4 fuse in the underhood fuse block.
  3. Probe the ignition A relay load circuit at the underhood fuse block, relay connector location, with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 36

Go to Step 7

7

Test the ignition A relay load circuit bus bar between the 10-amp ENG 1 and the 10-amp ENG 4 fuse in the underhood fuse block for a short to battery positive voltage. Refer to Circuit Testing.

Did you find a condition?

Go to Step 37

Go to Diagnostic Trouble Code (DTC) List - Vehicle

8
  1. Turn OFF the ignition.
  2. Disconnect the ignition 1 voltage circuit for the ignition A relay at the instrument panel (I/P) fuse block.
  3. Probe the ignition 1 voltage circuit for the ignition A relay at the relay connector location of the underhood fuse block with a test lamp connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors .

Does the test lamp illuminate?

Go to Step 38

Go to Step 9

9
  1. Turn OFF the ignition.
  2. Disconnect the ignition switch electrical connector that contains the ignition 1 voltage circuit for the ignition A relay.
  3. Probe the ignition 1 voltage circuit at the ignition switch electrical connector, vehicle harness side, with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 10

Go to Step 11

10
  1. Disconnect the I/P fuse block electrical connector that contains the ignition 1 voltage circuit from the ignition switch.
  2. Test the ignition 1 voltage bus bar circuit in the I/P fuse block for a short to battery positive voltage. Refer to Circuit Testing.

Did you find a condition?

Go to Step 39

Go to Step 40

11
  1. Turn OFF the ignition.
  2. Connect a 20-amp fused jumper wire from the battery positive voltage terminal on the vehicle harness side of the ignition switch electrical connector to the corresponding battery positive voltage terminal on the ignition switch. Refer to Using Fused Jumper Wires.
  3. Probe the ignition 1 voltage terminal at the ignition switch with a test lamp connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 59

Go to Step 58

12
  1. Turn OFF the ignition.
  2. Probe both test points of the 50-amp ENGINE fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on both test points of the fuse?

Go to Step 18

Go to Step 13

13

Does the test lamp illuminate on one test point of the 50-amp ENGINE fuse?

Go to Step 14

Go to Step 17

14
  1. Turn OFF the ignition.
  2. Remove the ignition A relay from the underhood fuse block with the J 43244 Pliers . Refer to Relay Replacement.

    3. Caution: Refer to Test Probe Caution in the Preface section.

  3. Probe the battery positive voltage circuit for the ignition A relay at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 41

Go to Step 15

15
  1. Turn OFF the ignition.
  2. Probe the load circuit of the ignition A relay at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 16

Go to Step 59

16

Test the ignition A relay load circuit between the load circuit terminal in the underhood fuse block and the 10-amp ENG 1 fuse for a short to ground. Refer to Circuit Testing.

Did you find a condition?

Go to Step 42

Go to Step 43

17
  1. Turn OFF the ignition.
  2. Probe the mounting stud for the battery positive cable at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate?

Go to Step 44

Go to Diagnostic Trouble Code (DTC) List - Vehicle

18
  1. Turn ON the ignition, with the engine OFF.
  2. Probe both test points of the 15-amp powertrain control module (PCM) 1 fuse in the I/P fuse block with a test lamp connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on both test points of the fuse?

Go to Step 30

Go to Step 19

19

Does the test lamp illuminate on one test point of the 15-amp PCM 1 fuse?

Go to Step 20

Go to Step 21

20
  1. Turn OFF the ignition.
  2. Remove the ignition A relay from the underhood fuse block with the J 43244 Pliers . Refer to Relay Replacement.

    3. Caution: Refer to Test Probe Caution in the Preface section.

  3. Probe the ignition 1 voltage circuit of the ignition A relay at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 45

Go to Step 58

21
  1. Turn OFF the ignition.
  2. Probe both test points of the 40-amp IGN 1 fuse in the MaxiFuse block assembly with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on both test points of the fuse?

Go to Step 26

Go to Step 22

22

Does the test lamp illuminate on one test point of the 40-amp IGN 1 fuse?

Go to Step 23

Go to Step 29

23
  1. Turn OFF the ignition.
  2. Disconnect the ignition switch electrical connector.
  3. Probe the battery positive voltage circuit from the 40-amp IGN 1 fuse at the ignition switch electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors .

Does the test lamp illuminate?

Go to Step 46

Go to Step 24

24
  1. Turn OFF the ignition.
  2. Remove the 15-amp PCM 1 fuse from the I/P fuse block.
  3. Disconnect the ignition 1 voltage circuit from the I/P fuse block.
  4. Probe the ignition 1 voltage circuit at the ignition switch electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 47

Go to Step 25

25

Test the ignition 1 voltage bus bar circuit of the I/P fuse block from the ignition switch to the following fuses for a short to ground:

    • The PCM 1 fuse
    • The GAUGES fuse
    • The SIR fuse
    • The TURN B/U fuse
        Refer to Circuit Testing.

Did you find a condition?

Go to Step 48

Go to Step 59

26
  1. Turn OFF the ignition.
  2. Probe the battery positive voltage circuit at the ignition switch electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 27

Go to Step 49

27
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit at the ignition switch electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 28

Go to Step 59

28
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit for the 15-amp PCM 1 fuse at the I/P fuse block electrical connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 50

Go to Step 51

29
  1. Turn OFF the ignition.
  2. Probe the mounting stud for the battery positive cable at the MaxiFuse block assembly with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate?

Go to Step 52

Go to Diagnostic Trouble Code (DTC) List - Vehicle

30
  1. Turn OFF the ignition.
  2. Remove the ignition A relay from the underhood fuse block with the J 43244 Pliers . Refer to Relay Replacement.

    3. Caution: Refer to Test Probe Caution in the Preface section.

  3. Probe the battery positive voltage circuit for the ignition A relay at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 31

Go to Step 53

31
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit of the ignition A relay at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 32

Go to Step 54

32
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the coil ground circuit of the ignition A relay at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 33

Go to Step 55

33
  1. Turn OFF the ignition.
  2. Jumper the ignition A relay battery positive voltage circuit and the ignition A relay load circuit together at the underhood fuse block with a 20-amp fused jumper. Refer to Using Fused Jumper Wires.
  3. Probe the following fuses with a test lamp that is connected to a good ground:
    4. • The ENG 1 fuse
    • The ENG 4 fuse

Does the test lamp illuminate on at least one test point of each fuse?

Go to Step 35

Go to Step 34

34

Test the ignition A relay load bus bar circuit to the 10-amp ENG 1 fuse and the 10-amp ENG 4 fuse in the underhood fuse block for a high resistance or an open.

Did you find a condition?

Go to Step 57

Go to Step 56

35

Test for an intermittent and for a poor connection at the underhood fuse block, ignition A relay connector location. Refer to Testing for Intermittent Conditions and Poor Connections.

Did you find a condition?

Go to Step 60

Go to Step 58

36

Repair the short to battery positive voltage in the relay load circuit between the ignition A relay and the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

37

Repair the short to battery positive voltage in the ignition A relay load bus bar circuit to the 10-amp ENG 1 fuse and the 10-amp ENG 4 fuse of the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

38

Repair the short to battery positive voltage in the ignition 1 voltage circuit between the I/P fuse block and the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

39

Repair the short to battery positive voltage in the ignition 1 voltage bus bar of the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

40

Repair the short to battery positive voltage in the ignition 1 voltage circuit between the ignition switch and the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

41

Repair the short to ground in the battery positive voltage circuit between the 50-amp ENGINE fuse and the ignition A relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

42

Repair the short to ground in the ignition A relay load circuit to the 10-amp ENG 1 fuse. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

43

Repair the short to ground in the ignition A relay load circuit to the 10-amp ENG 4 fuse. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

44

Repair the high resistance or an open in the battery positive voltage bus bar circuit tot he 50-amp ENGINE fuse in the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

45

Repair the short to ground in the ignition 1 voltage circuit between the 15-amp PCM 1 fuse and the ignition A relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

46

Repair the short to ground in the battery positive voltage circuit between the 40-amp IGN 1 fuse and the ignition switch. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

47

Repair the short to ground in the ignition 1 voltage circuit between the 15-amp PCM 1 fuse and the ignition switch. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

48

Repair the short to ground in the ignition 1 voltage bus bar circuit of the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

49

Repair the high resistance or an open in the battery positive voltage circuit to the ignition switch. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

50

Repair the high resistance or an open in the ignition 1 voltage bus bar circuit to the 15-amp PCM 1 fuse of the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

51

Repair the high resistance or an open in the ignition 1 voltage circuit between the ignition switch and the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

52

Repair the high resistance or an open in the battery positive voltage bus bar circuit to the 40-amp IGN 1 fuse of the MaxiFuse block assembly. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

53

Repair the high resistance or an open in battery positive voltage circuit between the 50-amp ENGINE fuse and the ignition A relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

54

Repair the high resistance or an open in the ignition 1 voltage circuit between the 15-amp PCM 1 fuse and the ignition A relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

55

Repair the high resistance or an open in the coil ground circuit of the ignition A relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

56

Repair the high resistance or an open in the relay load circuit between the ignition A relay and the 10-amp ENG 1 fuse. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

57

Repair the high resistance or an open in the ignition A relay load bus bar circuit of the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

58

Replace the ignition A relay. Refer to Relay Replacement.

Did you complete the replacement?

Go to Step 61

--

59

Replace the ignition switch.

Did you complete the replacement?

Go to Step 61

--

60

Replace the ignition A relay wire terminals at the underhood fuse block. Refer to Repairing Connector Terminals.

Did you complete the replacement?

Go to Step 61

--

61
  1. Replace any open fuses.
  2. Turn OFF the ignition for 30 seconds.
  3. Attempt to start the engine.

Does the engine start and run?

Go to Step 62

Go to Engine Cranks But Does Not Run

62
  1. Clear the DTCs with a scan tool.
  2. Operate the vehicle for 5 minutes.

Does a DTC set during this ignition cycle?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK

Ignition Relay Diagnosis Ignition B

Circuit Description

The ignition B relay is normally an open relay. The relay armature is held in the open position by spring tension. When the ignition switch is turned on to the run or start position, current will flow through the relay coil. A wire connected to the other end of the relay coil completes the path to ground. The electromagnetic field created by the relay coil overcomes the spring tension and moves the armature allowing the relay contacts to close. The closed relay contacts allow current to flow from the battery to the following fuses:

    • The ENG 2 fuse
    • The ENG 3 fuse

When the ignition switch is turned to the OFF position, the electromagnetic field collapses. This action allows the spring tension to move the armature away from the relay contacts, which interrupts current flow to the fuses.

If the ignition B relay fails to close, the engine will crank but does not run. The class 2 communications will be available with the use of a scan tool.

The ignition B relay table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test.

Step

Action

Yes

No

Schematic Reference: Power Distribution Schematics and Ground Distribution Schematics , Engine Controls Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn ON the ignition, with the engine OFF.
  2. Remove the underhood fuse block cover.
  3. Probe both test points of the 15-amp ENG 2 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on both test points of the fuse?

Go to Step 3

Go to Step 12

3

  1. Turn OFF the ignition.
  2. Probe both test points of the 15-amp ENG 2 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on either test point of the fuse?

Go to Step 4

Go to Step 61

4

  1. Turn OFF the ignition.
  2. Remove the ignition B relay from the underhood fuse block with the J 43244 Relay Puller Pliers . Refer to Relay Replacement.

    3. Caution: Refer to Test Probe Caution in the Preface section.

  3. Probe the ignition 1 voltage circuit of the ignition B relay at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 8

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Remove the following fuses from the underhood fuse block:
    3. • The ENG 2 fuse
    • The ENG 3 fuse
  3. Probe the above fuse terminals in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate at any of the fuse terminals?

Go to Step 6

Go to Step 58

6

  1. Turn OFF the ignition.
  2. Disconnect the ignition B relay load circuit from the bus bar that leads to the 15-amp ENG 2 and the 15-amp ENG 3 fuse in the underhood fuse block.
  3. Probe the ignition B relay load circuit at the underhood fuse block, relay connector location with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 36

Go to Step 7

7

Test the ignition B relay load circuit bus bar between the 15-amp ENG 2 and the 15-amp ENG 3 fuse in the underhood fuse block for a short to battery positive voltage. Refer to Circuit Testing.

Did you find a condition

Go to Step 37

Go to Diagnostic Trouble Code (DTC) List - Vehicle

8
  1. Turn OFF the ignition.
  2. Disconnect the ignition 1 voltage circuit for the ignition B relay at the instrument panel (I/P) fuse block.
  3. Probe the ignition 1 voltage circuit for the ignition B relay at the relay connector location of the underhood fuse block with a test lamp connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors .

Does the test lamp illuminate?

Go to Step 38

Go to Step 9

9
  1. Turn OFF the ignition.
  2. Disconnect the ignition switch electrical connector that contains the ignition 1 voltage circuit for the ignition B relay.
  3. Probe the ignition 1 voltage circuit at the ignition switch electrical connector, vehicle harness side, with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 10

Go to Step 11

10
  1. Disconnect the I/P fuse block electrical connector that contains the ignition 1 voltage circuit from the ignition switch.
  2. Test the ignition 1 voltage bus bar circuit in the I/P fuse block for a short to battery positive voltage. Refer to Circuit Testing.

Did you find a condition?

Go to Step 39

Go to Step 40

11
  1. Turn OFF the ignition.
  2. Connect a 20-amp fused jumper wire from the battery positive voltage terminal on the vehicle harness side of the ignition switch electrical connector to the corresponding battery positive voltage terminal on the ignition switch. Refer to Using Fused Jumper Wires.
  3. Probe the ignition 1 voltage terminal at the ignition switch with a test lamp connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 59

Go to Step 58

12
  1. Turn OFF the ignition.
  2. Probe both test points of the 50-amp ENGINE fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on both test points of the fuse?

Go to Step 18

Go to Step 13

13

Does the test lamp illuminate on one test point of the 50-amp ENGINE fuse?

Go to Step 14

Go to Step 17

14
  1. Turn OFF the ignition.
  2. Remove the ignition B relay from the underhood fuse block with the J 43244 Pliers . Refer to Relay Replacement.

    3. Caution: Refer to Test Probe Caution in the Preface section.

  3. Probe the battery positive voltage circuit for the ignition B relay at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 41

Go to Step 15

15
  1. Turn OFF the ignition.
  2. Probe the load circuit of the ignition B relay at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 16

Go to Step 59

16

Test the ignition B relay load circuit between the load circuit terminal in the underhood fuse block and the 15-amp ENG 2 fuse for a short to ground. Refer to Circuit Testing.

Did you find a condition?

Go to Step 42

Go to Step 43

17
  1. Turn OFF the ignition.
  2. Probe the mounting stud for the battery positive cable at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate?

Go to Step 44

Go to Diagnostic Trouble Code (DTC) List - Vehicle

18
  1. Turn ON the ignition, with the engine OFF.
  2. Probe both test points of the 15-amp powertrain control module (PCM) 1 fuse in the I/P fuse block with a test lamp connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on both test points of the fuse?

Go to Step 30

Go to Step 19

19

Does the test lamp illuminate on one test point of the 15-amp PCM 1 fuse?

Go to Step 20

Go to Step 21

20
  1. Turn OFF the ignition.
  2. Remove the ignition B relay from the underhood fuse block with the J 43244 Pliers . Refer to Relay Replacement.

    3. Caution: Refer to Test Probe Caution in the Preface section.

  3. Probe the ignition 1 voltage circuit of the ignition B relay at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 45

Go to Step 58

21
  1. Turn OFF the ignition.
  2. Probe both test points of the 40-amp IGN 1 fuse in the MaxiFuse block assembly with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate on both test points of the fuse?

Go to Step 26

Go to Step 22

22

Does the test lamp illuminate on one test point of the 40-amp IGN 1 fuse?

Go to Step 23

Go to Step 29

23
  1. Turn OFF the ignition.
  2. Disconnect the ignition switch electrical connector.
  3. Probe the battery positive voltage circuit from the 40-amp IGN 1 fuse at the ignition switch electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors .

Does the test lamp illuminate?

Go to Step 46

Go to Step 24

24
  1. Turn OFF the ignition.
  2. Remove the 15-amp PCM 1 fuse from the I/P fuse block.
  3. Disconnect the ignition 1 voltage circuit from the I/P fuse block.
  4. Probe the ignition 1 voltage circuit at the ignition switch electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 47

Go to Step 25

25

Test the ignition 1 voltage bus bar circuit of the I/P fuse block from the ignition switch to the following fuses for a short to ground:

    • The PCM 1 fuse
    • The GAUGES fuse
    • The SIR fuse
    • The TURN B/U fuse
        Refer to Circuit Testing.

Did you find a condition?

Go to Step 48

Go to Step 59

26
  1. Turn OFF the ignition.
  2. Probe the battery positive voltage circuit at the ignition switch electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 27

Go to Step 49

27
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit at the ignition switch electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 28

Go to Step 59

28
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit for the 15-amp PCM 1 fuse at the I/P fuse block electrical connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 50

Go to Step 51

29
  1. Turn OFF the ignition.
  2. Probe the mounting stud for the battery positive cable at the MaxiFuse block assembly with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp.

Does the test lamp illuminate?

Go to Step 52

Go to Diagnostic Trouble Code (DTC) List - Vehicle

30
  1. Turn OFF the ignition.
  2. Remove the ignition B relay from the underhood fuse block with the J 43244 Pliers . Refer to Relay Replacement.

    3. Caution: Refer to Test Probe Caution in the Preface section.

  3. Probe the battery positive voltage circuit for the ignition B relay at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 31

Go to Step 53

31
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit of the ignition B relay at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 32

Go to Step 54

32
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the coil ground circuit of the ignition B relay at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors.

Does the test lamp illuminate?

Go to Step 33

Go to Step 55

33
  1. Turn OFF the ignition.
  2. Jumper the ignition B relay battery positive voltage circuit and the ignition B relay load circuit together at the underhood fuse block with a 20-amp fused jumper. Refer to Using Fused Jumper Wires.
  3. Probe the following fuses with a test lamp that is connected to a good ground:
    4. • The ENG 2 fuse
    • The ENG 3 fuse

Does the test lamp illuminate on at least one test point of each fuse?

Go to Step 35

Go to Step 34

34

Test the ignition B relay load bus bar circuit to the 15-amp ENG 2 fuse and the 15-amp ENG 3 fuse in the underhood fuse block for a high resistance or an open.

Did you find a condition?

Go to Step 57

Go to Step 56

35

Test for an intermittent and for a poor connection at the underhood fuse block, ignition B relay connector location. Refer to Testing for Intermittent Conditions and Poor Connections.

Did you find a condition?

Go to Step 60

Go to Step 58

36

Repair the short to battery positive voltage in the relay load circuit between the ignition B relay and the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

37

Repair the short to battery positive voltage in the ignition B relay load bus bar circuit to the 15-amp ENG 2 fuse and the 15-amp ENG 3 fuse of the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

38

Repair the short to battery positive voltage in the ignition 1 voltage circuit between the I/P fuse block and the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

39

Repair the short to battery positive voltage in the ignition 1 voltage bus bar of the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

40

Repair the short to battery positive voltage in the ignition 1 voltage circuit between the ignition switch and the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

41

Repair the short to ground in the battery positive voltage circuit between the 50-amp ENGINE fuse and the ignition B relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

42

Repair the short to ground in the ignition B relay load circuit to the 15-amp ENG 2 fuse. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

43

Repair the short to ground in the ignition B relay load circuit to the 15-amp ENG 3 fuse. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

44

Repair the high resistance or an open in the battery positive voltage bus bar circuit to the 50-amp ENGINE fuse in the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

45

Repair the short to ground in the ignition 1 voltage circuit between the 15-amp PCM 1 fuse and the ignition B relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

46

Repair the short to ground in the battery positive voltage circuit between the 40-amp IGN 1 fuse and the ignition switch. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

47

Repair the short to ground in the ignition 1 voltage circuit between the 15-amp PCM 1 fuse and the ignition switch. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

48

Repair the short to ground in the ignition 1 voltage bus bar circuit of the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

49

Repair the high resistance or an open in the battery positive voltage circuit to the ignition switch. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

50

Repair the high resistance or an open in the ignition 1 voltage bus bar circuit to the 15-amp PCM 1 fuse of the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

51

Repair the high resistance or an open in the ignition 1 voltage circuit between the ignition switch and the I/P fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

52

Repair the high resistance or an open in the battery positive voltage bus bar circuit to the 40-amp IGN 1 fuse of the MaxiFuse block assembly. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

53

Repair the high resistance or an open in the battery positive voltage circuit between the 50-amp ENGINE fuse and the ignition B relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

54

Repair the high resistance or an open in the ignition 1 voltage circuit between the 15-amp PCM 1 fuse and the ignition B relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

55

Repair the high resistance or an open in the coil ground circuit of the ignition B relay. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

56

Repair the high resistance or an open in the relay load circuit between the ignition B relay and the 15-amp ENG 2 fuse. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

57

Repair the high resistance or an open in the ignition B relay load bus bar circuit of the underhood fuse block. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 61

--

58

Replace the ignition B relay. Refer to Relay Replacement.

Did you complete the replacement?

Go to Step 61

--

59

Replace the ignition switch.

Did you complete the replacement?

Go to Step 61

--

60

Replace the ignition B relay wire terminals at the underhood fuse block. Refer to Repairing Connector Terminals.

Did you complete the replacement?

Go to Step 61

--

61
  1. Replace any open fuses.
  2. Turn OFF the ignition for 30 seconds.
  3. Attempt to start the engine.

Does the engine start and run?

Go to Step 62

Go to Engine Cranks But Does Not Run

62
  1. Clear the DTCs with a scan tool.
  2. Operate the vehicle for 5 minutes.

Does a DTC set during this ignition cycle?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK