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 in Engine Electrical.
Step | Action | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics , Power Distribution Schematics , Ground Distribution Schematics Connector End View Reference: Engine Control Module Connector End Views and Engine Controls Connector End Views | |||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |||||||||||
2 |
Does the test lamp illuminate on both test points of the fuse? | Go to Step 3 | Go to Step 12 | ||||||||||
3 |
Does the test lamp illuminate on either test point of the fuse? | Go to Step 4 | Go to Step 61 | ||||||||||
4 |
Notice: Refer to Test Probe Notice in the Preface section. Does the test lamp illuminate? | Go to Step 8 | Go to Step 5 | ||||||||||
5 |
Does the test lamp illuminate at any of the fuse terminals? | Go to Step 6 | Go to Step 58 | ||||||||||
6 |
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 in Wiring Systems. Did you find a condition? | Go to Step 37 | Go to Diagnostic System Check - Engine Electrical in Engine Electrical | ||||||||||
8 |
Does the test lamp illuminate? | Go to Step 38 | Go to Step 9 | ||||||||||
9 |
Does the test lamp illuminate? | Go to Step 10 | Go to Step 11 | ||||||||||
10 |
Did you find a condition? | Go to Step 39 | Go to Step 40 | ||||||||||
11 |
Does the test lamp illuminate? | Go to Step 59 | Go to Step 58 | ||||||||||
12 |
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 |
Notice: Refer to Test Probe Notice in the Preface section. Does the test lamp illuminate? | Go to Step 41 | Go to Step 15 | ||||||||||
15 |
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 in Wiring Systems. Did you find a condition? | Go to Step 42 | Go to Step 43 | ||||||||||
17 |
Does the test lamp illuminate? | Go to Step 44 | Go to Diagnostic System Check - Engine Electrical in Engine Electrical | ||||||||||
18 |
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 |
Notice: Refer to Test Probe Notice in the Preface section. Does the test lamp illuminate? | Go to Step 45 | Go to Step 58 | ||||||||||
21 |
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 |
Does the test lamp illuminate? | Go to Step 46 | Go to Step 24 | ||||||||||
24 |
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:
Did you find a condition? | Go to Step 48 | Go to Step 59 | ||||||||||
26 |
Does the test lamp illuminate? | Go to Step 27 | Go to Step 49 | ||||||||||
27 |
Does the test lamp illuminate? | Go to Step 28 | Go to Step 59 | ||||||||||
28 |
Does the test lamp illuminate? | Go to Step 50 | Go to Step 51 | ||||||||||
29 |
Does the test lamp illuminate? | Go to Step 52 | Go to Diagnostic System Check - Engine Electrical in Engine Electrical | ||||||||||
30 |
Notice: Refer to Test Probe Notice in the Preface section. Does the test lamp illuminate? | Go to Step 31 | Go to Step 53 | ||||||||||
31 |
Does the test lamp illuminate? | Go to Step 32 | Go to Step 54 | ||||||||||
32 |
Does the test lamp illuminate? | Go to Step 33 | Go to Step 55 | ||||||||||
33 |
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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. Did you complete the repair? | Go to Step 61 | -- | ||||||||||
58 | Replace the ignition A relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 61 | -- | ||||||||||
59 | Replace the ignition switch. Refer to Ignition and Start Switch Replacement in Steering Wheel and Column. 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 in Wiring Systems. Did you complete the replacement? | Go to Step 61 | -- | ||||||||||
61 |
Does the engine start and run? | Go to Step 62 | |||||||||||
62 |
Does a DTC set during this ignition cycle? | 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 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 through the engine control module (ECM). 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 will 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 in Engine Electrical.
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Power Distribution Schematics and Ground Distribution Schematics in Wiring Systems, Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views and Engine Controls Connector End Views | |||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |||||||
2 |
Does the test lamp illuminate on at least one test point of the fuse? | Go to Step 3 | Go to Step 7 | ||||||
3 |
Does the test lamp illuminate on either test point of the fuse? | Go to Step 4 | Go to Step 34 | ||||||
4 |
Notice: Refer to Test Probe Notice in the Preface section. Does the test lamp illuminate? | Go to Step 5 | Go to Step 30 | ||||||
5 |
Does the test lamp illuminate? | Go to Step 20 | Go to Step 6 | ||||||
6 |
Did you find a condition? | Go to Step 21 | Go to Diagnostic System Check - Engine Electrical in Engine Electrical | ||||||
7 |
Does the test lamp illuminate on both test points of the fuse? | Go to Step 13 | Go to Step 8 | ||||||
8 | Does the test lamp illuminate on one test point of the 50-amp ENGINE fuse? | Go to Step 9 | Go to Step 12 | ||||||
9 |
Notice: Refer to Test Probe Notice in the Preface section. Does the test lamp illuminate on either relay terminal? | Go to Step 22 | Go to Step 10 | ||||||
10 |
Does the test lamp illuminate? | Go to Step 23 | Go to Step 11 | ||||||
11 | Test the ignition B relay load bus bar circuit that leads to the 15-amp ENG 2 fuse and the 25-amp ENG 3 fuse in the underhood fuse block for a short to ground. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 24 | Go to Step 30 | ||||||
12 |
Does the test lamp illuminate? | Go to Step 25 | Go to Diagnostic System Check - Engine Electrical in Engine Electrical | ||||||
13 |
Notice: Refer to Test Probe Notice in the Preface section. Does the test lamp illuminate for both circuits? | Go to Step 14 | Go to Step 26 | ||||||
14 |
Does the test lamp illuminate? | Go to Step 15 | Go to Step 16 | ||||||
15 |
Does the test lamp illuminate on at least one test point of each fuse? | Go to Step 18 | Go to Step 17 | ||||||
16 |
Did you find a condition? | Go to Step 27 | Go to Step 19 | ||||||
17 | Test the ignition B relay load bus bar circuit to the 15-amp ENG 2 fuse and the 25-amp ENG 3 fuse in the underhood fuse block for a high resistance or for an open. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 29 | Go to Step 28 | ||||||
18 | Test for an intermittent and for a poor connection at the ignition B relay connector location of the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find a condition? | Go to Step 32 | Go to Step 30 | ||||||
19 | Test for an intermittent and for a poor connection at the ECM connectors. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find a condition? | Go to Step 33 | Go to Step 31 | ||||||
20 | Repair the short to battery positive voltage in the relay load circuit between the ignition B relay and the 15-amp ENG 2 fuse and the 25-amp ENG 3 fuse in the underhood fuse block. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
21 | Repair the short to battery positive voltage in the ignition B relay load bus bar circuit to the 15-amp ENG 2 fuse and to the 25-amp ENG 3 fuse of the underhood fuse block. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
22 | 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 in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
23 | Repair the short to ground in the ignition B relay load circuit to the 15-amp ENG 2 fuse and the 25-amp ENG 3 fuse. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
24 | Repair the short to ground in the ignition B relay load bus bar circuit to the 15-amp ENG 2 fuse and the 25-amp ENG 3 fuse in the underhood fuse block. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
25 | 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 in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
26 | 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 in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
27 | Repair the high resistance or an open in the coil ground circuit from the ignition B relay to the ECM. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
28 | Repair the high resistance or an open in the relay load circuit between the ignition B relay and the 15-amp ENG 2 fuse and the 25-amp ENG 3 fuse. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
29 | Repair the high resistance or an open in the ignition B relay load bus bar circuit to the 15-amp ENG 2 fuse and the 25-amp ENG 3 fuse of the underhood fuse block. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
30 | Replace the ignition B relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 34 | -- | ||||||
31 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | Go to Step 34 | -- | ||||||
32 | Replace the ignition B relay wire terminals at the underhood fuse block. Refer to Repairing Connector Terminals in Wiring Systems. Did you complete the replacement? | Go to Step 34 | -- | ||||||
33 | Replace the ECM terminals. Refer to Repairing Connector Terminals in Wiring Systems. Did you complete the replacement? | Go to Step 34 | -- | ||||||
34 |
Does the engine start and run? | Go to Step 35 | |||||||
35 |
Does a DTC set during this ignition cycle? | System OK | |||||||
