GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Starting and Charging Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Turn the ignition switch to the START position.

Does the engine crank?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Important: A flashing or illuminated security lamp indicates a theft deterrent malfunction. A theft deterrent malfunction may disable starter operation.

Is the security lamp flashing?

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

Go to Step 4

4

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Crank Request Signal parameter in the powertrain control module (PCM) data list.
  4. Turn the ignition switch to the START position.

Does the scan tool display Yes?

Go to Step 5

Go to Step 14

5

Turn the ignition switch to the START position.

Does the starter relay click?

Go to Step 6

Go to Step 9

6

  1. Turn OFF the ignition.
  2. Disconnect the starter relay.
  3. Connect a test lamp between the battery positive voltage circuit of the starter relay switch circuit and a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 25

7

Connect a 30-amp fused jumper between the battery positive voltage circuit of the starter relay switch circuit and the supply voltage circuit of the starter solenoid.

Does the engine crank?

Go to Step 19

Go to Step 8

8

Does the fuse in the jumper open?

Go to Step 15

Go to Step 16

9

  1. Turn OFF the ignition.
  2. Disconnect the starter relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the battery positive voltage circuit of the starter relay coil and a good ground.

Does the test lamp illuminate?

Go to Step 10

Go to Step 12

10

  1. Connect a test lamp between the battery positive voltage circuit of the starter relay coil and the control circuit of the starter relay.
  2. Turn the ignition ON, with the engine OFF.

Does the test lamp illuminate?

Go to Step 26

Go to Step 11

11

Turn the ignition to the START position.

Does the test lamp illuminate?

Go to Step 19

Go to Step 17

12

  1. Turn OFF the ignition.
  2. Disconnect the park neutral position (PNP) switch.
  3. Connect a 3-amp fused jumper between the PNP switch signal circuit and the ignition 1 voltage circuit of the PNP switch.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 20

Go to Step 13

13

Connect a test lamp between the ignition 1 voltage circuit of the PNP switch and a good ground.

Does the test lamp illuminate?

Go to Step 27

Go to Step 28

14

  1. Turn OFF the ignition.
  2. Disconnect the PCM.
  3. Connect a test lamp between the crank request signal circuit of the PCM and a good ground.
  4. Turn the ignition to the start position.

Does the test lamp illuminate?

Go to Step 22

Go to Step 18

15

Test the supply voltage circuit of the starter solenoid for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 23

16

Test the supply voltage circuit of the starter solenoid for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 23

17

Test the control circuit of the starter relay for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 22

18

Test the crank request circuit of the PCM for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 24

19

Inspect for poor connections at the starter relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 29

20

Inspect the PNP switch for proper operation.

Did you find and correct the condition?

Go to Step 34

Go to Step 21

21

Inspect for poor connection at the PNP switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 30

22

Inspect for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 31

23

Inspect for poor connections at the starter solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 32

24

Inspect for poor connections at the ignition switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 34

Go to Step 33

25

Repair the high resistance or open in the battery positive voltage circuit of the starter relay switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 34

--

26

Repair the short to ground in the control circuit of the starter relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 34

--

27

Repair the high resistance or open in the park/neutral signal circuit of the PNP switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 34

--

28

Repair the high resistance or open in the ignition 1 circuit of the PNP switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 34

--

29

Replace the starter relay.

Did you complete the replacement?

Go to Step 34

--

30

Replace the neutral safety switch.

Did you complete the replacement?

Go to Step 34

--

31

Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 34

--

32

Replace the starter motor. Refer to Starter Motor Replacement .

Did you complete the replacement?

Go to Step 34

--

33

Replace the ignition switch. Refer to Ignition and Start Switch Replacement in Steering Wheel and Column.

Did you complete the replacement?

Go to Step 34

--

34

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2