GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Starting and Charging Schematics

1

Did you preform the Engine Electrical Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Engine Electrical

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

Turn the ignition switch to the START position.

Does the starter motor relay click?

Go to Step 7

Go to Step 4

4

  1. Remove the starter motor relay.
  2. Connect a test light from the supply voltage circuit of the starter motor relay coil circuit to ground.
  3. With the transmission in park, or clutch pedal depressed, turn the ignition switch to the START position.

Does the test light illuminate?

Go to Step 5

Go to Step 6

5

  1. Connect a test light from the supply voltage circuit of the starter motor relay coil circuit to the control circuit of the starter motor relay coil circuit.
  2. With the transmission in park, or clutch pedal depressed, turn the ignition switch to the START position.

Does the test light illuminate?

Go to Step 13

Go to Step 10

6

  1. Turn OFF the ignition.
  2. Disconnect the Park Neutral Position (PNP) switch Park/Neutral Position Switch Replacement 4L60-E, Park/Neutral Position Switch Replacement 4L80-E or Park/Neutral Position Switch Replacement (Allison) for the Automatic Transmissions or the Clutch Pedal Position switch Clutch Pedal Engine Start Switch Replacement for Manual Transmission.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a 10 amp fused jumper between the starter motor relay coil control circuits of the PNP switch or clutch pedal position switch.
  5. With the transmission in park, or clutch pedal depressed, turn the ignition switch to the START position.

Does the test lamp illuminate?

Go to Step 14

Go to Step 11

7

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

Does the test lamp illuminate?

Go to Step 8

Go to Step 17

8

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

Does the engine crank?

Go to Step 13

Go to Step 9

9

Does the fuse in the jumper open?

Go to Step 18

Go to Step 12

10

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

Did you find and correct the condition?

Go to Step 23

Go to Step 19

11

Test the supply voltage circuit of the starter motor relay coil circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 15

12

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

Did you find and correct the condition?

Go to Step 23

Go to Step 16

13

Inspect for poor connections at the starter motor 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 23

Go to Step 19

14

    • If equipped with an Automatic Transmission, inspect for poor connection at the PNP switch harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. If OK, perform the Park/Neutral Position Switch Adjustment 4L60-E, Park/Neutral Position Switch Adjustment 4L80-E or Park/Neutral Position Switch Adjustment (Allison) for Automatic Transmission.
    • If equipped with a Manual Transmission, inspect for poor connection at the clutch pedal position switch harness connector. 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 23

Go to Step 20

15

Inspect for poor connections at the ignition switch harness connector. 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 23

Go to Step 21

16

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 23

Go to Step 22

17

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

Did you complete the repair?

Go to Step 23

--

18

Repair the short to ground in the supply voltage circuit of the starter solenoid. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 23

--

19

Replace the Starter Relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 23

--

20

  1. Replace the PNP switch. Refer to Park/Neutral Position Switch Replacement 4L60-E, Park/Neutral Position Switch Replacement 4L80-E or Park/Neutral Position Switch Replacement (Allison) in Automatic Transmission.
  2. Replace the Clutch Pedal Position switch. Refer to Clutch Pedal Engine Start Switch Replacement in Clutch.

Did you complete the replacement?

Go to Step 23

--

21

Replace the Ignition Switch. Refer to Ignition Switch Replacement - On Vehicle in Steering Wheel and Column.

Did you complete the replacement?

Go to Step 23

--

22

Replace the starter. Refer to Starter Motor Replacement .

Did you complete the replacement?

Go to Step 23

--

23

Operate the system for which the symptom occurred.

Did you correct the condition?

System OK

Go to Step 2