Schematic Reference: Starting and Charging Schematics

Connector End View Reference: Power and Grounding Connector End Views

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

Turn the ignition switch to the start position.

Does the engine crank?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, observe the starter relay Command parameter in the engine control module (ECM) data list.
4. Turn the ignition switch to the start position.

Does the scan tool display ON?

Go to Step 5

Go to Step 4

1. Turn ON the ignition, with the engine OFF.
2. Verify that the transmission is in Park or Neutral.
3. With a scan tool, observe the PNP switch parameter in the engine control module (ECM) data list.

Does the scan tool display Park/Neutral?

Go to Step 6

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Turn the ignition switch to the start position.

Did the start relay click?

Go to Step 8

Go to Step 6

1. Turn OFF the ignition.
2. Remove the START relay.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the control circuit of the START relay coil and a good ground.
5. Turn the ignition switch to the start position.

Does the test lamp illuminate?

Go to Step 7

Go to Step 15

1. Connect a test lamp between the control circuit of the START relay coil and the ground circuit of the START relay.
2. Turn the ignition switch to the start position.

Does the test lamp illuminate?

Go to Step 8

Go to Step 12

1. Turn ON the ignition.
2. Connect a test lamp between the battery positive voltage circuit of the START relay switch circuit and a good ground.
3. Turn the ignition switch to the start position.

Does the test lamp illuminate?

Go to Step 9

Go to Step 17

Important: Ensure the parking brake is applied and the transmission is in park equipped with an automatic transmission or neutral on a manual transmission.

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

Does the engine crank?

Go to Step 13

Go to Step 10

Does the fuse in the jumper open?

Go to Step 18

Go to Step 11

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

Did you find and correct the condition?

Go to Step 22

Go to Step 14

Repair the ground circuit of the START relay. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 22

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Inspect for poor connections at the START relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 19

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

Did you find and correct the condition?

Go to Step 22

Go to Step 20

Repair an open or high resistance in the control circuit of the START relay coil. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 22

Go to Step 16

Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 21

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

Did you complete the repair?

Go to Step 22

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

Did you complete the repair?

Go to Step 22

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Replace the START relay.

Did you complete the replacement?

Go to Step 22

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Replace the starter motor. Refer to Starter Motor Replacement .

Did you complete the replacement?

Go to Step 22

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Replace the ECM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 22

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2