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

Apply the brake and press the Start button.

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,

Are DTCs B2515,C0277,C0278,P0615,P0616,P0617,P1875 Current?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 4

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. Apply the brake and press the Start button.

Does the scan tool display ON?

Go to Step 6

Go to Step 5

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

Apply the brake and press the Start button.

Do you hear the crank relay click?

Go to Step 9

Go to Step 7

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

Does the test lamp illuminate?

Go to Step 8

Go to Step 17

1. Connect a test lamp between the battery positive voltage circuit of the crank relay coil and the control circuit of the crank relay.
2. Apply the brake and press the Start button.

Does the test lamp illuminate?

Go to Step 9

Go to Step 13

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

Does the test lamp illuminate?

Go to Step 10

Go to Step 18

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 crank relay switch circuit and the supply voltage circuit of the starter solenoid.

Does the engine crank?

Go to Step 14

Go to Step 11

Does the fuse in the jumper open?

Go to Step 19

Go to Step 12

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 23

Go to Step 15

Test the control circuit of the crank relay for an open or short to battery voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 16

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

Did you find and correct the condition?

Go to Step 23

Go to Step 20

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 23

Go to Step 21

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 23

Go to Step 22

Repair an open or high resistance in the battery positive voltage circuit of the crank relay coil. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 23

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

Did you complete the repair?

Go to Step 23

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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 23

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Replace the crank relay.

Did you complete the replacement?

Go to Step 23

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Replace the starter motor. Refer to Starter Motor Replacement .

Did you complete the replacement?

Go to Step 23

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Replace the engine control module (ECM). Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 23

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2