Schematic Reference: Starting and Charging Schematics

Did you preform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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

Turn the ignition switch to the START position.

Does the starter motor relay click?

Go to Step 14

Go to Step 4

Is the vehicle equipped with a manual transmission?

Go to Step 5

Go to Step 7

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, observe the Clutch Start Switch Signal parameter in the PCM data list while depressing the clutch pedal.

Does the scan tool display Released/Applied?

Go to Step 7

Go to Step 6

1. Turn OFF the ignition.
2. Disconnect the powertrain control module (PCM) harness connector.
3. Connect a test lamp between the clutch start switch signal of the PCM harness and a good ground.
4. Turn the ignition to the START position while depressing the clutch pedal.

Does the test lamp illuminate?

Go to Step 10

Go to Step 11

1. Turn OFF the ignition.
2. Disconnect the PCM harness connector.
3. Connect a test lamp between the Crank Voltage circuit of the PCM harness and a good ground.
4. 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 10

Go to Step 8

Inspect for poor connections at the PCM connector, underhood fuse block or 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 32

Go to Step 9

Test the supply voltage circuit of the crank voltage circuit and Crank fuse for an open or high resistance. 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 32

Go to Step 30

1. Turn OFF the ignition.
2. Disconnect the PCM harness connector.
3. Connect a test lamp between the starter enable relay control circuit of the PCM harness and a good ground.
4. Turn the ignition to the START position.

Does the test lamp illuminate?

Go to Step 22

Go to Step 11

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 12

Go to Step 13

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 20

Go to Step 17

1. Turn OFF the ignition.
2. Disconnect the park neutral position (PNP) switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transmission - 4L60-E/4L65-E, Park/Neutral Position Switch Replacement in Automatic Transmission - 4L80-E/4L85-E, or Clutch Pedal Engine Start Switch Replacement in Clutch.
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 21

Go to Step 18

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 15

Go to Step 26

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 20

Go to Step 16

Does the fuse in the jumper open?

Go to Step 27

Go to Step 19

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 32

Go to Step 28

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 32

Go to Step 24

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 32

Go to Step 25

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 32

Go to Step 28

Did you find and correct the condition?

Go to Step 32

Go to Step 29

Inspect for poor connections at the harness connector of 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 32

Go to Step 23

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 32

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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 32

Go to Step 30

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 32

Go to Step 31

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 32

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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 32

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

Did you complete the replacement?

Go to Step 32

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1. Replace the PNP switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transmission - 4L60-E/4L65-E, Park/Neutral Position Switch Replacement in Automatic Transmission - 4L80-E/4L85-E.
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 32

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

Did you complete the replacement?

Go to Step 32

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Replace the starter. Refer to Starter Motor Replacement .

Did you complete the replacement?

Go to Step 32

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Operate the system for which the symptom occurred.

Did you correct the condition?

System OK

Go to Step 2