P1278

P1278-STARTER CONTROL CIRCUIT 2 HIGH - DIESEL

For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
With the ignition on. Battery voltage greater than 10.4 volts and the ASD sense switch is on.

- Set Condition:
Actual Starter state is not equal to desired state. One Trip Fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With a scan tool, select View DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition Test.

2. (T750) STARTER CONTROL OUTPUT CIRCUIT SHORTED TO BATTERY VOLTAGE
1. Turn the ignition off.
2. Disconnect the Starter Solenoid connector.
3. Disconnect the C9 TIPM harness connector.
4. Using a 12-volt test light connected to ground, probe (T750) Starter Control Output circuit in the Starter Solenoid harness connector.

Does the test light illuminate brightly?

Yes

- Repair the short to voltage in the (T750) Starter Control Output circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 3

3. STARTER
1. Turn the ignition off.
2. Connect the C9 TIPM harness connectors.

NOTE: The Stater Solenoid harness connector must remain disconnected at this time.

3. Have an assistant turn the ignition key to the CRANK position.
4. Using a 12-volt test light connected ground, probe the (T750) Stater Control Output circuit in the Starter Solenoid harness connector while the ignition key is in the CRANK position.

Does the test light illuminate brightly?

Yes

- Replace the Starter
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 4

4. TOTALLY INTEGRATED POWER MODULE

NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

1. Using the schematics as a guide, inspect the wire harness and connectors.
2. Pay particular attention to all Power and Ground circuits.

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace the Totally Integrated Power Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test