P127A

P127A-STARTER CONTROL CIRCUIT 2 OVERCURRENT

P127A - Starter Control Circuit 2 Overcurrent:

WHEN MONITORED:
With the ignition on. Battery voltage greater than 10.4 volts.

SET CONDITION:
The TIPM has detected on overcurrent condition in the Starter Control circuit. One Trip Fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES
- (T40) Starter relay output circuit excessive resistance
- (T40) Starter relay output circuit shorted to ground
- (T750) Starter relay output circuit excessive resistance
- (T750) Starter relay output circuit shorted to ground
- Starter relay
- Starter
- TIPM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

DIAGNOSTIC TEST

1. ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.

Q: Is the DTC active at this time?

YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Component Tests and General Diagnostics
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. (T750) STARTER RELAY OUTPUT CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Remove the Starter Relay.
Disconnect the Starter Solenoid harness connector.
Measure the resistance between ground and the (T750) Starter Relay Output circuit at the Starter Relay harness connector.

Q: Is the resistance below 100 ohms?

YES: Repair the short to ground in the (T750) Starter Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 3

3. (T750) STARTER RELAY OUTPUT CIRCUIT EXCESSIVE RESISTANCE
Measure the resistance of the (T750) Starter Relay Output circuit from the Starter Relay terminal to the Starter Solenoid harness connector.

Q: Is the resistance above 5.0 ohms?

YES: Repair the excessive resistance in the (T750) Starter Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4

4. (T40) STARTER RELAY OUTPUT CIRCUIT SHORTED TO GROUND
Disconnect the C9 TIPM harness connector.
Measure the resistance between ground and the (T40) Starter Relay Output circuit at the C9 TIPM harness connector.

Q: Is the resistance below 100 ohms?

YES: Repair the short to ground in the (T40) Starter Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 5

5. (T40) STARTER RELAY OUTPUT CIRCUIT EXCESSIVE RESISTANCE
Measure the resistance of the (T40) Starter Relay Output circuit from the Starter Relay terminal to the C9 TIPM harness connector.

Q: Is the resistance above 5.0 ohms?

YES: Repair the excessive resistance in the (T40) Starter Relay Feed circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 6

6. STARTER RELAY
Install a known good Relay.
Ignition on, engine not running.
Clear the TIPM DTCs.
Attempt to start the engine.

Q: Does the P127A reset?

YES: Go To 7
NO: Replace the Starter Relay. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

7. TOTALLY INTEGRATED POWER MODULE

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

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

Q: 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 VER - 1. Body Verification Test