P1C8C-16

P1C8C-16-SYSTEM VOLTAGE-CIRCUIT VOLTAGE BELOW THRESHOLD

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The Electronic Shift Module (ESM) monitors ignition voltage. The DTC sets if the monitored battery voltage drops below 6.0 volts and a temporary limp in will be activated. If the voltage rises above 9.0 volts, normal operations is resumed.

- When Monitored:
Continuously with the ignition in the run position.

- Set Condition:
When monitored battery voltage drops below 6.0 volts.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 8HP45 Pre-Diagnostic Troubleshooting Procedure

1. CHECK FOR ENGINE CHARGING SYSTEM DTCS
1. With the scan tool, read Engine DTCs.

Are any Engine Charging System DTCs present?

Yes

- Charging System Perform the appropriate diagnostic procedure.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Go To 2

2. CHECK ESM POWER CIRCUIT
1. Turn the ignition OFF to the LOCK position.
2. Disconnect the ESM harness connector.
3. Ignition ON, engine NOT running.
4. Using a 12-volt test light connected to ground, check the ESM power circuit in the Shift Lever Assembly harness connector.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 3

No

- Repair the ESM power circuit for high resistance.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

3. CHECK GROUND CIRCUIT
1. Turn the ignition OFF to the LOCK position.
2. Using a 12-volt test light connected to 12-volts, check the ESM ground circuit in the Shift Lever Assembly harness connector.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 4
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Repair the ground circuit for high resistance.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

4. ELECTRONIC SHIFT MODULE
1. Reconnect all disconnected harness connectors.
2. With the scan tool, clear ESM DTC's.
3. Start the engine and raise the engine speed to 2,000 rpm for 10 seconds.
4. With the scan tool, read ESM DTC's.

Did the DTC reset?

Yes

- Using the schematics as a guide, check the Electronic Shift Module (ESM) terminals for corrosion, damage or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the ESM. Transmission Shifter - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Test Complete.