68RFE Automatic Transmission

P0882-TCM POWER INPUT LOW





For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


Theory of Operation


The Transmission Control Output circuit is used to supply power to the Transmission Solenoid/TRS Assembly and to the PCM when in normal operating mode. The purpose of the Transmission Output circuit is to allow the Transmission Control System to turn off the power to the Transmission Solenoid/TRS Assembly in event that the transmission should need to be placed into "limp-in" mode due to a DTC.


After a PCM reset, (ignition switch turned to the run position, or after cranking the engine) the Transmission Control System verifies that the Transmission Output circuit is open by checking for voltage on the Transmission Output circuits before the Transmission Control System request for the circuit to be powered up. The request is sent by a direct circuit control from the PCM to the TIPM. If the Transmission Control System detects less that 3.0 volts when the output is commanded on, the DTC will set. Note: Inadequate Transmission Control Output voltage can also cause DTCs P0846, P0869, P0871, P0876 or P0988 to set. Repairing the P0882 fault should also eliminate the related DTCs.


- When Monitored:

When the ignition is turned from "OFF" position to "RUN" position and/or the ignition is turned from "START" position to "RUN" position.

- Set Condition:

This DTC is set when there is less than 3.0 volts present at the transmission control output circuits located in the Powertrain Control Module (PCM) when the Transmission Control System request the power up of those circuits..







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 68RFE Pre-Diagnostic Troubleshooting Procedure


Diagnostic Test


1. CHECK IF THE DTC P0882 IS CURRENT

With the scan tool, Check the STARTS SINCE SET counter for P0882.


NOTE: This counter only applies to the last DTC set.

Is the STARTS SINCE SET counter equal to 0?

Yes

- Go To 2

No

- Go To 5



2. CHECK FOR TIPM RELATED DTCS

With the scan tool, check TIPM DTCs.

Are there any TIPM TCM Power Control Circuit DTCs present?

Yes

- Refer to the Transmission category and perform the appropriate symptom.

No

- Go To 3



3. CHECK THE (T515) TRANSMISSION CONTROL CIRCUIT FOR A SHORT TO GROUND





Turn the ignition off to the lock position.

Disconnect the PCM C4 harness connector and connect Miller tool #8815.


CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller tool #8815 to perform diagnosis.

Disconnect the TIPM C1 harness connector.

Measure the resistance between ground and the (T515) Transmission Control circuit.

Is the resistance below 5.0 ohms?

Yes

- Repair the (T515) Transmission Control circuit for a short to ground.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test

No

- Go To 4



4. CHECK THE (T515) TRANSMISSION CONTROL CIRCUIT FOR AN OPEN





Measure the resistance of the (T515) Transmission Control circuit between the TIPM C1 harness connector and the appropriate terminal of Miller tool #8815.

Is the resistance above 5.0 ohms?

Yes

- Repair the (T515) Transmission Control circuit for an open.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test

No

- Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the PCM. With the scan tool, perform QUICK LEARN.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test



5. CHECK THE WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

Wiggle the wires while checking for shorted and open circuits.

With the scan tool, check the DTC EVENT DATA to help identify the conditions in which the DTC was set.

Where there any problems found?

Yes

- Repair as necessary.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test

No

- Test Complete.