68RFE Automatic Transmission

P128E-TCM POWER CONTROL CIRCUIT 2 OVERCURRENT - TIPM





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


- When Monitored:

With the ignition on. Battery voltage greater than 10 volts.

- Set Condition:

An overcurrent condition of the Transmission Control Output circuit is detected by the Totally Integrated Power Module (TIPM).







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



Diagnostic Test


1. CHECK IF THE DTC IS ACTIVE

Ignition on, engine not running.

With a scan tool, read TIPM DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Go To 5



2. CHECK THE (T16) TRANSMISSION CONTROL OUTPUT





Turn the ignition off to the lock position.

Disconnect the TIPM C10 harness connector.

Connect the positive probe of an ammeter to battery positive and connect the negative probe to the (T16) Transmission Control Output circuit in the TIPM C10 harness connector.

Read the amperage on the ammeter.

Does the amperage read below 2.0 amps?

Yes

- Go To 4

No

- Go To 3



3. CHECK THE PCM





Disconnect the amp meter from the TIPM C10 harness connector and battery positive.

Disconnect the PCM C4 harness connector.

Reconnect the positive probe of an ammeter to battery positive and connect the negative probe to the (T16) Transmission Control Output circuit in the TIPM C10 harness connector.

Read the amperage on the ammeter.

Does the amperage read below 2.0 amps?

Yes

- 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

No

- Go To 4



4. CHECK THE TRANSMISSION SOLENOIDS





Disconnect the amp meter from the TIPM C10 harness connector.

Disconnect the PCM C4 harness connector and install 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.

Connect the positive probe of an ammeter to battery positive and connect the negative probe to the (T16) Transmission Control Output circuit in the TIPM C10 harness connector.

While monitoring the amperage reading of the ammeter and using a jumper wire, jump each solenoid control circuit to ground one at a time in the appropriate terminals of Miller tool #8815.


NOTE: The amperage draw should be approximately.02 milliampere on each solenoid circuit with the PCM C4 harness connector disconnected.

Does the amperage read between .05 and .015 milliampere (±.005) milliampere on each solenoid tested?

Yes

- Replace the Totally Integrated Control Module.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test

No

- Replace Transmission Solenoid/TRS Assembly.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test


5. INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set the 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.

Were there any problems found?

Yes

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

No

- Test Complete.