P128B

P128B-TCM POWER CONTROL CIRCUIT 2 LOW





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

- When Monitored:
With the ignition on. Battery voltage greater than 10.0 volts.

- Set Condition:
A shorted condition is detected in the Transmission Control Output circuit.





Always perform the CVT Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.

1. CHECK IF THE DTC IS ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, check Transmission DTCs.

Are there any Speed Sensor or Transmission Range Sensor DTCs present?

Yes

- Refer to DTC Based Diagnostics and perform the appropriate diagnostic procedure.

No

- Go To 2

2. CHECK IF THE DTC IS ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, check TIPM DTCs.

Is the status Active for this DTC?

Yes

- Go To 3

No

- Go To 6

3. CHECK THE (T16) TRANSMISSION CONTROL OUTPUT CIRCUIT SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the TIPM C8 harness connector.
3. Disconnect the TCM C1 harness connector.
4. Measure the resistance between ground and the (T16) Transmission Control Output circuit.

Is the resistance below 5.0 Ohms?

Yes

- Repair the (T16) Transmission Control Output circuit for a short to ground.
- Perform the CVT TRANSMISSION VERIFICATION TEST. CVT Transmission Verification Test.

No

- Go To 4

4. CHECK THE (T16) TRANSMISSION CONTROL OUTPUT CIRCUIT FOR AN OPEN
1. Turn the ignition off to the lock position.
2. Reconnect the TIPM C8 harness connector.
3. Ignition on, engine not running.
4. Using the scan tool under the TIPM Actuators, actuate the Transmission.
5. Using a 12-volt test light connected to ground, check the (T16) Transmission Control Output circuits.

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 at all the (T16) Transmission Control Output circuits?

Yes

- Go To 5

No

- Repair the (T16) Transmission Control Output circuit for an open.
- Perform the CVT TRANSMISSION VERIFICATION TEST. CVT Transmission Verification Test.

5. TOTALLY INTEGRATED POWER MODULE
1. Using the schematics as a guide, inspect the wire harness and connectors.
2. Check the TIPM harness connector terminals for corrosion, damage, or terminal push out.
3. Pay particular attention to all power and ground circuits.

Were any problems found?

Yes

- Repair as necessary.
- Perform the CVT TRANSMISSION VERIFICATION TEST. CVT Transmission Verification Test.

No

- Replace and program the TIPM.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

6. CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
3. While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.
4. Look for the data to change or for the DTC to reset during the wiggle test.

Were any problems found?

Yes

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

No

- Test complete.