P128B

P128B - Transmission Power Control Circuit 2 Low






For a complete wiring diagram, refer to.

• When Monitored: With the ignition ON and the battery voltage greater than 10 volts.

• Set Condition: The totally integrated power module has detected a short or open condition in the transmission control output circuit.






Test Step 1 - Determine if the DTC is Active

• Ignition ON, engine not running.

• With the scan tool, read DTCs.

Is the status Active for this DTC?

Yes

• Go to Test Step 2.

No

• Go to Test Step 4.

Test Step 2 - Test the Transmission Control Output Circuit for a Short to Ground






• Turn the ignition switch to the LOCK position.

• Disconnect the TIPM harness connector.

• Disconnect the PCM harness connector and install Miller tool #8815.


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.

• Measure the resistance between ground and the transmission control output.

Is the resistance less than 5.0 ohms?

Yes

• Repair the circuit for a short to ground.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

• Go to Test Step 3.

Test Step 3 - Test the Transmission Control Output Circuit for an Open






• Connect the TIPM harness connector.

• Disconnect the transmission solenoid harness connector.

• Ignition ON, engine not running.

• Using the scan tool under the TIPM actuators, actuate the transmission.

• Using a test lamp connected to ground, test the transmission control output circuit at the appropriate terminals of Miller tool #8815.

• The test lamp must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test lamp illuminate brightly?

Yes

• Using the schematics as a guide, check the TIPM terminals for corrosion, damage, water intrusion, or terminal push out. Check for any service bulletins that may apply. If no problems are found, replace and program the TIPM.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

• Repair the circuit for an open.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 4 - Intermittent Wiring and Connectors

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

• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

• While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.

• 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 the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

• Test complete.