48RE Automatic Transmission - Diesel

P0882-TRANS 12 VOLT SUPPLY RELAY CONTROL CIRCUIT LOW (DIESEL)





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


Theory of Operation


The Transmission Control Output from the Totally Integrated Power Module (TIPM) supplies power to the TCC, Overdrive, and Governor Pressure Solenoids when in normal operating mode. The Transmission Control circuit is constantly monitored by the ECM. If the expected state of the Transmission Control circuit is different then the expected state, a corresponding DTC will set and the ECM will de-energize the Transmission Control and place the transmission in Limp-in.


- When Monitored:

Continuously with the Ignition on.

- Set Condition:

This DTC will set if the ECM monitored voltage of the Transmission Control Relay Control circuit is different than the expected voltage for the period 3.0 seconds.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Checkout (Diesel)




1. CHECK IF THE DTC IS CURRENT

Ignition on, engine not running.

With the scan tool, read Engine DTCs.

Record the Freeze Frame data for the reported DTC.

With the scan tool, erase DTCs.

Turn the ignition off to the lock position.

Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.


NOTE: It may be necessary to road test the vehicle to duplicate the original set conditions.

With the scan tool, read Engine DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Go To 5



2. CHECK THE TIPM FOR CODES

Ignition on, engine not running.

With the scan tool, read TIPM DTCs.

Are there any TIPM DTCs?

Yes

- Refer to the Transmission category and perform the appropriate symptom(s).

No

- Go To 3



3. CHECK THE (T515) TRANSMISSION CONTROL CIRCUIT





Turn the ignition off to the lock position.

Disconnect the TIPM C1 harness connector.

Ignition on, engine not running.

Using the scan tool in the ECM, actuate the Transmission.

Using a 12-volt test light connected to ground, check the (T515) Transmission Control circuit at the TIPM C1 harness connector.

Does the test light cycle on and off and illuminate brightly?

Yes

- Using the schematics as a guide, check the Totally Integrated Power Module (TIPM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the TIPM.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test

No

- Go To 4



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





Turn the ignition off to the lock position.

Disconnect the ECM C2 harness connector.

Connect a jumper wire between cavity 5 in the ECM C2 harness connector and ground.

Using a 12-volt test light connected to 12 volts, check the (T515) Transmission Control circuit at the TIPM C1 harness connector.

Does the test light illuminate brightly?

Yes

- Using the schematics as a guide, check the Engine Control Module (ECM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the ECM.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test

No

- Repair the (T515) Transmission Control circuit for an open.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test

5. INTERMITTENT WIRING AND CONNECTORS

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

Use the Freeze Frame Data to help duplicate the conditions in which the DTC originally set. Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT, and Load

Using the schematics as a guide, visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.

Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

Wiggle the wiring and connectors while checking for any possible open or shorted circuits.

Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test

No

- Test Complete.