P1DB8

P1DB8-UNINTENDED TORQUE APPLIED WHILE IN NEUTRAL

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The purpose of the diagnostic is to detect an unwanted power flow in the transmission. A rationality check of the ratio of input speed to engine speed is done while no power flow is requested.

- When Monitored:
No failure in input speed signal.

No failure in engine speed signal.

Engine speed greater than a calibrated threshold.

No mechanical limp home mode active.

No power flow requested.

- Set Condition:
The failure is detected if the ratio of input speed to engine speed is less than a calibrated threshold for an amount of time.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 8HP45 Pre-Diagnostic Troubleshooting Procedure

1. CHECK FOR INCORRECT GEAR RATIO DTCS
1. With the scan tool, read TCM DTCs.

Are any Incorrect Gear Ratio DTCs present?

Yes

- Repair any Incorrect Gear Ratio DTCs before proceeding.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Go To 2

2. CHECK IF DTC IS CURRENT

NOTE: The Transmission Control Module stores under Environmental Data the transmission operating conditions when the DTC was set. Before clearing any DTCs, record all information pertaining to the DTC.

1. With the scan tool, CLEAR transmission DTCs.
2. Using the Environmental Data previously recorded, drive the vehicle and try to duplicate the condition in which the DTC set.

Does the DTC reset?

Yes

- Go To 3

No

- Go To 4

3. TRANSMISSION CONTROL MODULE ASSEMBLY (TCMA)

If there are no possible causes remaining, view repair.

Repair

- Using the schematics as a guide, check the TCMA terminals for corrosion, damage or terminal push out. Pay particular attention to power and ground circuits. Check Service Information Tune-ups or Service Bulletins for possible causes that may apply. Connect the scan tool and clear the DTC. If the DTC returns, replace and program the TCMA. Valve Body - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

4. INTERMITTENT WIRING AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wiring and connectors while checking for any possible open or shorted circuits.
4. Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Test Complete.