Torque Converter Diagnosis: Notes

WARNING: This page is about a different car, the 2008 Ford Pickup, 2008 Ford F550 Super Duty, 2008 Ford F450 Super Duty, and 2008 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

Prior to torque converter replacement, all diagnostic procedures must be followed. This is to prevent the unnecessary installation of new or remanufactured torque converters. Only after a complete diagnostic evaluation can the decision be made to install new or remanufactured torque converters.

NOTE: If equipped, turn the Power Take-Off (PTO) unit off for correct test results. For a description of PTO operation, refer to Transmission Electronic Control System .

During PTO operation, the On-Board Diagnostic (OBD) will be disabled. However, the circuit checks made by the diagnostic system and the Failure Mode Effect Management will continue. The PTO must be turned off to do OBD test.

Begin with the normal diagnostic procedures as follows:

Preliminary Inspection.
Know and Understand the Customer's Concern.
Verify the Concern - Carry out the Torque Converter Operation Test .
Carry out Diagnostic Procedures.
- Run OBD test. Refer to Carry out On-Board Diagnostic (OBD) .
  - Repair all non-transmission-related DTCs first.
  - Repair all transmission DTCs.
  - Rerun OBD test to verify repair.
- Carry out Line Pressure Test .
- Carry out Stall Speed Test .
- Carry out Diagnostic Routines .
  - Use the Diagnosis by Symptom Index to locate the appropriate routine that best describes the symptom(s). The routine will list all possible components that may cause or contribute to the symptom. Check each component listed. Diagnose and repair as required, before repairing the torque converter.