GM Service Manual Online
For 1990-2009 cars only

The control solenoid (w/body and TCM) valve assembly cleaning procedure is a specific software based routine, which resides in the TCM. This procedure is activated by the scan tool and is used to cycle the solenoids and valves in the control solenoid valve assembly in an attempt to dislodge debris and free up the valves after a performance diagnostic trouble code (DTC) has set. The transmission fluid is drained and refilled with new fluid, and then the cleaning procedure is performed. When the cleaning procedure is completed, the DTC enable criteria is run again, and retested to see if the DTC concern has been corrected.

    Important: The fluid pan must be removed in order to drain the fluid.

  1. Drain and refill the transmission fluid. Refer to Automatic Transmission Fluid, Fluid Pan and/or Filter Replacement.
  2. Operate the transmission to achieve 70°-90°C (158°-194°F).
  3. With a scan tool, select the Service Cleaning Procedure. Initiate the cleaning procedure.
  4. When the cleaning procedure is completed, shut OFF the ignition for 30 seconds.