GM Service Manual Online
For 1990-2009 cars only

Causes

Action

The Solenoid Valve for the Converter Clutch is defective.

Refer to DTC P1870 Transmission Component Slipping .

There is an interruption in the Signal Circuit.

Perform the Line Pressure Check .

There is fluid loss in the Fluid Circuit of the Converter Clutch.

  1. Search for the leaking part.
  2. Replace the leaking part.