Operation CHARM: Car repair manuals for everyone.

Overdrive Electrical Controls

The overdrive off switch, valve body solenoid, case connectors and related wiring can all be tested with a 12 volt test lamp or a volt/ohmmeter. Check continuity of each component when diagnosis indicates this is necessary. Refer to Diagrams, for circuit and Locations for component locations information.

Switch and solenoid continuity should be checked whenever the transmission fails to shift into fourth gear range.