Test C: Transmission Control Switch Inoperative

NOTE: Transmission control switch may also be known as overdrive control switch.

Turn ignition switch to OFF position. Disconnect Transmission Control Switch (TCS) harness connector C222. Measure resistance between ground and terminal No. 2 (Black wire) at TCS harness connector C222. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, repair open in Black wire.
Turn ignition switch to RUN position. Measure voltage between ground and terminal No. 1 (Green/Orange wire) at TCS harness connector C222. If voltage is greater than 10 volts, replace TCS. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. If voltage is not greater than 10 volts, go to next step.
Turn ignition switch to OFF position. Disconnect TCM harness connector C277A. Measure resistance of Green/Orange wire between terminal No. 22 at TCM harness connector C277A and terminal No. 1 at TCS harness connector C222. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, repair open in Green/Orange wire.
Turn ignition switch to ON position. Connect a fused (10-amp) jumper wire between ground and terminal No. 13 (Blue/Orange wire) at TCM harness connector C277A. If transmission control indicator (OD OFF) light illuminates, replace TCM. See TRANSMISSION CONTROL MODULE under REMOVAL & INSTALLATION. If OD OFF light does not illuminate, repair indicator light as necessary. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.