Transmission Control Indicator Lamp (TCIL)

TCS Switch:

OPERATION
The Transmission Control Switch (TCS) is a momentary contact switch. When the switch is pressed, a signal is sent to the Powertrain Control Module (PCM). The PCM then energizes the Transmission Control Indicator Lamp (TCIL) and the Coast Clutch Solenoid (CCS), applying the coast clutch to provide engine braking and cancels fourth gear operation. The TCIL Indicates overdrive cancel mode activated (lamp on), electronic pressure control circuit shorted or monitored sensor failure (lamp flashing).



PURPOSE
Disables fourth gear operation.

SYMPTOMS
^ No overdrive cancel when switch is cycled, (TCIL not flashing), electronic pressure control circuit shorted.

^ Failed off - overdrive cancel mode never indicated, (TCIL not flashing), electronic pressure control circuit shorted.

DIAGNOSTIC TROUBLE CODES:
- 65,97 (two digit)
- 632,631 (three digit), tested during Key On Engine Off (KOEO) On-Board Diagnostic only.