Operation CHARM: Car repair manuals for everyone.
Hosted by mcallihan.com

Shift Light: Description and Operation

PURPOSE
The first to fourth shift indicator lamp is controlled by the Powertrain Control Module (PCM). The lamp tells the driver to shift transmission into fourth gear on the next upshift.


CONDITIONS
The PCM illuminates the shift lamp, when:
- Engine coolant excedes 41° C (104° F).
- Vehicle speed is 12 to 18 mph.
- Transmission is in first gear.
- Engine speed over 608 rpm.
- The PCM verified above condition.
- Throttle position is less than 23 percent.