Shift Light: Testing and Inspection

Manual Transmission Shift Light Circuit:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) uses information from the following inputs to control the shift light:
- Engine Coolant Temperature (ECT) sensor.
- Throttle Position (TP) sensor.
- Vehicle Speed Sensor (VSS).
- RPM.

The PCM uses the measured RPM and the vehicle speed to calculate what gear the vehicle is in. It's this calculation that determines when the shift light should be turned "ON."

Manual Transmission Shift Light Check (1 Of 2):

Manual Transmission Shift Light Check (2 Of 2):

TEST DESCRIPTION:
Number below refer to step number on the Diagnostic Table:
2. Checks the PCM's ability to control the shift light.