Chart C-8B-1 M/T Shift Light Check: VIN K, VIN R & VIN U

Fig. 017 Chart C-8B-1 M/T Shift Light Check:

Fig. 018 Wiring Diagram for C-8B-1 M/T Shift Light Check:

CHART C-8B-1

M/T SHIFT LIGHT CHECK

2.0L OHC (VIN K) "J" SERIES

2.5L "A, N & P" SERIES

FUEL INJECTION (TBI)




Circuit Description: The shift indicates the best transmission shift point for maximum fuel economy. The light is controlled by the ECM and is turned on by grounding CKT 456.
The ECM uses information from the following inputs to control the shift light:
Coolant temperature
TPS
VSS
RPM
The ECM uses the measured rpm and the vehicle speed to calculate what gear the vehicle is in. It is this calculation that determines when the shift light should be turned "ON".



Test Description: Numbers below refer to circled numbers on Diagnostic Chart
1. This should not turn "ON" the shift light. If the light is "ON", there is a short to ground in CKT 456 wiring, or a fault in the ECM.
2. When the diagnostic terminal is grounded, the ECM should ground CKT 456, and the shift light should come "ON".
3. This checks the shift light circuit up to the ECM connector. If the shift light illuminates, then the ECM connector is faulty, or the ECM does not have the ability to ground the circuit.