Skyhawk L4-121 2.0L Turbo VIN M FI (1987)
Shift Light: Testing and Inspection
Chart C-8B-2 M/T Shift Light Check: VIN 1 (2.0L)
Fig. 062 - Wiring Diagram for Chart C-8B-2 M/T Shift Light Check. VIN 1
CHART C-8B-2
M/T SHIFT LIGHT CHECK
2.0L (VIN 1) "J" SERIES
FUEL INJECTION (TBI)
Circuit Description:
The shift light 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:
a. Coolant temperature
b. TPS
c. VSS
d. RPM
The ECM 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".
