Cutlass L4-138 2.3L VIN A FI HP (1990)
Shift Light: Testing and Inspection
Chart C-8C
Chart C-8C Wiring Diagram
CIRCUIT DESCRIPTION:
The shift light indicates the best transaxle shift point for maximum fuel economy. The light is controlled by the ECM and is turned "ON" by grounding
CKT 456.
The ECM uses inputs from various sensors to calculate when the shift light should be turned "ON" as follows: