Beretta L4-138 2.3L DOHC QUAD 4 (1991)
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:
^
Coolant temperature must be above -10~C (14~F).
^
ECM can determine the transaxle has been in a gear for at least 1.2 seconds, by comparison of vehicle speed (from VSS) with engine rpm.
^
TPS is between minimum and maximum calibrated values for each gear.
^
Rpm is above a calibrated value for each gear (maximum 6500 rpm).
The light will be turned "ON" after a calibrated delay time which is dependent on last gear change or downshift, and will remain on for a minimum of 10
seconds.
