Shift Select System Diagnosis

Circuit Description

The shift select system allows the driver to select one of two shift patterns, NORMAL or PERFORMANCE. The PERFORMANCE / NORMAL switch is a normally open switch, that when closed, provides a ground path to the powertrain control module (PCM). When the PCM receives the ground signal, it switches into the PERFORMANCE mode and the following changes occur:

^ Upshifts occur at a higher engine speed.
^ Downshifts occur at a lower percentage throttle position.
^ Engine torque output is increased in 2nd and 3rd gear.

Diagnostic Aids

^ Inspect the wiring at the PCM connector, the PERFORMANCE/ NORMAL switch connector and all other circuit connecting points for the following conditions:
- A backed out terminal
- A damaged terminal
- Reduced terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
^ Verify that any aftermarket electronic equipment is properly installed. Improperly installed aftermarket electronic equipment may modify the integrity of other systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step verifies that the Performance/Normal Switch is functioning properly.
3. This step determines if a condition exists in circuit 1550.