GM Service Manual Online
For 1990-2009 cars only

Condition

Action

Engine idle speed too fast during NEUTRAL to range shift

Adjust to correct idle speed.

Faulty throttle sensor/circuit

Repair or replace the sensor or circuit.

Faulty or sticking bleed ball in 1-2-3-4 clutch piston housing

Repair the transmission.

Excessive clutch running clearance

Rebuild the transmission and adjust clearances.

Shift adaptives not converged

Refer to FastLearn Procedure.

Instrument panel tachometer incorrect

Repair or replace the tachometer.

Incorrectly calibrated electronic speedometer

Calibrate the electronic speedometer.

Faulty speed sensor/circuit

Repair the circuit or replace the speed sensor. Refer to the speed sensor DTCs.

Loose speed sensor

Tighten the speed sensor retaining bracket bolt. Refer to Speed Sensor Replacement.

Degraded fluid

Change the transmission fluid and filter. Refer to Automatic Transmission Fluid and Filter Replacement.

Incorrect fluid level

Correct the fluid level. Refer to Transmission Fluid Check.

Low main pressure

Repair the transmission.

Intermittent conditions

Inspect the wiring harnesses and connectors.

Loose or damaged speed gear

Tighten the output flange bolt or replace the speed gear.

Sticking valves in the control valve body

Overhaul the control valve body assembly.

Leaking pressure control solenoids

Repair or replace the pressure control solenoids.