4L60-E Automatic Transmission

ON-BOARD DIAGNOSTICS SYSTEM OPERATION

This vehicle is equipped with an extensive on-board diagnostic system which is capable of detecting and compensating for faults, alerting the operator of a fault and recording pertinent data during the failure. It is also capable of displaying information about current vehicle performance when a fault occurred. Refer to Vehicle On-Board Diagnostics, found under Computers and Control Systems testing. Computers and Control Systems

^ Always begin with the Diagnostic Circuit Check. A computer malfunction somewhere else may cause transmission related driveability problems.

^ Check for Diagnostic Trouble Codes (DTC'S) before beginning diagnostics. These should be repaired first.

^ Transmission solenoids (VCC, Shift "A" & "B") may be quickly checked by using the "Output Cycling" function of On-Board Diagnostics. The solenoids will be cycled "ON" and "OFF" and you can listen for the solenoid clicking.

^ The Status of the Transmission solenoids can be read during road test by reading the "Data Display" while in On-Board Diagnostics.

^ VCC Brake Switch may be tested with Switch Test E.7.1..




DIAGNOSTIC CODES THAT MAY SET:

^ Trouble code E024 indicates a problem with the vehicle speed sensor.

^ Trouble code E039 indicates a problem with the viscous converter clutch.

^ Trouble code E075 indicates a problem with the vehicle speed sensor signal.

^ Trouble code E091 indicates a problem with the park/neutral switch.

^ Trouble code E096 indicates torque converter overstress.