Fault-Tracing Information

Engine Speed Dips When A Gear Is Selected (Automatic Transmission)

Trouble Code Condition(s)
- Diagnostic trouble codes (DTCs) absent.
- Engine is hot.
- Fault is permanent.

Possible source(s)
- Open-circuit in AW 50-42 transmission control module (TCM) signal cable.
- Short-circuit to ground or supply voltage in signal cable.
- Contact resistance in connectors
- Defective gear selector or idle air control (IAC) valve.

^ To start fault-tracing proceed to Checking Signal From the Transmission Control Module section.