| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION. |
Circuit Description
PNP switch sends a signal to ECM when transaxle is in Neutral or Park. This signal is used for air/fuel correction and for idle speed control. DTC is set when 2 or more switches are on simultaneously for "R", "N", "2" and "L" position, or ECM is receiving an ON signal from PNP switch when vehicle is being operated for more than 30 seconds at 50 MPH or more (2000-5000 RPM). Possible causes are
- PNP switch circuit is shorted.
- Defective PNP switch.
- Defective ECM.
Diagnostic Aids
Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.