Note. DTC applies only to A/T models.
| CAUTION | If ECM replacement is instructed in following tests, always ensure ECM connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. |
Note. For component location, see appropriate illustration in THEORY & OPERATION article.
Circuit Description
Park/Neutral Position (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 when 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 Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.