| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM connectors and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
The PNP switch sends a signal to ECM when transmission is in Neutral or Park. This signal is used for air/fuel correction and for idle speed control. DTC is set under the following condition
- ECM is receiving an ON signal from PNP switch when vehicle is being operated for more than 30 seconds at 50 MPH or more (2000-3000 RPM).
Possible causes are
- PNP switch short circuit.
- PNP switch.
- ECM.
Note. Toyota scan tool can be used to confirm PNP switch.