For 1990-2009 cars only
Circuit Description
The vehicle speed sensor (VSS) information is communicated over the serial data circuit from the transmission control module (TCM). If the engine control module (ECM) does not detect the correct vehicle speed information, this DTC sets.
Conditions for Running the DTC
A combination of engine and transmission data parameters indicate that the engine is running and the vehicle is moving.
Conditions for Setting the DTC
The ECM receives no vehicle speed input or 5 seconds.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to DTC P0722 or DTC P0723 in Automatic Transmission |
