P0722

Diagnostic Chart:

Schematic:

The Vehicle Speed Sensor (VSS) produces an AC voltage of different amplitude and frequency depending on the velocity of the output shaft. The VSS produces the signal from 16 evenly spaced machined notches on the transaxle differential carrier. The vehicle speed sensor produces a readable AC voltage signal when vehicle speed is above 5 km/h (3 mph). This VSS signal is sent to the PCM, which is used to determine output shaft RPM. DTC P0722 sets when the PCM does not detect a VSS signal for a certain length of time.

DTC PARAMETERS
DTC P0722 will set if no VSS signal is detected when:
- Condition exists twice in one ignition cycle
- Vehicle is started from a stop
- Transaxle is in a forward gear
- Transmission ISS is greater than 1400 RPM
- Ratio of transmission ISS RPM to engine speed RPM is less than 0.78
- TP angle change is less than 11% for a minimum of 1.5 seconds
- DTC P0716 or P0717 is not active

DTC P0722 diagnostic runs continuously once the above conditions have been met.

DTC P0722 is a type A DTC

DIAGNOSTIC AIDS
To locate an intermittent problem, use Scan tool to monitor VEHICLE SPEED with vehicle raised and drive wheels moving greater than 5 km/h (3 mph). Wiggling wires while watching for a change in VEHICLE SPEED may locate a problem.

Check connection and sensor for tightness.

An intermittent open anywhere in the VSS circuit or intermittent short to ground/short to voltage on circuit 401 will cause the VEHICLE SPEED parameter on Scan tool to momentarily drop out.

If no VSS signal is received, the speedometer will be inoperative.

If the PCM does not receive a VSS signal, it will calculate a VSS signal value based on RPM and TP angle. The speedometer will still be inoperative, however.

VSS resistance: 800 - 1600 ohms