Circuit Description
DTC P0722 indicates no vehicle speed signal pulses are present on circuit 400 at the PCM. Vehicle speed values are provided by the vehicle speed sensor (VSS). The sensor is a permanent magnet (PM) generator mounted on the differential area of the transaxle converter housing. The PM generator produces a pulsing voltage whenever vehicle speed is above 5 km/h (3 mph). These pulses occur 16 times per each revolution of the differential housing and are translated to provide vehicle speed in miles per hour. The km/h (mph) value read on the scan tool TCM menu may very slightly from the ECM data or the speedometer.
Conditions for Setting the DTC
DTC P0722 is set when the PCM has detected the following conditions after starting from a stop:
| • | Vehicle speed equals 0. |
| • | Turbine speed is above 1,400 RPM. |
| • | Steady moderate throttle. |
| • | The speed ratio across the torque converter is greater than 700 RPM. |
| • | During a 1-2 upshift, the turbine speed pulls down by a 1 to 2 ratio. This diagnostic commands TCC off during a 1 to 2 shift. |
Test Description
Numbered steps below refer to steps on the trouble chart.
- This step verifies the problem is still present.
- This test indicates if a problem is a PCM or a wiring/sensor problem.
- An open or shorted sensor will set DTC P0722. This test indicates if a problem is a wiring problem or a faulty sensor.
- An open, ground, or a short to voltage in circuits 400 or 401 will cause DTC P0722 to set. This step indicates which circuit is faulty.
Repair Verification
Monitor the DTC menu Code Status for Pass Since Code Clear and Pass This Ignition Cycle. When both have passed, the repair is verified.
Criteria for pass: The output speed is greater than 21 km/h (13 mph) for greater than 0.5 seconds.
