LEMON Manuals: Even more car manuals for everyone
Home >> Saturn >> 1997 >> SW2 Automatic >> Repair and Diagnosis (Single Page) >> Transmission >> Automatic Trans >> Diagnosis - Mp6 & Mp7 >> Diagnostic Testing >> DTC P0721: Vehicle Speed Sensor Signal Noise >> Diagnostic Procedure

Diagnostic Procedure

  1. Using scan tool, select TRANSAXLE GENERAL INFORMATION table. View vehicle speed noise. Raise and support front wheels at lower control arms. Start and run engine in Drive. Ensure vehicle speed is present. Wiggle PCM connectors. Repair connections as needed if VSS noise changes.
  2. Tap outside case of PCM with handle of screwdriver. If VSS noise value changes, replace PCM.
  3. Turn ignition off. Inspect PCM and VSS connectors and terminals. Repair as needed. If none of the following steps have found any problems, check for: secondary ignition input to VSS, VSS loose, intermittent VSS malfunction, intermittent PCM malfunction and intermittent open, short or ground in circuits between TSS and PCM.
scientia non olet · About LEMON Manuals