Test G: Speedometer And/Or Odometer Inaccurate Or Inoperative
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 GMC Savana Special, 2001 GMC Savana Camper Special, 2001 GMC Savana, 2001 Chevrolet RV Cutaway, and 2001 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
- If Instrument Panel Cluster (IPC) diagnostic system check has been performed, go to next step. If IPC diagnostic system check has not been performed, go to INSTRUMENT PANEL CLUSTER DIAGNOSTIC SYSTEM CHECK .
- Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC), located below steering column. See Figure . Raise and support rear wheels. Start engine. Place transmission in Drive or third gear, if manual transmission. Using scan tool, monitor Vehicle Speed Sensor (VSS) parameter in PCM ENGINE DATA 1 data list. If VSS parameter does not match speedometer display, go to next step. If VSS parameter match speedometer display, check for intermittent and poor connections. Repair as necessary.
- On models with gasoline engines, check for open or high resistance in Dark Green/White wire between IPC harness connector terminal B14 and Powertrain Control Module (PCM) harness connector C2 terminal No. 50. See Figure and Figure . On models with diesel engines, check for open or high resistance in Dark Green/White wire between IPC harness connector terminal B14 and VSS Buffer harness connector terminal No. 15. See Figure and Figure . On all engines, if Dark Green wire is okay, go to next step. If Dark Green wire is not okay, repair as necessary. After repair, go to step 6 .
- Check IPC connector for intermittent and poor terminal contact. If terminal contact is okay, go to next step. If terminal contact is not okay, repair as necessary. After repair, go to step 6 .
- Replace IPC. After repair, go to next step.
- Operate system to verify fault no longer exists. If fault still exists, go to step 2 .