LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 101 (Instrument Panel - Analog) >> Symptom Tests >> Speedometer &/Or Odometer Inaccurate

Speedometer &/Or Odometer Inaccurate

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1999 Oldsmobile Bravada, 1999 GMC Sonoma, 1999 GMC Jimmy, 1999 GMC Envoy, and 1999 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform INSTRUMENT PANEL CLUSTER (IPC) SYSTEM CHECK  under SYSTEM TESTS. If entire IPC is inoperative, go to INSTRUMENT PANEL CLUSTER (IPC) INOPERATIVE  . If just speedometer is inaccurate or inoperative, go to next step.
  2. Turn ignition off. Connect scan tool to Data Link Connector (DLC), located under left side of dash. Raise and support vehicle. Start engine. Place shift lever in Drive position (automatic) or third gear (manual) and allow drive wheels to spin. Select VEHICLE SPEED parameter on scan tool. Compare vehicle speed displayed on scan tool with expected speed at which vehicle is being driven. If vehicle speed displayed on scan tool agrees with expected vehicle speed, go to next step. If vehicle speed displayed on scan tool does not agree with expected vehicle speed, go to step 5).
  3. Compare vehicle speed displayed on scan tool with speed displayed on speedometer. If vehicle speed displayed on scan tool is within 3 MPH of speed displayed on speedometer, problem is intermittent. Perform INSTRUMENT PANEL CLUSTER (IPC) SYSTEM CHECK  under SYSTEM TESTS. If vehicle speed displayed on scan tool is not within 3 MPH of speed displayed on speedometer, go to next step.
  4. Replace IPC. See INSTRUMENT PANEL CLUSTER (IPC)  under REMOVAL & INSTALLATION. Retest operation.
  5. Turn ignition off. Disconnect IPC connector. Remove instrument cluster as necessary for access to IPC connector. See INSTRUMENT PANEL CLUSTER (IPC)  under REMOVAL & INSTALLATION. Remove IPC connector comb. Connect DVOM set to AC volts scale between ground and IPC connector terminal A4 (Dark Green wire). See Figure . Start engine. Place shift lever in Drive position (automatic) or third gear (manual) and allow drive wheels to spin. If 3-5 volts AC exists, go to step 7). If 3-5 volts AC does not exist, go to next step.
  6. Check for open, poor connection or short to voltage in Dark Green wire between PCM/VCM and IPC connector terminal A4. See WIRING DIAGRAMS  . Repair as necessary and retest system operation. If circuit checks okay, go to next step.
  7. Go to SYMPTOMS (GASOLINE) in TROUBLE SHOOTING - NO CODES - TRUCKS article in ENGINE PERFORMANCE.
scientia non olet · About LEMON Manuals