System Test H: Speedometer Inaccurate
- Perform ON-DEMAND SELF-TEST. See MODULE COMMUNICATIONS NETWORK article. If vehicle passes, go to next step. If vehicle does not pass, repair data link circuit. See MODULE COMMUNICATIONS NETWORK article.
- Test-drive vehicle. Compare speed indicated on speedometer with speed indicated on NGS tester. If speed indications agree, see BRAKE SYSTEM - ANTI-LOCK article in BRAKES section for vehicle speed signal concern. If speed indications do not agree, replace EIC, then retest system.