Test F: Tachometer Inaccurate
- Connect scan tool to DLC. Start engine. Using scan tool, access engine speed. If scan tool displays engine speed, go to next step. If scan tool does not display engine speed, repair engine speed signal circuit as necessary. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
- Using scan tool, perform instrument cluster LAMP and GAUGE SWEEP tests. If tachometer sweeps properly, check for intermittent poor connections. If tachometer does not sweep properly, replace instrument cluster.