Tachometer Malfunctioning
- Using scan tool, monitor PCM. If ENGINE RPM signal is correct, go to next step. If ENGINE RPM signal is incorrect, see appropriate BASIC TESTING article in ENGINE PERFORMANCE section.
- Using scan tool, monitor BFC SPI serial data bus. If tachometer input is active, replace instrument cluster. See INSTRUMENT PANEL article. If tachometer input is not active, check for short to ground in White wire between PCM and instrument cluster. Repair as necessary.