Component Testing: Tachometer
NOTE:
DO NOT
allow engine speed to exceed allowable range, engine could be damaged.
- Connect New Generation Star (NGS) Scan Tool (49-T088-0A0) to battery and to Data Link Connector (DLC) located under left side of instrument cluster, near steering column. Using NGS scan tool, select VEHICLE & ENGINE SELECTION, and enter vehicle specifications.
- Using NGS scan tool, select PID/DATA MONITOR AND RECORD, and then select PCM - POWERTRAIN CTRL MODULE. Select RPM, and then press START. Verify tachometer is within allowable range. See TACHOMETER VARIATION SPECIFICATIONS . If tachometer is not within allowable range, check engine speed signal transmitter (ECM/PCM) and related wiring harness. If engine speed signal transmitter (ECM/PCM) and related wiring harness are okay, replace tachometer.