Test J: Tachometer Inoperative

Check tachometer signal. Turn key OFF. Verify that the instrument cluster connectors are secure. Remove the instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Leave the instrument cluster connected. Connect the Rotunda 88 Digital Multimeter (105-00053) or equivalent to measure engine speed. Turn key ON, engine running. Measure the voltage on terminal No. 6 of the instrument cluster connector C268 on the back of the instrument cluster at the specified engine speeds. See TACHOMETER VOLTAGE table. See WIRING DIAGRAMS . Are the voltages OK? If yes, go to next step. If no, check for open in Green/White wire to PCM.

TACHOMETER VOLTAGE

Engine Speed (RPM)	Voltage (Volts)
1000	1.69
1500	2.64
2000	3.44
2500	4.50
3000	5.22

Check instrument cover printed circuit. Turn key OFF. Disconnect and remove the instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Measure the resistance between the terminals at the back of the tachometer on the instrument cluster printed circuit and the instrument cluster connector C268 terminals on the instrument cluster. See TACHOMETER CONNECTOR TERMINALS RESISTANCE table. See WIRING DIAGRAMS . Are the resistance readings correct? If yes, replace tachometer. See TACHOMETER under REMOVAL & INSTALLATION. If no, replace instrument cluster printed circuit. See INSTRUMENT CLUSTER PRINTED CIRCUIT under REMOVAL & INSTALLATION.

TACHOMETER CONNECTOR TERMINALS RESISTANCE

Tachometer	Instrument Cluster Connector C268 Terminals	Resistance (Ohms)
B	No. 2	less than 5
G	No. 5	less than 5
S	No. 6	less than 5