Test No. 3: Tachometer Does Not Operate

WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Tachometer signal is received from Engine Control Module and furnished to the multi-display information center and instrument cluster. Ensure engine control system is operating properly and no diagnostic trouble codes are present. See SELF-DIAGNOSTICS - AVALON article in ENGINE PERFORMANCE.

Using a tune-up test tachometer, start engine and check tachometer for allowable error. See TACHOMETER TEST table. If vehicle tachometer readings are not within allowable range, replace tachometer.

TACHOMETER TEST

Standard Indication (RPM)	Allowable Range (RPM)
700	630-770
1000	900-1100
2000	1850-2150
3000	2800-3200
4000	3800-4200
5000	4800-5200
6000	5750-6250
7000	6700-7300

Turn ignition off. Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Disconnect 22-pin electrical harness connector C9 and 18-pin electrical harness connector C10 from back side of instrument cluster. See Figure. Measure resistance across specified terminals of tachometer. See Figure. See TACHOMETER RESISTANCE table. If resistance is within specification, go to next step. If resistance is not within specification, replace instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION.

TACHOMETER RESISTANCE

Test Between Terminals	Specification (Ohms)
"A" & "B"	250
"C" & "D"	250

Check ECU-ACC (5-amp), ECU-B (7.5-amp), ECU-IG No. 2 (10-amp), GAUGE No. 1 (10-amp), PANEL (5-amp), and RADIO (15-amp) fuses in driver side junction block located under left side of instrument panel. See Figure. If fuses are okay, go to next step. If fuses are defective, repair short in wiring connected to identified fuse. See INSTRUMENT CLUSTER in SYSTEM WIRING DIAGRAMS article. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
Check multi-display information center and instrument cluster ground circuits. See INSTRUMENT CLUSTER in SYSTEM WIRING DIAGRAMS article. If ground circuits are faulty, repair and retest system. If ground circuits are okay, substitute original multi-display information center or instrument cluster with a known-good unit and recheck system operation. If system operates properly, original multi-display information center or instrument cluster was defective. If system still does not operate properly, perform multi-display information center, instrument cluster and instrument cluster/multi-display information center electrical harness pin voltage checks. See MULTI-DISPLAY INFORMATION CENTER , INSTRUMENT CLUSTER and INSTRUMENT CLUSTER/MULTI-DISPLAY INFORMATION CENTER ELECTRICAL HARNESS under PIN VOLTAGE TESTS. Check wiring harnesses and electrical connectors for an intermittent problem. Repair wiring harnesses or connectors as necessary. If voltage values, harnesses and connectors are okay, replace multi-display information center and/or instrument cluster. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .