Test No. 2: Speedometer 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:
Vehicle speed sensor signals originate from anti-lock brake system wheel speed sensors and is a shared output to various control units. Ensure anti-lock brake system and engine control system are operating properly and no diagnostic trouble codes are present. See SELF-DIAGNOSTICS - AVALON
article in ENGINE PERFORMANCE and appropriate ANTI-LOCK article in BRAKES.
- Using a speedometer tester, test drive vehicle and check speedometer for allowable error and also check function of odometer. Ensure tires are correct size and inflated properly. See SPEEDOMETER ALLOWABLE ERROR table. If vehicle speedometer readings are not within allowable range, replace speedometer.SPEEDOMETER ALLOWABLE ERROR
Standard Indication (MPH) Allowable Range (MPH) 20 18-24 40 38-44 60 58-66 80 78-88 100 98-110 120 118-132 - Check vehicle speed sensor. See VEHICLE SPEED SENSOR in SYSTEM & COMPONENT TESTING - V6 & V8 article in ENGINE PERFORMANCE. If vehicle speed sensor is okay, go to next step.
- 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 speedometer. See Fig 1. See SPEEDOMETER 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.SPEEDOMETER 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 instrument cluster ground circuit. Ground circuit is through Brown wire at 22-pin electrical harness connector C9 terminal A20. See INSTRUMENT CLUSTER in SYSTEM WIRING DIAGRAMS article. If ground circuit is faulty, repair and retest system. If ground circuit is okay, substitute original instrument cluster with a known-good unit and recheck system operation. If system operates properly, original instrument cluster was defective. If system still does not operate properly, perform instrument cluster pin voltage check. See INSTRUMENT CLUSTER under PIN VOLTAGE TESTS. Check wiring harness and electrical connectors for an intermittent problem. Repair wiring harnesses or connectors as necessary. If voltage values, harnesses and connectors are okay, replace instrument cluster. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .