Component Tests: Tachometer

WARNING: This page is about a different car, the 2003 Lexus RX 300 and 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Reversing the connection of the tachometer will damage the transistors and diodes inside.

CAUTION: When removing or installing the tachometer, be careful not to drop or subject it to heavy shocks.

On-Vehicle Inspection - Connect a tune-up test tachometer and start the engine. Compare the tester and tachometer indications, DC 13.5 volts at 7°F (25°C). See INSPECTING TACHOMETER ON-VEHICLE table. If error is excessive, replace the tachometer. See COMBINATION METER under REMOVAL & INSTALLATION.

INSPECTING TACHOMETER ON-VEHICLE (RPM)

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

Resistance Inspection - Remove the meter cover, A/C and combination meter integrated ECU and combination meter circuit plate. See COMBINATION METER under REMOVAL & INSTALLATION. Measure the resistance between terminals with fixing pointer to the stopper. See CONNECTOR IDENTIFICATION . See INSPECTING SPEEDOMETER ASSEMBLY RESISTANCE table. If the resistance value is not as specified, replace the meter. See COMBINATION METER under REMOVAL & INSTALLATION.