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Home >> Audi >> 1985 >> 5000CD Turbo (Canada) L5-2144cc 2.14L SOHC Turbo (KH) >> Repair and Diagnosis >> Powertrain Management >> Relays and Modules - Powertrain Management >> Relays and Modules - Computers and Control Systems >> Engine Control Module >> Testing and Inspection >> Component Tests and General Diagnostics >> Tachometer Signal Test
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Tachometer Signal Test



Tachometer signal, checking
Work sequence





- Connect voltmeter between terminal 7 of control unit connector and ground

Note: This reading is made with connector attached to control unit. Gain access to terminals by pulling back connector boot
- Connect suitable tachometer to engine for measuring rpm
- Start engine and raise rpm to 2000
^ Specification: approx. 1.3 V

If specification NOT OK
- Replace control unit

If voltage reading OK, but vehicle tachometer does not correspond with testing tachometer
- Check wire between terminal 7 of control unit connector and vehicle tachometer according to current flow diagram. Repair as necessary.
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