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Engine speed

Engine speed

Output signal to main instrument display panel

Symptom of fault

Tachometer does not work.

Diagnostic procedure

1. Check the wiring




- Check the wiring between pin 58 of the Trionic control module and pin 6 of the main instrument display panel for continuity.



- Check the lead for open circuit and shorting.


Is the lead OK?

yes

Continue with point 2.


no

Rectify the fault.


2. Check the output signal



- Plug in the Trionic control module.



- Unplug the main instrument display panel's connector.



- Start the engine and run it at idling speed.



- Take a frequency reading across pin 6 of the connector and a good ground.


At idling speed, about 900 rpm, the frequency should be about 30 Hz.

Are the readings OK?

yes

Continue fault diagnosis as described in Service Manual 3:5 "Electrical system, main instrument display panel".


no

Proceed to .