Tachometer Not Working

Tachometer Not Working

Fault symptoms
Tachometer not working.

Diagnostic help
The gauge can be activated using the diagnostic instrument.

Information on the engine speed is sent out on the bus from Trionic and can be read by the diagnostic tool.

Checking the wiring harness
Jiggle the leads and in-line connectors at various points and in different directions to detect any intermittent breaks or short circuits in the wiring. Observe the multimeter, test lamp or diagnostic instrument while carrying out this check.

Diagnostic procedure

1. Checking the engine speed
^ Connect the diagnostic instrument and contact the Main instrument unit.
^ Read the engine speed.





Is the value reasonable?
YES
^ Go to step 2.
NO
^ See fault diagnosis in Computers and Control Systems.

2. Final check
^ Clear diagnostic trouble codes in all Systems.





^ Carry out a function check





Is the function correct?
YES
^ The steps taken to rectify the fault were correct.
NO
^ See Fault diagnosis, general, "Before changing a control module." Before Changing A Control Module