Tachometer

Condition:

Tachometer (RPM):

- No diagnostic trouble codes (DTCs) stored for the engine speed (RPM) signal in the fuel/ignition system or combined instrument panel.

Possible Source:
- Defective tachometer.
- The combined instrument panel is programmed for a different scale than the tachometer.

Start fault-tracing with step 1, "Checking Tachometer", below.

1) Checking Tachometer:

- Connect Volvo Scan Tool (ST) to data link connector (DLC).

Engine Running:

- Start engine





- Go into scrolling values.
- Read off engine speed (RPM) at different engine speeds and compare with tachometer.
- Do engine speed (RPM) and tachometer agree?

Yes: No fault found.
No: Proceed to step 2, below.

2) Checking Programmed Engine Speed (RPM) for Tachometer:
- Read off and note maximum tachometer engine speed (RPM).

Ignition On:

- Ignition on.
- Volvo Scan Tool (ST) connected to data link connector (DLC).
- Go into "read combi" under "program combi".

VDO W/Turbo:

- Read off maximum tachometer engine speed (RPM).
- Does programmed engine speed (RPM) agree with maximum engine speed (RPM)?

Yes: Go to step 3, below.
No: Go to step 4, below.

3) Replacing Component:
- Try a new instrument panel.
- Then continue with step 5, below.

4) Programming Combined Instrument Panel:
- Program maximum tachometer engine speed (RPM) in the combined instrument panel. Diagnostic Functions
- Then continue with step 5, below.

5) Verification:

Note: After carrying out the repair check that the fault has been remedied.

- Ignition off.

Connect Connector:

- Reconnect connectors, reinstall components.

Engine Running:

- Start engine
- Go into scrolling values.





- Read off engine speed (RPM) at different engine speeds and compare with tachometer.
- Do engine speed (RPM) and tachometer agree?

Yes: Fault is corrected
No: The verification result shows that the fault persists. Do you want to quit fault-tracing?
Yes: Fault not corrected
No: Start over at step 1, above.