CI-124 Engine Speed (RPM) Signal

Condition:

Tachometer (RPM):

- The combined instrument panel registers a engine speed (RPM) signal that exceeds 300 Hz, corresponding to approx. 9,000 rpm.

Possible Source:
- Lose connections in signal cable/connectors.
- Signal cable insulation damaged.
- The signal cable is too close to a source of interference.
- High contact resistance.

Fault Symptom(s):
- Tachometer indicates too high a value.

Start fault-tracing with step 1, below.

1) Checking Other Diagnostic Trouble Codes (DTCs):

Ignition On:

- Ignition on.





- Read off diagnostic trouble codes (DTCs) in combined instrument panel.
- Is diagnostic trouble code (DTC) CI - 132 stored?

Yes: Go to step 2, below.
No: Go to step 3, below.

2) Diagnostic Trouble Code (DTC) CI-132 Stored:
- Fault-trace according to CI-132. CI-132 Engine Speed (RPM) Signal

3) Status Check:

Engine Running:

- Start engine.





- Go into scrolling values.
- Read off engine speed (RPM).
- Is the engine speed (RPM) within its permitted range?

Yes: Go to step 8, below.
No: Go to step 4, below.

4) Checking Cables and Terminals:









- Check combined instrument panel connector A, connector 24/130 and ignition/engine control module (ECM) connector for loose connections.
- Check cable between combined instrument panel # A11 and engine control module (ECM) # B21 for an intermittent open-circuit, an intermittent short-circuit to ground and an intermittent short-circuit to supply voltage.
- On cars with EZ 129K: Check cable between combined instrument panel # A11 and ignition control module (ICM) # B29 for an intermittent open-circuit, an intermittent short-circuit to ground and an intermittent short-circuit to supply voltage.
- To perform above stated checks, Intermittent Fault
- Was a fault detected in cables and terminals?

Yes: Go to step 6, below.
No: Go to step 5, below.

5) Checking for Interference:
- Check that the signal cable is not too close to sources of interferences such as electric motors, ignition cables and cell phone cables.
- Then continue with step 6, below.

6) 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).
- Is the engine speed (RPM) within its permitted range?

Yes: Fault corrected
No: Go to step 7, below.

7) Fault-Tracing Information:
- The verification result shows that the fault persists.
- Do you want to quit fault-tracing?

Yes: The fault is not corrected!
No: Start over at step 1, above.

8) Faulty Signal, Intermittent Fault:









- Check combined instrument panel connector A, connector 24/130 and ignition/engine control module (ECM) connector for loose connections.
- Check cable between combined instrument panel # A11 and engine control module (ECM) # B21 for an intermittent open-circuit, an intermittent short-circuit to ground and an intermittent short-circuit to supply voltage.
- On cars with EZ 129K: Check cable between combined instrument panel # A11 and ignition control module (ICM) # B29 for an intermittent open-circuit, an intermittent short-circuit to ground and an intermittent short-circuit to supply voltage.
- To perform above stated checks, Intermittent Fault
- Then continue with step 9, below.


9) Fault-Tracing Information:
- For intermittent faults fault-tracing is not followed by a verification because the fault is not present at this moment.
- If you want to repeat fault-tracing, start over at step 1, above.