Signal Missing. Permanent Fault

Checking Power Cable
- Ignition off.
- Disconnect connector A from the fan control (FC) relay.
- Connect a voltmeter between FC relay connector A (for engine control module (ECM)) and ground.
- The voltmeter should read battery voltage.

If reading is OK:
^ Proceed to test step below.

If reading is incorrect:
^ The between the starter motor and FC relay features an integrated fusible link. If there is an open-circuit in this, the probable cause is short-circuit to ground in the circuit. Check the FC relay and fan motor before replacing the. Check cable between starter motor and engine cooling fan relay terminal A1 for an open-circuit.
^ The proceed to Verification section below.





Checking Signal Cable
- Ignition off.
- Connector A disconnected.
- Disconnect engine cooling fan relay connector B.
- Ignition on.
- Connect a voltmeter between relay connector B terminal 1 (engine control module side) and ground.
- The voltmeter should read approx. 6 Volts.

If reading is OK:
^ Proceed to Checking Signal Cable, High Speed section below.

If reading is incorrect:
^ Proceed to test step below.





Checking The Engine Control Module Connector
- Ignition off.
- Connectors A and B disconnected.
- Check engine control module connector for contact resistance, oxidation and remedy.
- Engine control module connected.
- Ignition on.
- Connect a voltmeter between relay connector B terminal 1 (engine control module side) and ground.
- The voltmeter should read approx. 6 Volts.

If reading is OK:
^ The source of the diagnostic trouble code (DTC) is poor contact in the engine control module connector.
^ The proceed to Verification section below.

If reading is incorrect:
^ Check cable between engine cooling fan relay terminal B1 and engine control module # A7 for an open-circuit.
^ The proceed to Verification section below.





Checking Signal Cable, High Speed
- Ignition off.
- Connectors A and B disconnected.
- Ignition on.
- Connect a voltmeter between relay connector B terminal 2 (engine control module side) and ground.
- The voltmeter should read approx. 3 Volts.

If reading is OK:
^ Proceed to test step below.

If reading is incorrect:
^ Check cable between engine cooling fan relay connector B2 and engine control module # A22 for a short-circuit to ground.
^ The proceed to Verification section below.





Checking The Engine Cooling Fan Relay
- Ignition off.
- Connect connectors A and B to engine cooling fan relay.
- Start the engine and idle it.
- Read off diagnostic trouble code status message.
- Is the diagnostic trouble code still permanent?

Yes:
^ Try a new engine cooling fan relay.
^ The proceed to Verification section below.

No:
^ The diagnostic trouble code has been caused by poor contact in the engine cooling fan relay and/or the engine control module connector. Check connectors for contact resistance, oxidation and remedy.
^ The proceed to Verification section below.





Verification
- After carrying out the repair, check that the fault has been remedied as follows.
- Ignition off.
- Engine cooling fan relay and engine control module connected.
- Ignition on.
- Activate engine cooling fan.
- Check full and low-speeds.
- The fan should now work.

If reading is OK:
^ Fault corrected

If reading is incorrect:
^ Proceed to test step below.

Fault-tracing Information
- The verification result shows that the fault persists.
- Do you want to exit fault-tracing?

Yes:
^ Fault hot corrected

No:
^ Return to Checking Power Cable section above.