Signal Missing. Permanent Fault

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

If reading is OK:
^ Proceed to: Checking The Signal Cable section below.

If reading is incorrect:
^ Proceed to: Checking Main Fuse 7 section below.





Checking Main Fuse 7
- Ignition OFF.
- Check that main fuse 7 (11A/7) is intact.
- Is it intact?

Yes:
^ Proceed to: Checking 30-supply To Main Fuse section below.

No:
^ Check circuit after main fuse 7 for a short-circuit to ground.
^ For further information about the circuit after the fuse, see Wiring Diagram.
^ Proceed to: Verification section below.





Checking 30-supply To Main Fuse
- Ignition OFF.
- Connect a voltmeter between rear terminal pin on main fuse 7 (11A/7) fuse holder and ground.
- The voltmeter should read battery voltage.

If reading is OK:
^ Check cable between main fuse 7 and engine cooling fan relay connector A for an open-circuit.
^ Proceed to: Verification section below.

If reading is incorrect:
^ Check cable between battery positive terminal and main fuse 7 for an open-circuit.
^ Proceed to: Verification section below.





Checking The 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: Checking Engine Control Module Connector section below.





Checking Engine Control Module Connector
- Ignition OFF.
- Connectors A and B disconnected.
- Check engine control module connector for contact resistance and 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 cause of the diagnostic trouble code (DTC) has been loose connections in the engine control module connector.
^ 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.
^ 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.

It reading is OK:
^ Proceed to: Checking Engine Cooling Fan Relay section 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.
^ Proceed to: Verification section below.





Checking 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. Then continue with PPE8.

No:
^ The cause of the diagnostic trouble code has been loose connections in the engine cooling fan relay and/or control module connectors. Check connectors for contact resistance and oxidation and remedy.
^ 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 High And Low-speeds.
- The engine cooling fan should now work.

If reading is OK:
^ Fault corrected.

If reading is incorrect:
^ Proceed to: Fault-tracing Information section below.

Fault-tracing Information
The verification result shows that the fault persists.

- Do you want to exit fault-tracing?

Yes:
^ Fault not corrected.

No:
^ Proceed to: Checking Power Cable section above.