Faulty Signal

Faulty signal

Checking the component

Warning! The engine cooling fan (FC) can also operate if the ignition is switched off when this diagnostic trouble code (DTC) is stored.

Hint: To avoid injury, disconnect the power supply to the engine cooling fan (FC) during fault-tracing.

- Check the connector on the engine coolant temperature (ECT) sensor. Check for contact resistance and oxidation.

Hint: This diagnostic trouble code (DTC) is stored if the engine coolant temperature (ECT) sensor freezes. This may happen if the coolant level is low or there is too little glycol in the coolant. Check the engine coolant level and its freezing point.

Remedy as necessary.

Other information
- Connecting the breakout box, B5254T7 Connecting The Breakout Box, Engine Control Module (ECM)
- Signal specification, B5254T7 Signal Specification, Engine Control Module (ECM)
- Component specifications, B5254T7 Specifications
- Engine coolant temperature sensor (ECT), B5254T7 Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals









Continue - Verification

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Verification




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








- Verification should begin with a cold engine (+20 °C) so that the engine coolant temperature (ECT) sensor can be tested over as wide a temperature range as possible
- Ignition off
- Reconnect the connectors, reinstall components etc.
- Start the engine.
Read off the engine coolant temperature (ECT) sensor signal.
Check that the engine coolant temperature (ECT) is within its permitted range and corresponds with the engine warming up.





Is the temperature within its permitted range?

Yes - Troubleshooting procedure complete

No - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - Exit Fault-Tracing

No - Attempt New Test

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Attempt New Test - Checking the component

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