Fault-Tracing Information

Fault-tracing

Replacing thermostat

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

Engine control module (ECM) has registered that the actual temperature increase has deviated from the calculated temperature increase. This deviation is probably due to a damaged thermostat.
Check cables and connectors between engine control module (ECM) and engine temperature sensor for contact resistance and oxidation.
Remedy as necessary.

Other information
- Signal specification, B6304T4 Signal Specification, Engine Control Module (ECM)
- Thermostat, B6304T4 Service and Repair
- Engine coolant temperature sensor (ECT), B6304T4 Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals. Permanent Faults

Continue - Checking the status

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Checking the status




- Start the engine.
Check whether the fault is permanent or intermittent by reading off the signal from the engine coolant temperature (ECT) sensor. Check that the value is within its permitted range.
The fault is permanent if the value is not within its permitted range. Check that the value is within its permitted range.





Continue - Checking components and wiring

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Checking components and wiring








- Ignition off.
Check the engine coolant temperature (ECT) sensor. Check for contact resistance and oxidation.
Check the engine temperature sensor's resistance between #1 and #2 (against the sensor).
Remedy as necessary.

Other information
- Signal specification, B6304T4 Signal Specification, Engine Control Module (ECM)
- Connecting the breakout box, B6304T4 Breakout Box Connection, Engine Control Module (ECM)
- Component specifications, B6304T4 [1][2]Computers and Control Systems
- Checking wiring and terminals Checking Wiring and Terminals. Permanent Faults









Continue - Verification

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Verification




Verification

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








- Ignition off
- Reinstall the connectors, components etc.
- Ignition on
Read the engine temperature sensor signal by clicking the VCT2000 symbol.
Check that the signal corresponds with the engine temperature.





Does the signal correspond to the engine temperature?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - FAULT FOUND

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Fault-tracing information

Attempt New Test - Replacing thermostat

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