Short-circuit to Ground

Short-circuit to ground

Checking the function of the engine coolant temperature sensor




- Ignition on.
Read off the engine coolant temperature.
Check that the engine coolant temperature (ECT) reading is correct. Compare with the actual coolant temperature of the engine.





Is the temperature reading OK?

Yes - Checking components and wiring

No - Checking components and wiring

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Verification




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 off the engine coolant temperature.
Check that the engine coolant temperature (ECT) reading is correct. Compare with the actual coolant temperature of the engine.





Is the temperature within its permitted range?

Yes - VERIFIED

No - VERIFICATION FAILEDPAPER

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VERIFIED - Fault Found

VERIFICATION FAILED - 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 - FAULT-TRACING FAILED

No - Attempt New Test

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FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking the function of the engine coolant temperature sensor

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Checking components and wiring
- Check the resistance of the engine coolant temperature sensor
- Check the cable between combustion preheater module (CPM) terminal #4 and the ground terminal for the engine coolant temperature sensor. Check for a short-circuit to ground.

Hint: It is difficult to separate the ground lead for the engine coolant temperature sensor from the signal cable. Therefore, measure one cable at a time and see if plausible values are obtained from either of them.

Remedy as necessary.

Other information
- Connecting the breakout box Connecting the Breakout Box
- Signal specification Signal Specification
- For resistance values: Components resistance values Specifications
- Overheat protection thermostat / flame sensor / engine coolant temperature sensor, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals






Continue - Verification

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Checking components and wiring
- Check the combustion preheater module (CPM) connectors. Check for contact resistance and oxidation
- Check the cable between combustion preheater module (CPM) terminal #16 and the signal terminal for the engine coolant temperature sensor. Check for an intermittent short-circuit to ground.
Remedy as necessary.

Other information
- Connecting the breakout box Connecting the Breakout Box
- Signal specification Signal Specification
- For resistance values: Components resistance values Specifications
- Overheat protection thermostat / flame sensor / engine coolant temperature sensor, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals





Continue - Verification

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