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Signal Too High






Signal too high

Diagnostic trouble code (DTC) status, ECM-2000 Engine coolant temperature (ECT) sensor. Signal too high

Reading off diagnostic trouble code (DTC) status ECM-2000
Note! When reading off the diagnostic trouble code (DTC) status, other stored diagnostic trouble codes (DTCs) and their status will be listed.

- Read off the diagnostic trouble code (DTC) status. Check the status of the relevant diagnostic trouble code (DTC).





Was the status of the relevant diagnostic trouble code (DTC) permanent?

Yes - Checking the connector

No - Intermittent fault

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Intermittent fault





Signal too high. Intermittent fault

Checking wiring and connectors
Check the signal cable between control module terminal #A40 and terminal 1 on the connector for the engine coolant temperature (ECT) sensor. Check for an intermittent open-circuit. Check for an intermittent short-circuit to supply voltage.

Hint: With the ignition on and the engine coolant temperature (ECT) sensor connector disconnected, the voltage between terminal 1 and the ground terminal must be approximately 5 V.

Check the ground lead between control module terminal #A61 and terminal 2 on the connector for the engine coolant temperature (ECT) sensor. Check for an intermittent open-circuit.

Other information
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access the control module, see Engine control module (ECM), replacing Service and Repair
- To access the engine coolant temperature (ECT) sensor, see Engine coolant temperature (ECT) sensor, replacing Service and Repair
- For information about signals, see Signal specification Signal Description / Specification
- Checking wiring and terminals Checking Wiring And Terminals.










Continue - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

Do you want to view the information again?

Yes - Attempt New Test

No - Fault Found

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Attempt New Test - Checking wiring and connectors

FAULT FOUND - DONE

DONE - DONE

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DONE - DONE

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Checking the connector




- Ignition off
- Check the connector on the engine coolant temperature (ECT) sensor. Check for contact resistance and oxidation.
Remedy as necessary.

Other information
- To access or replace the engine coolant temperature (ECT) sensor, see Engine coolant temperature (ECT) sensor, replacing Service and Repair
- For information about signals see Signal specification Signal Description / Specification
- Checking wiring and terminals Checking Wiring And Terminals.






Continue - Checking the connector

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Checking the connector








- Ignition off
- Reinstall the components, reconnect the connectors etc.
- Ignition on
- Read off the engine coolant temperature (ECT) sensor signal.
Check that the signal is within its permitted range - compare with the value in the table: Engine coolant temperature (ECT) sensor Specifications.
If the temperature reading is now OK, the fault was probably caused by poor contact in the connector.

Other information
- To access or replace the engine coolant temperature (ECT) sensor, see Engine coolant temperature (ECT) sensor, replacing Service and Repair
- For information about signals, see Signal specification Signal Description / Specification.





Is the temperature reading OK?

Yes - Verification

No - Checking the wiring and component

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Checking the wiring and component
Check the resistance of the engine coolant temperature (ECT) sensor. For the resistance values, see Engine coolant temperature (ECT) sensor Specifications.
Check the signal cable between control module connector terminal #A40 (#A40) and engine coolant temperature (ECT) sensor terminal 1. Check for an open-circuit. Check for a short-circuit to supply voltage.

Hint: With the ignition on and the engine coolant temperature (ECT) sensor connector disconnected, the voltage between terminal 1 and the ground terminal must be approximately 5 V.

Check the ground lead between control module connector terminal #A61 (#B3) and engine coolant temperature (ECT) sensor terminal 2. Check for an open-circuit.
Remedy as necessary.

Other information
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access or replace the control module, see Engine control module (ECM), replacing Service and Repair
- To access or replace the engine coolant temperature (ECT) sensor, see Engine coolant temperature (ECT) sensor, replacing Service and Repair
- For information about signals, see Signal specification Signal Description / Specification
- Checking wiring and terminals Checking Wiring And Terminals.










Continue - Verification

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Verification




Verification

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








- Ignition off.
- Reconnect connectors, reinstall components.
- Start the engine and let it idle.
- Read off engine coolant temperature (ECT) sensor signal.
Compare the engine coolant temperature (ECT) sensor signal with the table value according to: Engine coolant temperature (ECT) sensor Specifications.
Let the engine run at idling speed, check that the signal sinks when the engine warms up.





Is the engine coolant temperature (ECT) sensor signal OK?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - Fault Found

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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 - ECM-2000 Engine coolant temperature (ECT) sensor. Signal too high

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