Faulty Signal

ECM-200A ENGINE COOLANT TEMPERATURE (ECT) SENSOR
FAULTY SIGNAL

Diagnostic Trouble Code (DTC) status ECM-200A Engine Coolant Temperature (ECT) sensor. Faulty signal




Note! When Reading the Diagnostic Trouble Code (DTC) status, other stored Diagnostic Trouble Codes (DTCs) and their status will be listed.

Read 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) displayed as permanent?
Yes - Skip to "Checking Engine Coolant Temperature (ECT)"
No - Continue below.


Checking wiring and connectors



Check Engine Coolant Temperature (ECT) sensor for loose connections according to [1][2]Checking Wiring and Terminals. Intermittent Faults and contact resistance and oxidation according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Other information
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace the control module, Engine Control Module (ECM), Replacing
- To access/replace the engine coolant temperature (ECT) sensor, Thermostat/Temperature Sensor, Engine Coolant,Replacing
- For information about signals, Pinout Values and Diagnostic Parameters


Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
--Testing Complete--


Checking Engine Coolant Temperature (ECT)



- Fault-tracing must begin with cold engine (+20°C (68°F)) so that the Engine Coolant Temperature (ECT) sensor can be tested over as wide a temperature range as possible.
- Turn off climate control.
- Start the engine.

Read Engine Coolant Temperature (ECT).
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 - Continue below.
No - Skip to "Replacing Component (ECT)"


Checking thermostat



- Start the engine and run it until the Engine Coolant Temperature (ECT) reaches approximately 100°C (212°F).
- Activate engine cooling fan (FC) with engine running.
- Wait approximately 90 seconds and then shut-off engine cooling fan (FC).

Read Engine Coolant Temperature (ECT). If it is 85°C (185°F) or lower when the fan stops, the thermostat is defective.

Is Engine Coolant Temperature (ECT) 85°C (185°F) or lower?
Yes - Continue below.
No - Skip to "Fault-tracing information


Replacing Component (Thermostart)
Try a new thermostat.

Other information
- To access/replace the thermostat, Thermostat/Temperature Sensor, Engine Coolant,Replacing

Skip to "Verification"


Replacing Component (ECT)
Try a new engine coolant temperature (ECT) sensor.

Other information
- To access/replace the engine coolant temperature (ECT) sensor, Thermostat/Temperature Sensor, Engine Coolant,Replacing


Verification



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

- Ignition off.
- Reconnect connectors, reinstall components Verification must begin with cold engine (+20°C (68°F)) so that the Engine Coolant Temperature (ECT) sensor can be tested over as wide a temperature range as possible.
- Turn off climate control.
- Start the engine.

Read Engine Coolant Temperature (ECT).
Check that the Engine Coolant Temperature (ECT) is within its permitted range and corresponds with the engine warming up.

Is Engine Coolant Temperature (ECT) 85°C (185°F) or lower?
Yes - Testing Complete
No - Continue Below.


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.