Signal Too Low
Signal too low
Diagnostic trouble code (DTC) status, ECM-2000 Engine coolant temperature (ECT) sensor. Signal too low
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 wiring and component
No - Intermittent fault
-------------------------------------------------
Intermittent fault
Signal too low. Intermittent fault
Checking wiring and connectors
Check the signal cable between control module terminal #A40 and engine coolant temperature (ECT) sensor terminal 2. Check for an intermittent short-circuit to ground.
Other information
- To access the control module, see Engine control module (ECM), replacing Service and Repair
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- 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 - Fault-tracing information
------------------------
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
------------------------
Attempt New Test - Checking wiring and connectors
FAULT FOUND - DONE
DONE - DONE
-------------------------------------------------
DONE - DONE
-------------------------------------------------
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 [1][2]Coolant Temperature Sensor/Switch (For Computer).
Check the signal cable between control module connector terminal #A40 (#A40) and engine coolant temperature (ECT) sensor terminal 1. Check for an short-circuit to ground. Check for an open-circuit.
Check the ground lead between control module connector terminal #A61 (#B3) and engine coolant temperature (ECT) sensor connector 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 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
-------------------------------------------------
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 [1][2]Coolant Temperature Sensor/Switch (For Computer).
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
------------------------
VERIFICATION FAILED - Fault-tracing information
VERIFIED - Fault Found
-------------------------------------------------
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
------------------------
FAULT-TRACING FAILED - FAULT-TRACING FAILED
Attempt New Test - ECM-2000 Engine coolant temperature (ECT) sensor. Signal too low
-------------------------------------------------