DTC Troubleshooting: P0118
DTC P0118: ECT Sensor 1 Circuit High Voltage
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0118 ECT Sensor 1 Circuit High Voltage
     

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
ECT SENSOR 1
More than 4.92
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
2.
ECT sensor 1 check:

ECT sensor 1 check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
ECT sensor 1 2P connector

?3.
Connect terminals A and B with a jumper wire.
Terminal A
ECT sensor 1 2P connector No. 1
Terminal B
ECT sensor 1 2P connector No. 2


?4.
Turn the vehicle to the ON mode.

?5.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
ECT SENSOR 1
More than 4.92
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
3.
Determine possible failure area (TW line, others):

Determine possible failure area (TW line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Remove the jumper wire from the ECT sensor 1 2P connector.

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
ECT sensor 1 2P connector: disconnected
Test point 1
ECT sensor 1 2P connector No. 2
Test point 2
Body ground


Is there about 5.0 V?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Go to step 5.
4.
Open wire check (SG2 line):

Open wire check (SG2 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connector.
PCM connector C (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
ECT sensor 1 2P connector: disconnected
 
PCM connector C (51P): disconnected
Test circuit
SG2
Test point 1
ECT sensor 1 2P connector No. 1
Test point 2
PCM connector C (51P) No. 31


Is there continuity?

     
YES
     
     
     
The SG2 wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0118 goes away and the PCM was updated, troubleshooting is complete. If DTC P0118 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the SG2 wire between the PCM (C31) and ECT sensor 1.?
5.
Open wire check (TW line):

Open wire check (TW line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connector.
PCM connector B (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
ECT sensor 1 2P connector: disconnected
 
PCM connector B (51P): disconnected
Test point 1
ECT sensor 1 2P connector No. 2
Test point 2
PCM connector B (51P) No. 50


Is there continuity?

     
YES
     
     
     
The TW wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0118 goes away and the PCM was updated, troubleshooting is complete. If DTC P0118 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the TW wire between the PCM (B50) and ECT sensor 1.?