DTC Advanced Diagnostics: P0117
DTC P0117:Engine Coolant Temperature (ECT) Sensor 1 Circuit Low Voltage (Engine Type: J35Y1, J35Y2)

General Description


Engine coolant temperature (ECT) sensor 1 is used for air/fuel ratio feedback control, ignition timing control, idle speed control, and other functions. The ECT sensor 1 resistance varies depending on the engine coolant temperature. As the engine coolant cools, the ECT sensor 1 resistance increases, and the powertrain control module (PCM) detects a high signal voltage. As the engine coolant warms, the ECT sensor 1 resistance decreases, and the PCM detects a low signal voltage. If the ECT sensor 1 output voltage is a set value, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status
Execution
Continuous
Sequence
None
Duration
2 seconds or more
DTC Type
One drive cycle, MIL on
OBD Status
PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions
Condition
 
Engine start/stop button
ON mode
No active DTCs set (prevents monitor from running)
P0118

Malfunction Threshold
The ECT sensor 1 output voltage [ECT SENSOR 1] is 0.08 V or less for at least 2 seconds.

[ ]: HDS Parameter

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
ECT sensor 1 TW line short to ground
ECT sensor 1 failure
PCM internal circuit failure

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.