P0117

ENGINE COOLANT TEMPERATURE SENSOR





Symptom Of Fault.
The CHECK ENGINE lamp (MIL) is on.
Impaired driveability.
Reluctant to start.
Any other diagnostic trouble codes (misfiring)

Conditions.
P0115: All-embracing DTC
P0117: Ignition switch in the ON position: <0.08 V for 5 seconds.
P0118: Ignition switch in the ON position: >4.8 V for 5 seconds.

Diagnostic Help.
The temperature sensor reading can be obtained on an ISAT scan tool.

- Turn the ignition switch to the ON position and then back to the OFF position.
- Connect an ISAT scan tool.
- Select "READ FUNCTIONS".
- Select"COOLANT TEMP".

If the temperature sensor is in perfect working order the ISAT scan tool should show the current coolant temperature.

Checking The Wiring
Intermittent faults may occur as a result of occasional short circuits and breaks in the wiring. Jiggle the leads and in-line connectors at several places and in different directions to reveal faults in the wiring harness. Observe the multimeter, ISAT scan tool or test lamp while carrying out this check.





Diagnostic Procedure.
1. Check the temperature sensor's grounding

- Unplug the temperature sensor's 2-pin connector.
- Connect the test lamp to: Battery positive (B+) and pin 2.

The test lamp should light up.

Is the test lamp on?
YES: Continue with point 2.
NO: Rectify the lead in question and proceed to point 3.





2. Check the engine control module's temperature sensor input

- Turn the ignition switch to the ON position and then back to the OFF position.
- Unplug the temperature sensor's 2-pin connector.
- Connect an ISAT scan tool.
- Select "READ FUNCTIONS".
- Select "COOLANT TEMP".

The reading obtained on the ISAT scan tool should be about -40 °C (-40 °F).

- Connect a jumper lead between pins 2 and 1 of the temperature sensor connector.

The reading obtained on the ISAT scan tool should be about +127°C (261°F).

Are all readings OK?
YES: Change the temperature sensor and continue with point 3.
NO: Rectify the lead in question and proceed to point 3.





3. Final check:

- Clear the diagnostic trouble code.
- Implementation of driving cycle:
Drive the car at varying loads and engine rpm for 5 minutes.
- Evaluation of driving cycle:
Check whether the diagnostic trouble code has recurred.

Has the diagnostic trouble code recurred?
YES: Continue at "Before Replacing a Control Module. Component Tests and General Diagnostics
NO: The remedial measure taken was correct.