P0117

ENGINE COOLANT TEMPERATURE SENSOR





Fault Symptoms.
CHECK ENGINE lamp (MIL) on.
Impaired driveability. Engine
reluctant to start.

Conditions.
P0117
Engine temperature higher than 140°C for more than 1 second.

P0118
Engine temperature lower than -40°C for more than 1 second.

Diagnostic Help.
The performance of the temperature sensor can be ascertained with an ISAT scan tool.
- Connect the ISAT Scan Tool.
- Turn the ignition switch to the ON position.
- Select "READ FUNCTIONS".
- Select "COOLANT TEMPERATURE".

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

Check The Wiring.
Intermittent faults may occur as a result of temporary short circuits and breaks in the wiring. Jiggle the wiring at several points and in different directions to ascertain whether the wiring harness, including any connectors, is causing the trouble. Observe the multimeter, ISAT scan tool or test lamp while doing this.





Diagnostic Procedure.
1. Check the grounding of the temperature sensor
- Unplug the temperature sensor's 2-pin connector.
- Connect a test lamp to battery positive (B+) and pin 2.

The test lamp should light up.

Did the test lamp light up?
YES: Continue with point 2.
NO: Repair or replace the lead in question and proceed to point 3.





2. Check the control module's temperature sensor input
- Connect the ISAT Scan Tool.
- Turn the ignition switch to the ON position.
- Select "READ FUNCTIONS".
- Select "COOLANT TEMPERATURE".

The ISAT scan tool should show a reading of 5 V.
- Connect a jumper lead between pins 1 and 2 of the temperature sensor's connector.

The ISAT scan tool should show a reading of 0 V.

Are all readings OK?
YES: Change the temperature sensor and continue with point 3.
NO: Check the lead in question and repair or replace it if necessary. Then continue with point 3.





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

Has the diagnostic trouble code recurred?
YES: Proceed at "Before Replacing a Control Module". Component Tests and General Diagnostics
NO: The steps taken to rectify the fault were correct.