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P0117,P0118

Symptom: CHECK ENGINE lamp (MIL) on. Impaired driveability. Engine reluctant to start. Any other diagnostic trouble codes (misfiring).

P0117 , P0118

Coolant temperature sensor

Fault symptoms

CHECK ENGINE lamp (MIL) on. Impaired driveability. Engine reluctant to start. Any other diagnostic trouble codes (misfiring).

Conditions

P0117 Shorting to ground.

P0118 Shorting to battery positive (B+)/open circuit

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.

- Turn the ignition switch to the ON position.

- Connect the test lamp to:


The test lamp should light up.

Did the test lamp light up?

yes

Continue with point 2.


no

Repair or replace the appropriate lead. Continue with 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 both readings OK?

yes

Change the temperature sensor, continue with point 3.


no

Check the relevant lead and repair or replace it if necessary. Continue with point 3.


3. Final check



- Clear the diagnostic trouble code.

- Implementation of driving cycle:

- Evaluation of driving cycle:


Has the diagnostic trouble code recurred?

yes

Continue as described in .


no

The steps taken to rectify the fault were correct.