Specifications

Symptom:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT PLAUSIBILITY
WITH ENGINE OIL SENSOR
When Monitored and Set Condition:
P0115-ENGINE COOLANT TEMP SENSOR CIRCUIT PLAUSIBILITY WITH EN-
GINE OIL SENSOR
When Monitored: With the engine running.
Set Condition: The ECT Sensor signal indicates a different engine temperature than the
EOS Sensor.
POSSIBLE CAUSES
CURRENT DTC
ECT SENSOR
ECT SENSOR - COLD
ECT SENSOR - HOT
ENGINE OIL SENSOR SENSOR
HGH RESISTANCE IN ECT SENSOR CIRCUITS
ENGINE COLD TOO LONG
TEST ACTION APPLICABILITY
1 Verify that the coolant level is correct.
Start the engine.
NOTE: The thermostat must be operating correctly for this test to be valid.
With the DRBIIIt, erase ECM DTCs.
With the DRBIIIt, set the engine RPM to 1500 and allow the engine to warm up for
10-15 minutes.
With the DRBIIIt, monitor the Engine Coolant Temperature value during the warm
up cycle. Make sure the transition of temperature change is smooth.
Did the engine temperature reach a minimum of 80° C (176° F)?
All
Yes → Go To 2
No → Refer to the Service Information for cooling system performance
diagnosis. The most probable cause is a Thermostat problem.
Also, refer to any related TSBs.
Perform ROAD TEST VERIFICATION - VER-2.
2 Turn the ignition on.
With the DRBIIIt, read the ECM DTCs.
Did this DTC return after performing the previous test?
All
Yes → Go To 3
No → Check for possible connecor or wiring problems at the ECT sensor
that may cause an intermittent problem. Repair as necessary.
Test Complete.
Perform ROAD TEST VERIFICATION - VER-2.
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DRIVEABILITY - DIESEL