P0117

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is a thermistor that controls signal voltage to the Powertrain Control Module (PCM). When the engine is cold, the sensor resistance is high, therefore the PCM will see high signal voltage. As the engine warms, sensor resistance becomes less and voltage drops. The voltage measured across the thermistor is interpreted as a temperature. This is a type B DTC.

CONDITIONS FOR SETTING THE DTC
Engine coolant temperature greater than or equal to 151°C (304°F) for 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
- High idle
- No TCC
- Shift schedules will be affected.

CONDITIONS FOR CLEARING THE MIL/DTC
- The PCM will turn the MIL off after three consecutive trips without a fault condition.
- A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle.

DIAGNOSTIC AIDS
A vacuum leak or a pinched vacuum line may cause a DTC P0236. Check all vacuum lines and components connected to the hoses for leaks or sharp bends. Check vacuum source. A possible EGR DTC will store if there is a problem with the vacuum source. Also check for proper vacuum line routing. This diagnostic checks for a skewed sensor.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.

2. If the fault is still present, the engine coolant voltage will greater than 151°C (3O4°F).
3. This test simulates a DTC P0117. It the PCM recognizes the high signal voltage (low temperature) the PCM and the wiring are okay.