P1115

Diagnostic Chart:

Wiring Diagram:

Temperature - Resistance Chart For Sensors:

The engine coolant temperature sensor (ECT) is a thermistor located in the lower coolant passage of the engine's cylinder head. When coolant temperature is cold the sensor has a high resistance, as temperature increases the resistance of the sensor decreases. The PCM provides a five volt signal to the coolant sensor, which is also connected to PCM ground. The PCM reads the voltage drop on the signal line to determine coolant temperature.

DTC PARAMETERS

DTC P0118 and P1115 will set if the ECT reads below -35°C (-31°F) when:
^ The engine has been running longer than four minutes.
^ DTC P1115 will set if the conditions are met for two seconds. P0118 will set after five seconds.

CAUTION: THE ECT SIGNAL IS CONTINUOUSLY CHECKED WHEN THE ENGINE IS RUNNING.

DIAGNOSTIC AIDS

When attempting to diagnose an intermittent problem, use the Scan tool to review malfunction history diagnostic information. The supplemental data can be used to duplicate a problem.

Check the tightness of the female terminal grip with a spare male terminal.

Start engine and observe ECT reading on Scan tool. Normal operation is for the ECT to rise smoothly to approximately 88°C (190°F), as thermostat opens then stabilizes.

Visually inspect ECT wires for damage. Wiggle wires while observing Scan tool ECT reading and watch for a sudden shift in temperature.

ECT may be compared to IAT temperature, with a Scan tool if engine has cooled overnight at ambient temperature. They should be within four degrees of each other with ignition On - engine Off.

CAUTION: TO AVOID THE DANGER OF BEING BURNED, DO NOT REMOVE THE COOLANT SURGE TANK CAP WHILE THE ENGINE, RADIATOR AND TANK ARE HOT. SCALDING FLUID AND STEAM CAN BE BLOWN OUT UNDER PRESSURE.

To verify coolant sensor integrity, install a thermometer in the coolant surge tank. With engine running and A/C Off, the temperature in the bottle and the Scan tool reading for ECT should be within 15°F of each other.

CAUTION: IF A DTC P0118 AND/OR P1115 IS ACTIVE, THE TEMPERATURE GAGE WILL READ HALF.

NOTE: A short to B+ on circuit 410 will cause damage to the sensor. If found to be shorted, test sensor for proper resistive value.

NOTE: If fused jumper (in test chart step) blows fuse, locate and repair short to B+ in circuit.