P0115

P0115
ECT Sensor signal implausible.

P0117
ECT Engine Coolant Temperature - Malfunction.

P0118
ECT Engine Coolant Temperature - Above Upper limit.

Function:
The ECT sensor measures the engine temperature by means of a variable resistor.
The engine coolant temperature is required for control of the warm-up phase. In the event of a fault, a calculated substitute characteristic is used.

Diagnostic Conditions:

P0115
60 seconds after engine start-up, load interruption. A fault is recorded after a debounce time of 0.4 seconds if the measured engine temperature is lower than the calculated engine temperature minus approx. 10°C.

P0117
A fault is recorded after a debounce time of 0.4 seconds if an engine temperature of less than -42°C is measured.

P0118
A fault is recorded after a debounce time of 0.4 seconds if an engine temperature of more than 140°C is measured.

Wiring Diagram



Resistance Values:
0°C = 5.0 - 7.0 k Ohms
20°C = 2.0 - 3.0 k Ohms
60°C = 0.4 - 0.8 k Ohms

Diagnostic Procedure:




P0115




P0117




P0118


1. Check ECT (NTC II) sensor.
1. Remove connector in the engine compartment.
2. Connect ohmmeter to ECT (NTC II) sensor connector, pins 1 and 4.

Specified Value: 2 - 3 k Ohms at 20°C.

2. Check Output Voltage of ECM.
1. Connect special tool 9616.
2. Connect voltmeter to pin 74 (plus) and 34 (minus).
3. Ignition on.

Specific Value: approx. 5 V.

3. Check wiring from ECM to ECT (NTC II) sensor for continuity.
1. Connect special tool 9616 to wiring harness.
2. Remove connector for ECT (NTC II) sensor.
3. Connect ohmmeter to special tool 9616, pin 34, and temperature sensor connector, pin 4.

Specified Value: 0 - 5 Ohms.

4. Connect ohmmeter to special tool 9616, pin 74, and temperature sensor connector, pin 1.

Specified Value: 0 - 5 Ohms.

4. Check wiring between ECM and ECT (NTC II) sensor for short circuit to ground.
1. Connect special tool 9616 to wiring harness.
2. Remove connector for ECT (NTC II) sensor.
3. Connect ohmmeter to special tool 9616, pin 74, and to ground.

Specified Value: Infinity Ohms.

If meter reads 0 - 5 Ohms, check wiring harness for chafing and pinching damage.

5. Check wiring from ECM to ECT (NTC II) sensor for short circuit to B+.
1. Connect special tool 9616.
2. Remove connector for ECT (NTC II) sensor.
3. Connect voltmeter to pin 74 (plus) and to ground.
4. Switch ignition on.

Specified Value: approx. 5 Volt.

If battery positive voltage is displayed, check wiring harness for chafing and pinching damage.