Fig. 2.242. Connection diagram of the coolant temperature sensor with the ECU
Conditions for storing fault codes
The ECU stores the code P0116 and turns on the engine management system malfunction indicator lamp if the actual operating characteristic of the sensor is more than 20°C below the ECU mode curve (determined by the amount of fuel supplied, the ambient temperature and the engine operating time) for 0.2 seconds in two driving cycles. This code indicates an abnormal coolant temperature value supplied by the coolant temperature sensor or the ECU. The ECU sets the code P0117 and turns on the engine management system malfunction indicator lamp if the coolant temperature sensor supplies a temperature value below –45°C for 0.2 seconds in two driving cycles.
The ECU sets the code P0118 and turns on the engine management system malfunction indicator lamp if the coolant temperature sensor shows a temperature value above 140°C for 0.2 seconds in two driving cycles.
Note: The resistance of the coolant temperature sensor changes depending on the temperature as follows:
- 5900 Ohm at 0°C;
- 2500 Ohm at 20°C;
- 300 Ohm at 80°C.
Examination
Remove the coolant temperature sensor from the intake manifold.
Fig. 2.243. Checking the resistance of the coolant temperature sensor
Check the resistance of the sensor by immersing its sensitive element in hot water (Fig. 2.243).
If the resistance deviates from the norm, replace the sensor.
Installation
Apply LOCTITE 962T or equivalent sealant to the threaded portion of the sensor.
Install the coolant temperature sensor and tighten it to the specified torque.
Tightening torque of the coolant temperature sensor: 15–20 N·m.