Examination
1. On 4-cylinder engines, disconnect the connector from the sensor, which is located inside the air filter, check the resistance of the sensor at various temperatures (See table Resistance Values for Healthy Intake Air and Coolant Temperature Sensors at Various Temperatures on 4-Cylinder Engines), blowing on the sensor, e.g. with a hairdryer. If the sensor resistance changes disproportionately with temperature, it should be replaced.
2. On 6-cylinder engines, disconnect the connector from the sensor, check the resistance of the sensor at different temperatures by connecting an ohmmeter to terminals 4 and 5 of the sensor, and compare with the table (see table Resistance values of healthy intake air and coolant temperature sensors at various temperatures on 6-cylinder engines). If the resistance of the sensor does not correspond to the table, then it should be replaced.
Resistance values of serviceable intake air and coolant temperature sensors at various temperatures on 4-cylinder engines
Temperature,°С | Resistance, Ohm |
100 | 125 |
90 | 250 |
80 | 300 |
70 | 400 |
60 | 500 |
50 | 625 |
45 | 750 |
40 | 875 |
35 | 1000 |
30 | 1500 |
25 | 2000 |
20 | 2500 |
15 | 3000 |
10 | 3500 |
4,5 | 4000 |
0 | 4500 |
Resistance values of serviceable intake air and coolant temperature sensors at various temperatures on 6-cylinder engines
Contact | Resistance, Ohm | Temperature,°С |
5 – 4 | 13,6 – 18,4 | –20 |
5 – 4 | 2,21 – 2,69 | 20 |
5 – 4 | 0,49 – 0,67 | 60 |
Replacement (4-cylinder engines)
Attention! On 6-cylinder engines, the IAT sensor is made in a single module with the air flow sensor.
1. Switch off the ignition.
2. Disconnect the connector and remove the sensor.