Examination
1. With the ignition on, disconnect the wiring from the IAT sensor located on the intake manifold (see accompanying illustration). Using an ohmmeter, measure the resistance between the two terminals on the sensor. Sensor resistance depends on temperature (see accompanying table).
Temperature,°С | Resistance, Ohm |
-20 | 12 |
0 | 5 |
20 | 2 |
40 | 1 |
80 | 0.5 |
101 | 0.4 |
121 | 0.2 |
2. With the ignition on (do not start the engine) measure the reference voltage at the sensor wiring connector terminals (red-yellow wire) (see illustration above). The result of the measurement should be about 5 V, otherwise walk the wire to the ECM / PCM, checking it for breaks and fastening of the contact connections.
3. If the wiring is OK, replace the IAT sensor.
4. If replacing the sensor does not resolve the problem, the vehicle should be taken to a workshop to have the ECM/PCM diagnosed.
Replacement
1. Disconnect wiring from sensor (see illus. higher).
2. Turn out fixing screws and remove the gauge from the inlet pipeline.
3. Installation is carried out in the reverse order.