GM 25036751 Sensor, Intake Air Temperature

The Intake Manifold Temperature (IMT) sensor is a thermistor that measures the temperature of the air entering the engine. It has a high resistance at low temperatures and vice versa. The PCM supplies a 5-volt signal to the sensor and measures the voltage to calculate the incoming air temperature. The sensor signal is used to adjust spark timing based on air density.

If a coolant temperature sensor wire circuit provides a flawed reading it may signal Code 14 or Code 15 to need wiring repair or sensor to be changed. To remove the sensor, the locking tab on the connector should be released and the connector disconnected from the sensor, the screw of the sensor should be unscrewed very slowly. Lay hands on the coolant sensor delicately since normal impacts can interfere with the operation of the fuel injection system. To improve its anti leakage and anti corrosion capability, wind round some Teflon sealing tape around the threads of the new sensor before installing and finally tightening it. Cases where the Manifold Air Temperature (MAT) sensor fixed at the air cleaner housing will cause Code 23 or Code 25. To remove it, disconnect the wire harness and unscrew the sensor; to install it follow the inverse procedure. The Manifold Absolute Pressure (MAP) sensor monitors pressure fluctuations in the intake manifold due to load or speed of the engine; failure results to code 33 or code 34 and affects fuel supply and timing of the ignition. Exhaust oxygen sensor, installed in the exhaust manifold, controls oxygen content and assists ECM to modify the fuel mix. The presence of an open oxygen sensor triggers Code 13 while low and high voltage conditions trigger both Code 44 and Code 45, the symptoms of which can also be associated with fuel system problems. The Turbocharger Boost Control Solenoid is a solenoid located in the intercooler pipe and is controlled by the ECM with reference to boost pressure and engine speed; a faulty Turbocharger Boost Control Solenoid may cause Code 23 which can result in turbocharger lag and richness in fuel delivery. The Park/Neutral switch informs the ECM when the transaxle is in Park or Neutral, which affects Transaxle Converter Clutch and idle air control valve; if this switch is disconnected while driving, it will cause idle quality problems and false codes. The ECM is connected to the starter solenoid to monitor engine cranking while the A/C 'On' signal in turn helps the A/C selector switch position for change in idle speed. The vehicle speed sensor transmits a pulse voltage signal to the ECM and this is converted into miles per hour to control TCC system, the distributor incorporates signals to ECM concerning the rpm and crankshaft position of the engine.

To test the sensor, connect a digital ohmmeter and compare the resistance to the ambient air temperature. Heat the sensor slightly and observe the temperature and resistance. If the sensor does not meet specifications, it should be replaced.

The MAF sensor measures the quantity of air entering the engine.

A failure can trigger Codes 33, 34, 63, or 64.

Wrap the threads with Teflon sealing tape to prevent leakage and corrosion.

No, the sensor will need to be assembled once received

This sensor is a 3/"x18 NPTF