Chevrolet 12569240 Pressure Sensor

The coolant sensor is a thermistor and is a voltage that changes with temperature and a break in the circuit of this thermometer can cause Code 14 or Code 15 or a broken wire repair or replace the sensor. To uninstall the sensor, unlock it, disconnect the cable, and screw it out, albeit delicately for there is danger of causing some harm to the fuel injection system. Prior to the installation of the new sensor use Teflon sealing tape over the threads in order to avoid leakage and corrosion, to install undo this process in reversed manner. The Manifold Absolute Pressure (MAP) sensor measures intake manifold pressure changes and translates it to a voltage signal for the ECM to modulate the fuel flow and ignition timing; a bad one will produce Codes 33, 34, 63, or 64, and if diagnosed with a problem, the unit must be replaced. The second type of thermistor, also installed in the air cleaner housing is the Manifold Air Temperature (MAT) sensor that prompts the ECM to delay EGA until the MAT is 40-degrees F; failures are indicated by Code 23 or Code 25; removal involves unpin the connector and use a wrench. MAF sensor checks the quantity of air getting to the motor with a high frequency failure Code 33 and a low frequency failure or power loss setting Code 34 and may present Codes 44 or 45; replacement involves the removal of the connector then the clamps thus lifting it off the vehicle. This sensor migrates in the exhaust system and measures the oxygen content and sends signals to the ECM when necessary for the fuel mixture and when indicates a circuit problem with a code 13, 44 or 45. Throttle position sensor is found on the throttle body inlet or directly on the throttle shaft, and the voltage output is useful in programming of fuel delivery with reference to throttle angle; this can cause codes 21 or 22; if replacement is required then there is a detailed process provided. The Park/Neutral switch, also placed on the automatic transaxle, informs the ECM that it is in Park or Neutral and determines TCC, EGR, and IAC control; it should not be disconnected while driving to prevent idle quality problems and Code 24. The A/C On signal sends a message to the ECM that the A/C is turned on to enable it to correct the idle speed and any circuit diagnostics should be done with the help of a dealer. The VSS sends an intermittent voltage signal to ECM to sense the speed and the crank shaft sensor is used to sense the position of the engine in terms of rpm.