GM 12569240 Sensor,Map

You can Select Your Vehicle to check if 12569240 fits your vehicle.

The Manifold Absolute Pressure (MAP) sensor monitors the intake manifold pressure changes resulting from changes in engine load and speed and converts the information into a voltage output. The ECM/PCM receives information as a varying voltage signal from closed throttle (high vacuum) to wide open throttle (low vacuum). The ECM/PCM uses the MAP sensor to control fuel delivery and ignition timing. Performing the following test will set a diagnostic trouble code and illuminate the Service Engine Soon light. Clear the diagnostic trouble code after performing the tests and making the necessary repairs. The MAP sensor is located on the upper intake manifold plenum. Check the terminals in the connector and the wires leading to the sensor for looseness and breaks. Repair as required. Before checking the MAP sensor, check the voltage supply and ground circuits from the ECM/PCM. Disconnect the electrical connector from the MAP sensor and connect the positive lead of a voltmeter to the gray wire terminal (and the negative lead to the orange/black or black wire terminal at the harness connector. Turn the ignition key On-the voltage should read approximately 5.0 volts. If the voltage is incorrect, check the wiring from the MAP sensor to the ECM/PCM. If the circuits are good, have the ECM/PCM checked at a dealer service department or other properly equipped repair facility. To check the MAP sensor operation, reconnect the connector to the MAP sensor and using a suitable probe, back probe the light green wire terminal of the MAP sensor connector. Connect the positive lead of a voltmeter to the probe and the negative lead to a good engine ground point. Turn the ignition key On-with the engine not running the voltage should read 4.0 to 5.0 volts. Start the engine and allow it to idle. The voltage should decrease to approximately 0.5 to 2.0 volts. If the test results are incorrect, replace the MAP sensor. Access the MAP sensor. On TBI systems, remove the air cleaner assembly. On Central SFI systems, remove the intake air duct and resonator from the throttle body. On MPFI systems, remove the upper intake manifold from the engine. Disconnect the electrical connector from the MAP sensor. Remove the retaining bolts and draw the MAP sensor. Replace the MAP sensor seal in the upper intake manifold, if equipped. Installation is the reverse of removal.

While making checks, do so using a high-impedance, 10-megohm digital multimeter, to avoid destroying the PCM. On models featuring an anti theft audio system, turn off the anti theft system prior to disconnecting the battery or interrupting the battery supply to the stereo. In certain cases, after the Check Procedure, a trouble code is set, so, to erase all the codes in the PCM, remove the PCM-B fuse or disconnect the cable from the negative terminal on the battery for thirty seconds. In some instances, it might be relevant to employ pins or straightened paperclips to backprobe on the sensor electrical connector cables; always turning special attention not to short the probes. The A/C compressor clutch is managed by the PCM; the clutch will not engage until the engine idle speed is raised due to the load applied. Verify that your battery voltage at the a/c clutch with ign on, a/c on; if there is no battery voltage then check the fusable link and wires for damage. In the event you find that the fuse is all right, you should attempt to find voltage to the A/C compressor clutch relay. The camshaft position sensor under the distributor cap relays cylinder identification to the PCM and is not part of the ignition system. Check to see if the sensor is getting battery voltage at the harness connector if not check the fuses and if wires are the issue. The crankshaft position sensor uses the change in the magnetic field every time the reluctor ring passes, and sends pulses to the PCM to assist in ignition timing and the control of fuel injection. The ECT sensor which is also a thermistor changes its resistance to the flow of current with temperature and thus alters the voltage output which is fed to the PCM. Check whether the ECT is getting reference voltage and check the resistance of the ECT at cold as well as at normal operating condition. The IAC valve regulates the low speeds of the engine to control the driving of automobile whereas the IAT is a sensor whose function is to measure the temperature of intake air which it alters the voltage signal to the PCM. Knock sensor rules an engine knock, as the PCM states that the ignition timing be changed. The MAP sensor monitors the change in pressure inside the intake manifold and translates the same into voltage for the purpose of fuelling and controlling ignition timing. The MAF sensor relates to the airflow quantity entering the engine and the oxygen sensor measures the exhaust gas oxygen content. The Park/Neutral switch does not allow the engine to start unless the gear is in Park or Neutral and the power steering pressure switch raises idle rate under load. The TPS is installed on the throttle body and is responsible for monitoring the position of throttle valve in order to supply fuel and the VSS provides pulsing voltage signal to the PCM to be converted to mph.

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.

The Manifold Absolute Pressure (MAP) sensor monitors the intake manifold pressure changes resulting from changes in engine load and speed and converts the information into a voltage output. The ECM/PCM receives information as a varying voltage signal from closed throttle (high vacuum) to wide open throttle (low vacuum). The ECM/PCM uses the MAP sensor to control fuel delivery and ignition timing. Performing the following test will set a diagnostic trouble code and illuminate the Service Engine Soon light. Clear the diagnostic trouble code after performing the tests and making the necessary repairs. The MAP sensor is located on the upper intake manifold plenum. Check the terminals in the connector and the wires leading to the sensor for looseness and breaks. Repair as required. Before checking the MAP sensor, check the voltage supply and ground circuits from the ECM/PCM. Disconnect the electrical connector from the MAP sensor and connect the positive lead of a voltmeter to the gray wire terminal (and the negative lead to the orange/black or black wire terminal at the harness connector. Turn the ignition key On-the voltage should read approximately 5.0 volts. If the voltage is incorrect, check the wiring from the MAP sensor to the ECM/PCM. If the circuits are good, have the ECM/PCM checked at a dealer service department or other properly equipped repair facility. To check the MAP sensor operation, reconnect the connector to the MAP sensor and using a suitable probe, back probe the light green wire terminal of the MAP sensor connector. Connect the positive lead of a voltmeter to the probe and the negative lead to a good engine ground point. Turn the ignition key On-with the engine not running the voltage should read 4.0 to 5.0 volts. Start the engine and allow it to idle. The voltage should decrease to approximately 0.5 to 2.0 volts. If the test results are incorrect, replace the MAP sensor. Access the MAP sensor. On TBI systems, remove the air cleaner assembly. On Central SFI systems, remove the intake air duct and resonator from the throttle body. On MPFI systems, remove the upper intake manifold from the engine. Disconnect the electrical connector from the MAP sensor. Remove the retaining bolts and draw the MAP sensor. Replace the MAP sensor seal in the upper intake manifold, if equipped. Installation is the reverse of removal.

Various engine sensors and components have checking procedures,the engine coolant temperature (ECT) sensor is a thermistor that changes resistance with temperature, and a failure in the circuit can cause trouble codes. The resistance should be measured when cold and warm while ensuring reference voltage from PCM is around 5.0 volts for the verification. Manifold Absolute Pressure (MAP) Sensor monitors changes in intake manifold pressure then varies its voltage output accordingly. Look at the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes. Intake Air Temperature (IAT) Sensor acts as a thermistor where you can measure its resistance at different temperatures to make sure it changes as expected. Also, use a scan tool to monitor the IAT sensor for performance. The oxygen sensor in exhaust detects oxygen content which you can check its millivolt signal while warming up your engine. Check whether the oxygen sensor heater has correct voltage or not. Vehicle Speed Sensor (VSS) provides speed data to PCM which can be checked for reference voltage. Depending on the type of engine, Camshaft Sensor and Crankshaft Sensor should be checked for resistance and proper signal output. Finally, Knock Sensors detect engine knock which should be checked for reference voltage and resistance. If any component fails these checks, replacement may be necessary.

Various engine sensors and components have checking procedures,the engine coolant temperature (ECT) sensor is a thermistor that changes resistance with temperature, and a failure in the circuit can cause trouble codes. The resistance should be measured when cold and warm while ensuring reference voltage from PCM is around 5.0 volts for the verification. Manifold Absolute Pressure (MAP) Sensor monitors changes in intake manifold pressure then varies its voltage output accordingly. Look at the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes. Intake Air Temperature (IAT) Sensor acts as a thermistor where you can measure its resistance at different temperatures to make sure it changes as expected. Also, use a scan tool to monitor the IAT sensor for performance. The oxygen sensor in exhaust detects oxygen content which you can check its millivolt signal while warming up your engine. Check whether the oxygen sensor heater has correct voltage or not. Vehicle Speed Sensor (VSS) provides speed data to PCM which can be checked for reference voltage. Depending on the type of engine, Camshaft Sensor and Crankshaft Sensor should be checked for resistance and proper signal output. Finally, Knock Sensors detect engine knock which should be checked for reference voltage and resistance. If any component fails these checks, replacement may be necessary.

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.

The Engine Coolant Temperature (ECT) sensor is normally located near the thermostat or at any rate, wherever the thermostat is mounted; for the Luxgen 3.4L, the sensor is sited towards the rear of the right cylinder head on the lower intake manifold . It also works as a thermistor, that is, its resistance decreases or increases depending on the temperature. When you plan to install a new sensor, it is better to thread the wires with Teflon sealing tapes to avoid leakage and corrosion. In order to uninstall the sensor, one has to unlock the locking tab, disconnect the electrical connector and, carefully, unscrew the sensor as its damage might provoke a failure in the fuel injection system. Installation is done in the reverse sequence as well, and levels of coolant have to be checked afterward. MAF is an intake air sensor mounted in the air intake tube between throttle body and air cleaner housing or on the throttle body on 1995 and later 3800 models. It measures the air, getting into the engine and, in some engines, it could be supplemented by the MAP sensor. To remove the MAF sensor, one has to unplug the electrical connector, unscrew the clamps and then remove it. For the 1995 and later 3800 engines to remove the sensor one has to take out screws thus to interpolate it one has to reverse the procedure of removal. The Manifold Absolute Pressure (MAP) sensor is located at the front of the engine on 1995 and later 3800 engines, this is on the upper intake manifold or firewall. It also checks on changes in the intake manifold pressure occasioned by changes in the engine load and speed. To dismantle it, first, disconnect the vacuum hose, pull the electrical connector and then unbolt the mounting screws. On 3.4L models, the retaining bracket and bolt must be removed, then pull it straight up; On 1995 and later models, the retaining clips must be disengaged. The Intake Air Temperature or (IAT) sensor is located downstream of the air filter, or in the housing of the air cleaner and performs the thermistor role. To remove it, disconnect the electrical connect or unscrew or twist it from its place and for installation twisting or screwing the electrical connector in place is done. Instruments called oxygen sensors, fitted in the exhaust manifold or pipe, measure the oxygen in the exhaust emissions and supply a voltage signal to the PCM to regulate the mixture. These are the following special precautions for the pigtail and the electrical connector; no contact with contaminants, and must have ample airflow to the IP67 rating standard. To remove an oxygen sensor, you have to remove the battery, lift the car, remove any heat shields around the sensor, remove an electrical connector and then unscrew the sensor; before tightening the new sensor, apply anti seize to the threads. Tps is an electro-mechanical device positioned on the throttle shaft of the throttle body whereby its main function is to detect the position of the throttle valve. Crankshaft position sensors depends with the kind of engine as some may have a single sensor and others a dual sensor which are all used to monitor crankshaft position and speed for ignition control. Replacement entails removal of the battery, the electrical connector as well as the sensor, while installment is the process of the vice versa. This is typically found at the front of the engine block or may be mounted on the left cylinder head and generates a signal for the PCM for the intake stroke of number one piston. The Vehicle Speed Sensor (VSS) is installed at the rear of the transaxle housing which employs an electrical pulse and voltage signal to the PCM for the measurement of speed. In its stead, pull the retaining bolt and disconnect the sensor. Controls the park/neutral function when the automatic transaxle is engaged and controls various systems based on whether the transaxle is in 'Park' or 'Neutral'; should not be disconnected during driving. Part of the steering gear, the Power Steering Pressure Switch conveys information to the PCM about high hydraulic pressure and influences engine idle and air conditioning; to remove it, one has to detach the electrical connector and unscrew the sensor.

The PCM sends a 5 volt reference signal to the MAP sensor and monitors the sensor output voltage to determine the manifold pressure.