GM 19211437 Sensor,Exhaust Oxygen

Almost all elements have an extended warranty required by the Federal government, so it is unwise to check or replace any of them while under warranty. After the warranty period has lapsed, you may opt to do checks or replacements for lesser money. The oxygen sensor is placed in the exhaust manifold and measures the concentration of oxygen in the exhaust gas with another in the catalytic converter for recheck of emissions level. An open or shorted oxygen circuit will set a code 13. Coolant temp sensor is a thermistor mounted on the intake manifold or TBI unit that provides voltage variations by the change in temperature; a faulty one causes a code 14, 15. To test it, the connector needs to be unplugged and the resistance needs to be checked with an ohmmeter, which, if does not correspond to the specified figure, means that the sensor is to be replaced. The manifold air temperature (MAT) sensor, placed in the air cleaner housing, determines the air temperature getting into the intake manifold and controls the fuel delivery; if it fails, the code 24 appears. The manifold absolute pressure (MAP) sensor supervises changes in intake manifold pressure converting this info into a voltage level for use by the ECM in delivery of fuel, among other functions; only unit substitution is doable in case of a failure. The cruise control module on 3.5L engines calculates fuel delivery based on throttle valve angle through throttle switch (TS) on manual transaxle models or by throttle position sensor (TPS) on automatic transaxle models, and such failures cause the code 21 or 22 and requires dealer service for diagnosis or for replacement. The VSS, incorporated into the speedometer, transmits a pulsing voltage signal to the ECM to be converted into MPH; a malfunction results in a code 24 and requires dealer troubleshooting. The Crank angle sensor which is mounted on the distributor produces pulsating AC voltage signal, which is used by the ECM to determine the engine speed and to control a number of devices.

Monitoring of the oxygen situation is performed with the oxygen sensor located in the exhaust manifold through the feedback to the ECM; the ions can vary an air/fuel mixture and instantly adjust the ratio for the maximum efficiency and minimal emission, with the optimum coefficient of 14.7 to 1. If the sensor is open, then it develops a Code 13, a low or high voltage issue causes the engine to run on open loop creating Codes 44 and 45. For the sensor to work correctly it must have good electrical connection; it must not be choked with excess air; it must come to operating temperature of about 600 °F (315°C) and should preferably use unleaded fuel. This requires a sharp focus during servicing not to damage the permanently attached pigtail and connector, do not let contaminants get near the electrical parts, do not use cleaning solvents, and ensuring that silicone boot is properly placed. In case of replacement, the sensor is fitted in a different location depending on the type of engine and must not be replaced if the engine is cold or below 120°F. The location of the silicone boot should be observed and the sensor pulled back very gently just to avoid stripping the threads. To facilitate easy unfastening at a later stage, some threads on the sensor require an anti-seize compound with the sensor subsequently tightened to the required torque and connected to the main engine wiring harness.

The oxygen sensor is located in the exhaust manifold or pipe and can be accessed from under the hood. It has a permanently attached pigtail and connector that should not be removed or damaged. Keep the sensor clean and handle it gently. Do not use cleaning solvents on it. The silicone boot must be correctly installed to prevent melting and ensure proper operation. Warm the engine to at least 120 degrees F before removing the sensor. Disconnect the electrical connector and carefully unscrew the sensor from the exhaust manifold. Use a special anti-seize compound on the threads for future removal. Install the sensor, tighten it to 30 ft-lbs, and reconnect the electrical connector.

The exhaust oxygen sensor is positioned in the exhaust stream to monitor the oxygen content in the exhaust gas.

These codes do not necessarily indicate a faulty sensor; they may reflect issues like a dirty air filter or vacuum leak instead.

The oxygen sensor should be carefully torqued to 30 ft-lb (4.1 m-kg).

The power steering pressure switch increases idle speed under load.

When removing and installing the oxygen sensor, use caution and do not remove the pigtail connector.

If the sensor is difficult to loosen, running the engine briefly can help.

A complete procedure is available for replacement.

Proper operation of the sensor relies on good electrical connections, unrestricted air supply, reaching the necessary operating temperature, and the use of unleaded fuel.

The ECM/PCM can detect oxygen sensor issues and set diagnostic trouble codes. When testing, be cautious, disconnect the sensor, and use jumper wires or backprobing to prevent damage, even though it may trigger a diagnostic trouble code.

The oxygen sensor in the exhaust monitors oxygen content. To check it, you can check its millivolt signal while the engine warms up. It is also important to inspect the oxygen sensor heater and ensure it receives proper voltage.

When replacing a post-converter sensor, ensure the vehicle is securely raised, disconnect the electrical connector, unscrew the sensor using the appropriate tool, apply anti-seize compound to the threads, and secure it while reattaching the electrical connector before lowering the vehicle.

The oxygen sensor in the exhaust monitors oxygen content. To check it, you can check its millivolt signal while the engine warms up. It is also important to inspect the oxygen sensor heater and ensure it receives proper voltage.

The oxygen sensor is located in the exhaust manifold on L4 engines and in the exhaust pipe in V6 engines.

The PCM controls the air conditioning compressor clutch to manage engine load.

It monitors intake manifold pressure changes due to engine load and speed.

On L4 models, the air cleaner should be removed before removing the oxygen sensor.

The Park/Neutral switch indicates to the ECM when the transaxle is in Park or Neutral, affecting the Transaxle Converter Clutch and Idle Air Control valve operation.