After you retrieve the trouble codes from your vehicle's on-board computer, you can now check the sensors. All the time refer to your aid manual for specifications on your make and model vehicle.
The first trouble code to check is the throttle position sensor (Tps). The Tps is located either on the side of the carburetor or the side of the fuel injected models. It is attached to the throttle body. Visually witness the sensor for worn insulation on the wires and a loose or cracked connection. Disconnect the sensor.
With the digital volt ohm meter or Dvom in the 20K ohm position, connect the unavoidable Dvom lead to the sensor's center terminal. connect the negative Dvom lead to one of the other sensors' terminals. Moderately move the throttle lever until it is at the wide-open position. Depending upon which final you linked the negative Dvom lead to, the Dvom reading should either increase or decrease steadily. Release the throttle lever slowly. If the Dvom reading is not gradual and steady, but moves instead at an irregular pace, the sensor is defective and should be replaced. Re-connect the sensor. Clear the trouble codes from the Ecm memory by disconnecting the negative battery cable for at least ten seconds.
Your next trouble code indicates a mass air flow (Maf). The Maf sensor is located in the middle of the air cleaner and machine throttle body. To test, start the engine. Take a screwdriver deal with and tap the Maf lightly some times on the plugin side. Do Not strike The Sensor With Force, It May Crack. If the machine staggers, misfires, or stops running, the sensor is defective and should be replaced. Clear the trouble codes from the Ecm memory by disconnecting the negative battery cable for at least ten seconds.
Start the oxygen sensor performing test by removing the sensor from the vehicle. The oxygen sensor is located either in the exhaust multiple or the exhaust pipe. Visually witness the sensor for worn insulation on the wire and a loose connection. Start the machine and let it run for about five minutes, then turn the machine off. Disconnect the sensor. Accumulate the sensor connector away from the exhaust manifold; tape the connector to the fender well, if possible. Turn the digital vote ohm meter to the millivolt setting, connect the unavoidable Dvom lead into the sensor connector terminal, and ground the negative Dvom lead to an unpainted ground. Restart the engine. witness the Dvom reading. It should fluctuate in the middle of 100 and 1,000 mv (0.1 and 1.0 volts). If the voltage does not fluctuate in the pattern indicated above, the oxygen sensor is faulty and should be replaced. Re-connect the sensor. Clear the trouble codes from the Ecm memory by disconnecting the negative battery cable for at least ten seconds. Do not set the digital volt ohm meter on the ohm meter setting to do so will damage the oxygen sensor.
The next trouble code indicates multiple air pressure (Map) sensor. The Map sensor is normally located on the firewall or the fender well. Visually witness the vacuum hose and sensor connector for deterioration or loose connections then disconnect the sensor. connect a jumper wire from final A on the Map sensor to final A on the connector. Using a second jumper wire, connect the final in the same way. Turn the ignition switch on. Do Not Start The Engine. With the digital volt ohm meter (Dvom) in the 20-volt Dc setting, connect the unavoidable Dvom lead to final B on the Map sensor. Ground the negative Dvom lead to an unpainted ground. witness the reading; it should be in the middle of 4.5 and 5 volts. Start the engine, let it idle. Keep the machine at idle and repeat the old step. If it does not change from the ordinal ones, the sensor is faulty and should be replaced. Reconnect the sensor. Clear the trouble codes from the Ecm memory by disconnecting the negative battery cable for at least ten seconds.
This is how to test some of the sensors on a vehicle. There are many more sensors on a car. There are other ways to test them depending on the make and model of the vehicle. When you get ready to retrieve trouble codes or test your sensors, All the time check the aid manual for specifications and how to test your sensors.
Your Vehicle's Sensors - How to Test Some of Them