toyota P0105 - Manifold Absolute Pressure Circuit

If you own a Toyota vehicle and you see the P0105 code on your scanner, it means that there is a problem with the manifold absolute pressure (MAP) circuit. The MAP sensor measures the air pressure in the intake manifold and sends a signal to the engine control unit (ECU) to adjust the fuel injection and ignition timing. The MAP sensor is usually located on or near the throttle body.

The P0105 code indicates that the ECU is receiving an incorrect voltage from the MAP sensor. This could be caused by a faulty MAP sensor, a wiring issue, a vacuum leak, or a problem with the ECU itself. Some of the symptoms of this code are poor engine performance, hesitation, stalling, rough idle, poor fuel economy, and check engine light on.

To diagnose and fix the P0105 code, you will need a scan tool, a multimeter, and a vacuum pump. Here are some steps you can follow:

1. Check the MAP sensor for any visible damage or loose connections. If you find any, replace or repair them as needed.

2. Check the wiring and connectors between the MAP sensor and the ECU for any signs of corrosion, short circuits, or open circuits. If you find any, replace or repair them as needed.

3. Check the vacuum hose that connects the MAP sensor to the intake manifold for any cracks, leaks, or blockages. If you find any, replace or repair them as needed.

4. Connect the scan tool to the OBD-II port and monitor the live data from the MAP sensor. Compare the readings with the specifications for your vehicle. If they are out of range, proceed to the next step.

5. Disconnect the MAP sensor connector and use the multimeter to measure the resistance between the terminals of the sensor. Compare the readings with the specifications for your vehicle. If they are out of range, replace the MAP sensor.

6. Connect the vacuum pump to the MAP sensor and apply vacuum while monitoring the voltage output from the sensor with the multimeter. Compare the readings with the specifications for your vehicle. If they are out of range, replace the MAP sensor.

7. If all the tests above are passed, then you may have a problem with the ECU itself. You may need to reprogram or replace it.

The P0105 code can affect your Toyota's performance and emissions. Therefore, it is important to fix it as soon as possible. By following these steps, you can troubleshoot and repair this code yourself or take your vehicle to a professional mechanic for further assistance.