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P0106 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.

Definition

The definition of a P0106 trouble code is “Manifold Air Pressure (MAP) Barometric Pressure Sensor Electric Circuit Output Range and Performance Problem.”

Meaning

P0106 is the OBD-II general code for an issue with the MAP circuit. It indicates the MAP circuit is having a problem with an incorrect voltage output range. This can also mean that the vehicle is having an issue with engine performance.

The MAP sensor plays a critical role in the fuel injection system. It sends signals to the Engine Control Unit (ECU) which makes for smoother operation and better fuel economy, along with the proper power and performance.

Causes

The source of the problem is that the MAP sensor range voltage output is incorrect. It is out of the programmed input that is required by the ECU.

The most common problem that tends to cause a P0106 trouble code is that an air intake system vacuum or intake hose is loose, cracked, or missing its plastic fittings and clamps.

The wiring or MAP sensor may be bad, brittle, cracked, have a bad connection or be too close to the higher voltage consumption components. They could be especially close to the alternators, ignition wires and other components as well.

A poor electrical ground can cause issues related to a P0106 trouble code. The sensor itself may be operating out of range. This can be caused by the fatigue of its internal components.

MAP sensors have to operate within specific ranges to send correct signals for the ECU. This is so that they can coordinate with the throttle position sensor and adjust correctly for the proper operation and running of the engine.

If the engine is not in good condition, is missing pieces or parts, has poor fuel pressure or  has an internal issue such as a burned valve, it can prevent the MAP sensor from receiving the correct output. There is a chance that the ECU could be faulty, but that is a rare cause for this problem.

Symptoms

P0106 code will be generally preceded by the Check Engine Light coming on the dashboard display. The vehicle in most cases will not run well, idle poorly, accelerate erratically, run rich, and backfire because the MAP sensor and throttle position sensor will not operate together properly.

Diagnosis

If you see a P0106 on your OBD- II scanner, a qualified technician should then reset the OBD- II fault codes. Then, that mechanic should perform a road test of the vehicle to see if the code returns.

The mechanic will be able to observe by watching live data streaming on the scanner while driving the vehicle. If the code comes back, the mechanic will need to perform a close inspection to see if the vacuum line and other hoses on the intake system are missing, loose, damaged, or disconnected. If these all appear to be correct and in proper working order, the technician should do a voltage output test on the sensor while the engine is running. This will help them determine if the output voltages fluctuate with engine speed and with the load put on the engine. They should be sure that all grounds are operating correctly since any ground related to the ECU could cause signal fluctuations from sensors.

Common mistakes

Diagnostic errors are typically due to not following the proper procedure, listed above. First, follow the test procedure in the diagnosis to ensure there are no intake air leaks such as a bad vacuum hose or connection. The technician must verify the voltage output of the MAP sensor is correct and fluctuates with the engine speed and proper voltage. Idle voltage is normally 1 to 1.5 volts and full throttle is usually around 4.5 volts. You should not buy a new MAP Sensor or ECU unless they are clearly at fault.

How serious is this?

The P0106 code will result in a poor running engine. Therefore, this is a problem that requires immediate attention. Take the vehicle to a skilled mechanic so you can have the vehicle diagnosed as soon as possible. The MAP sensor problem can cause excessive fuel consumption, rough operation and difficulty starting in some circumstances. It can cause other damage if the owner continues to drive it without proper diagnosis and repair. Occasionally, if no problems are found, the technician will be able to reset the fault codes and retest it to see if the code or engine light comes back on.

If the engine warning light turns on immediately at the startup of the vehicle, the OBD- II system can be reset and the vehicle should continue to operate normally.

What repairs can fix the code?

Repair manuals
  • Verify the code with an OBD-II scanner, here's a great one we use daily.
  • Reset the fault codes and perform a road test of the vehicle.
  • If the P0106 code comes back, follow the test procedure.
  • Inspect the vacuum lines and intake hoses for cracks, loose or missing parts and the electrical connector and wiring. Disconnect the electrical connector and then reinstall it to make sure it has a fresh and positive electrical connection. Check the voltage output on the MAP sensor to see if it falls within the correct range.
  • At this point, it is best to determine if the MAP sensor is defective and if it has no or incorrect output, then replace the MAP sensor. If all checks are good, then a final test to determine if the ECU is bad must be done.

Related codes

None listed.

Conclusion

Letting this trouble code go on without addressing it can lead to serious damage to the engine and the vehicle. A P0106 trouble code should be properly checked and diagnosed immediately. If the trouble code is confirmed, use the guide above to address and correct the issue. 

P0106 code – what does it mean & how to fix it

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