P0106: MAP Sensor Electric Circuit Performance Problem

What is P0106?

Error code P0106 is an OBD-II Diagnostic Trouble Code (DTC) defined as “Manifold Absolute Pressure Electric Circuit Output Range and Performance Problem.”

DTC P0106 is a generic diagnostic trouble code related to the manifold absolute pressure sensor (also called the MAP sensor, Barometric Pressure Sensor, or Baro sensor.) It indicates that your MAP circuit is suffering from an incorrect voltage output range or that there’s an engine performance issue.

The manifold absolute pressure sensor is integral to your vehicle’s fuel injection system. It measures your engine’s intake manifold pressure (atmospheric pressure) — which is directly related to the engine load. 

Your Engine Control Module (ECM) or Powertrain Control Module (PCM) combines readings from the MAP sensor and engine coolant temperature sensor (ECT sensor). It does this to calculate the mass air flow rate for an optimal fuel to air ratio.

In general, the MAP or Baro sensor is a 3-wire sensor connected to your PCM. The MAP sensor connector wires have these functions:

• One wire receives a +5V reference voltage from the PCM
• One is the ground wire
• One is the sensor signal wire that delivers the MAP sensor voltage 

Your MAP sensor typically sends a signal of between 1V – 4.9V, depending on your engine speed — whether it’s at full throttle, idle, or in between that. The P0106 code is prompted if the PCM notices the voltage fluctuating erratically, or if there isn’t a related change in the engine load. 

Common symptoms

You may experience one or more of these common symptoms with an active P0106 code:

• Illuminated Check Engine Light
• A rough-running engine
• Excessive smoke from the exhaust pipe
• Worsened fuel economy
• Erratic acceleration
• Poor idling

Can I still drive?

Technically yes, but it’s not recommended you continue driving with an active P0106 code.

With this error code active, you’ll experience decreased engine performance. You could also end up causing more damage to other engine components, like your emissions system.

Take your vehicle to a professional mechanic ASAP so they can diagnose and fix the underlying problem.

P0106 causes

These are the most common causes of diagnostic trouble code P0106:

• Bad MAP sensor: If the MAP sensor voltage output is outside the programmed input range required by your ECM, it triggers this fault code. If you have poor connectivity in your MAP sensor connector or electric circuit, it also won’t communicate effectively with your throttle position sensor (TPS sensor).
• Faulty air intake system: A fault in your air intake system is the most common cause of error code P0106. This code is often triggered by a loose intake hose, a dirty air filter, or a clogged MAF sensor. A clogged or dirty throttle body can also cause the P0106 trouble code.
• Vacuum leak: A faulty or clogged vacuum line (vacuum hose) means your manifold air pressure sensor won’t accurately measure the reading coming from your vacuum system.
• Engine damage: If your engine isn’t in good condition, has a burned valve, or is consuming too much fuel, it can prevent your MAP sensor from getting an accurate output reading.
• Defective ECM or PCM: If your ECM or PCM is faulty, they won’t measure the reading from your barometric pressure sensor correctly.

Diagnosis

Here’s how your mechanic will diagnose the issue to find the underlying cause of your P0106 fault code:

• First, they’ll use a scan tool to see if you have any other active fault codes alongside DTC P0106.
• Then, they’ll check the vacuum line (vacuum hose), air intake hose, and intake duct for a vacuum leak. They’ll also make sure that each connector is present and fitted tightly.
• Next, they’ll use a scan tool to check your manifold pressure reference voltage. The MAP sensor signal voltage should drop from 4.5 volts to about 1 volt and fluctuate with the engine speed. If it doesn’t, there’s a problem with the wiring or the sensor itself.
• They’ll then use a digital multimeter to check the signal wire to the manifold absolute pressure sensor to test for shorts.
• Then, your mechanic will inspect your air intake system. They’ll look for a clogged MAF sensor or throttle body as well as for a loose intake hose.
• Finally, your mechanic will inspect your ECM and PCM for damage.

Possible repairs for P0106 & Costs

Before moving on to repairing your active P0106 check engine light code, your mechanic must entirely complete the diagnostic process.

You don’t want to pay for a new PCM when a short circuit in your MAP sensor wiring is causing the problem.

Here’s how your mechanic will fix the issue, depending on the problem:

• Other engine light codes: Your mechanic will fix any other error codes you have in order or seriousness.
• Air intake system issues: If required, your mechanic will replace your air intake hose and clean your air filter. They’ll also tighten your connectors and clear your MAF sensor of any debris.
• Bad MAP sensor (baro sensor): Your mechanic will replace all your MAP sensor wiring if it’s frayed or corroded. They’ll also replace your MAP sensor connector. If the problem persists, they’ll try to reprogram or replace your MAP sensor.
• ECM and PCM: Damaged engine computers are rarely the cause of error code P0106. But, if required, your mechanic will reprogram or replace your Engine Control Module and Powertrain Control Module.

Here’s an estimate of what you can expect to pay, depending on the problem:

• Air intake system: $50-$500
• New MAP sensor: $150-$250
• ECM replacement: $800-$1500
• New PCM: $1000-$1200
• Vacuum leak repair: $150-$1000

Note: The repair job estimates above include labor charges.