Fix P0106: Mechanic’s solutions that WORKED

P0106 – MAP/BARO circuit means there is some problem with your manifold absolute pressure sensor that is essential for good engine performance. Start by testing the sensor with a multimeter because most of the time it’s either the sensor itself or the wiring/connector.

I studied this code on several real cases and I advise you to keep in mind that when you replace the sensor and the code keeps coming back, you might need to use an OEM sensor.

P0106 quick overview

Meaning	Manifold Absolute Pressure/Barometric (MAP) Pressure Circuit
Is it serious?	You can drive, but fix it ASAP to not cause other issues
Possible causes	– Faulty MAP sensor – Vacuum leaks in the intake manifold – Wiring or connector issues in the MAP sensor circuit – Issues with the powertrain control module (PCM)
How to diagnose?	– Check fuel trims to find if the car has a vacuum leak – New sensor didn’t fix it? You may need to use the OEM part – Test wiring/sensor with a multimeter – Visually check connector, sensor ,and wires for damage
What is MAP sensor?	1. Measures air pressure in the intake manifold. 2. Sends data to the engine control module (ECM). 3. Helps adjust fuel injection for optimal combustion. 4. Essential for engine performance, fuel efficiency, and emission control.

How to fix P0106 – learn from mechanics

I looked into P0106 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Chevrolet

Vehicle Information:
2016 Chevrolet Camaro SS
Engine: 6.2L

Issue + Repair History:

• Code P0106 (MAP Sensor Performance) was detected.
• The MAP sensor was replaced with an aftermarket part.

Suggestions from the Community:

• Use OEM parts.
• Check for vacuum leaks.
• Verify correct voltage readings.
• Consider the quality of aftermarket sensors.
• Inspect the throttle body and related components.
• Review GM service bulletin PIP5423B.
• Examine the rational relationship between MAP, TPS, IAT, and MAF.
• Clean the throttle body.

Final Fix:
Replacing the Mass Air Flow (MAF) sensor with the OEM unit resolved the P0106 code. Additionally, checking the throttle body, replacing a missing bolt, and cleaning resolved the issue.

Case #2: Volkswagen

Vehicle Information:
2009 Volkswagen Jetta SE
Engine: 2.5L

Issue + Repair History:

• Initially had a P0106 code.
• The customer replaced the MAP sensor.
• The code returned after two weeks.
• Voltage supply and sensor resistance were checked, showing similar readings to the original.
• Wiring continuity was checked, and the vehicle was referred to the dealership.
• The dealership suggested a weak battery, leading to its replacement.
• The alternator was also replaced based on the dealership’s recommendation.

Suggestions from the Community:

• Check if the PCV system is functioning properly.
• Perform a smoke test for air/vacuum leaks.
• Consider timing chain tensioner problems.
• Verify reference voltage at the MAP sensor.
• Check for cracked or broken ends of the MAP sensor.

Final Fix:
It was discovered that the PCV system was allowing oil to contaminate the sensor. The valve cover was replaced, excess oil was cleaned from the intake, and the MAP sensor was replaced. The code has not returned as of the last update.

Case #3: GMC

Vehicle Information:
2006 GMC C5500 Topkick C5C042
Engine: 6.6L

Issue + Repair History:

• Initially, there was no communication with the scan tool.
• A broken wire to the datalink connector was found and fixed, restoring communication.
• Code P0106 (MAP Sensor Performance) was detected.
• The engine was in reduced power mode.
• The wires were checked and found to be okay; the MAP sensor was then replaced.
• The engine remained in reduced power mode.

Suggestions from the Community:

• Check for possible intercooler leaks.
• Inspect the PCV hose and valve.
• Examine the intake manifold gasket.
• Verify if there are any modifications to the air intake or aftermarket performance additions.

Final Fix:
The MAP sensor was replaced again with another unit, which resolved the problem. The code has not returned as of the last update.

Case #4: Hyundai

Vehicle Information:
2009 Hyundai Sonata GLS
Engine: 2.4L

Issue + Repair History:

• Codes P0106 (MAP Sensor) and P0132 (O2 High Voltage) were detected.
• The customer reported rough running and chugging, but no issues were detected during shop scans.
• MAP voltage was 3.9V KOEO and 1.3V KOER.
• The 5V reference was available at the sensor, and the ground wire was good.
• O2 sensor voltage was switching normally.
• The MAP sensor had been replaced by the dealer previously.

Suggestions from the Community:

• Check the engine vacuum for possible breathing issues.
• Monitor short-term and long-term fuel trims at idle and 2500 RPM.
• Check for moisture in the MAP sensor hose.
• Verify if there are any vacuum leaks with a smoke machine.
• Verify fuel pressure with a gauge.
• Check for rodent damage to the harness.
• Test the TPS for proper operation and check for air leaks in the intake system.
• Ensure MAP and TPS follow each other closely on acceleration.
• Check electrical circuits for both codes.

Final Fix:
The MAP sensor installed by the dealer was found to be faulty. It was replaced with a new MAP sensor, resolving the problem. Both P0106 and P0132 codes have not returned as of the last update.

Case #5: Volvo

Vehicle Information:
2003 Volvo S60
Engine: 2.4T
Mileage: 80,000 miles

Issue + Repair History:

• Code P0106 (Manifold Absolute Pressure Sensor) was detected.
• The MAP sensor located on the radiator fan shroud and the attaching hose were replaced.
• The P0106 code reappeared a month later.
• The car occasionally stalled, according to the customer.

Suggestions from the Community:

• Check the signal wire to the computer and compare it with vacuum readings.
• Verify the condition of the ECM; there might be an issue with the second MAP sensor.
• Consider updating the ECM to eliminate false MAP sensor codes.
• Clean the Electronic Throttle Module (ETM) for potential idle issues.
• Check for updates related to the ECM flash from Volvo.
• Inspect the barometric sensor near the hood catch for possible failure.
• Verify the ground shared between the barometric pressure sensor and the AC pressure switch.
• Disconnect the battery for 30 minutes to reset adaptation codes.
• Ensure there are no leaks in the intake or hoses.

Final Fix:
Upon reinspection, a wiring issue with the MAP sensor’s plug was found. The wire was repaired, and all issues were resolved.