Fix P0107: Mechanic’s solutions that WORKED

The code P0107: Manifold Absolute Pressure (MAP) Sensor Circuit Low indicates a fault in the Manifold Absolute Pressure (MAP) Sensor Circuit, suggesting that the sensor’s signal to the PCM is abnormally low. This issue is often caused by problems with the sensor itself, its wiring, or a vacuum leak.

P0107 quick overview

Meaning	P0107: Manifold Absolute Pressure (MAP) Sensor Circuit Low
Is it serious?	Yes, it can affect the vehicle’s performance and fuel efficiency.
Possible causes	– Faulty or damaged MAP sensor – Wiring or connector issues – Vacuum leaks – Faulty PCM (Powertrain Control Module)
How to diagnose?	1. Inspect the MAP sensor and its connections for any visible damage or corrosion. 2. Check the wiring and connectors for continuity and ensure they are secure. 3. Verify the sensor is receiving the correct 5V reference and has a proper ground. 4. Test for vacuum leaks using methods like a smoke test. 5. If all else checks out, consider the possibility of a faulty PCM.

The code P0107 means that the sensor which measures the air pressure inside the engine is not working properly. It’s sending a signal that’s too low, which can cause the car to not drive smoothly and use more fuel than it should. It’s important to fix this to make sure the car runs well and doesn’t waste gas.

How to fix P0107 – learn from mechanics

I looked into P0107 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: Volvo

Vehicle Information 1998 Volvo V70 GLT 2.4L, MIL Lamp on

Issue + Repair History Technician encountered MIL on with code P0107. No MAP sensor found, but an altitude sensor was tested with KOEO voltage at 4.46V. Uncertain if this sensor was the cause of the MIL.

Other OBD2 Codes + Test Results Not applicable.

What Are People Suggesting to Fix Issue

• Investigate the Baro sensor located under the RF hood latch.
• Check for bad connection at the sensor or replace it if necessary, noting the high cost of replacement.

What Was the Final Fix The issue was resolved by tightening the terminals at the ‘Altitude Sensor’ or ‘Baro Sensor’. After securing the connections and clearing the codes, the P0107 did not return upon several miles of road testing.

Case #2: Ford

Vehicle Information 1999 Ford F-450 Super Duty Lariat 7.3L, MIL Lamp on

Issue + Repair History Technician faced an issue where the code P0107 would return immediately as a hard code after being cleared, causing high transmission line pressure and resulting in a blown front transmission seal. The passage, tube, and sensor were replaced with dealer parts, but the code persisted, leading to suspicions of a PCM problem.

Other OBD2 Codes + Test Results Not applicable.

What Are People Suggesting to Fix Issue

• Replace the baro sensor under the dash for models earlier than 99 1/2.
• Check the front pump bushing for blockage causing front seal leak.
• If the code returns immediately, the PCM might need replacement.
• Inspect the harness on the left-hand fender area for a short to ground.

What Was the Final Fix The final fix was replacing the baro sensor, which was located under the steering column and resembled a relay with a round plug. This solution prevented a potentially unnecessary expenditure on a new PCM.

Case #3: Kia

Vehicle Information 2009 Kia Rondo EX 2.4L, MIL Lamp on

Issue + Repair History Vehicle initially came in for a headlight bulb replacement. During the service, the battery went low, requiring a jump start, which led to a P0107 code indicating a MAP sensor issue. The code was cleared, and the original battery was replaced. However, the P0107 code reoccurred. A new MAP sensor was installed, but the datastream still showed 0.0 volts for the MAP sensor in all conditions, even after a wiggle test on the connection.

Other OBD2 Codes + Test Results P0107 – MAP sensor voltage below threshold. Datastream showed 0.0 volts for MAP sensor in all conditions.

What Are People Suggesting to Fix Issue

• Conduct basic checks including supply voltage, ground, and circuit integrity.
• Check for 5V reference to MAP and ground, along with a varying signal from the MAP sensor signal wire.
• Perform a capacitive discharge and a solid 10-mile test drive for relearning.
• Ensure the MAP sensor is receiving vacuum.
• Test all fuses for proper voltage and current carrying ability.

What Was the Final Fix The issue was resolved by re-testing the basics, which revealed that the wire back to the PCM was backed into the connector just far enough to not make contact. After securing the wire in place, the vehicle functioned normally.

Case #4: Mercedes

Vehicle Information 2011 Mercedes-Benz GLK350 3.5L, MIL Lamp on

Issue + Repair History Vehicle presented with P0107 code but no drivability issues. Harness tested with no issues found, and both 5 volts and ground were present. After installing a new MAP sensor, the code returned. When the sensor was unplugged, P0107 disappeared and P0108 (open circuit) appeared, which was expected. Notably, the 5 volts were lost when the MAP sensor was plugged in.

Other OBD2 Codes + Test Results P0107 – MAP sensor short to ground

What Are People Suggesting to Fix Issue

• Verify the pressure sensor and check the relevant fuse.
• Disconnect the other two wires on the same 5-volt line to see if the voltage remains constant, then reattach each one to locate the pull-down occurrence.
• Question the use of aftermarket MAP sensors and suggest using OE parts.
• Jump the sensor VREF to the signal wire to check the scanner display, ruling out other sensors on the line.
• Check for vacuum leaks with a smoke test, as incorrect vacuum can lead to incorrect voltage.

What Was the Final Fix The issue was resolved by using an Original Equipment (OE) part. Aftermarket MAP sensors were found to be unreliable, and installing an OE part resolved the problem.

Case #5: Chevrolet

Vehicle Information 2010 Chevrolet Malibu LS 2.4L, Surge, Misfire, MIL Lamp on

Issue + Repair History Vehicle arrived with MIL light on, storing codes P0106 and P0107 in the PCM. KOEO MAP reading was 98, dropping to 39 upon engine start. Light acceleration caused MAP to drop to 0, simulating a misfire, but hard acceleration seemed fine, ruling out exhaust and ignition issues. Replacing the MAP sensor did not resolve the issue.

Other OBD2 Codes + Test Results P0106 – MAP sensor range/performance P0107 – MAP sensor circuit low

What Are People Suggesting to Fix Issue

• Verify if the MAP/BARO sensor has low voltage and check for fuel trim issues.
• Confirm 5V reference and full ground, inspecting MAF hoses for any issues.
• Suspect a wiring issue, especially weak connections at the connector.
• Take a manual vacuum reading at idle and scope the 5V and low reference for glitches. If glitches are found, load test all wires from ECM to MAP. Also, consider unplugging VVT actuators and retesting.

What Was the Final Fix The final fix involved rechecking for ground reference and signal, which were found to be good. The next step was to replace the MAP, which had already been done. Upon further inspection, it was discovered that transmission lines had been leaking, and fluid had migrated into connectors. Cleaning the connectors with contact cleaner resolved the issue.

Advice	Brief Description of Diagnostic Step
Check Wiring and Connectors	Inspect the wiring and connectors for any signs of damage, corrosion, or loose connections.
Verify 5V Reference and Ground	Ensure that the MAP sensor is receiving the correct 5V reference and has a proper ground connection.
Replace with OE Parts	Use Original Equipment (OE) parts for replacement, as aftermarket parts may not function reliably.
Check for Vacuum Leaks	Perform a smoke test or other methods to check for any vacuum leaks that could affect sensor readings.
Test Circuit Integrity	Conduct tests to ensure the integrity of the circuit, including load testing wires from the ECM to the MAP sensor.
Recheck Basics	Revisit basic checks such as voltage, ground, and circuit integrity to ensure nothing was overlooked.
Clean or Replace Connectors	If fluid or debris has contaminated connectors, clean them thoroughly or replace if necessary.