P0107
PowertrainManifold Absolute Pressure/Barometric Pressure Circuit Low Input
You'll usually notice this one as a car that idles roughly, hesitates when you put your foot down, and sometimes drops into limp mode with the warning light glowing. On a turbo or supercharged engine it can feel really gutless, like the boost has gone walkabout. The cause is the manifold absolute pressure sensor sending the ECU a voltage that's too low, below the bottom of the range it expects to see. Either the sensor has died, or something in its wiring and earth has gone open or shorted to ground.
ⓘ Information only. This page provides general educational information about fault code P0107. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0107 mean?
P0107 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Manifold Absolute Pressure/Barometric Pressure Circuit Low Input.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light on, often with the car feeling down on power
- • Rough, hunting idle that won't settle
- • Hesitation or a flat spot when you accelerate, very obvious on a turbo when boost should be building
- • Car drops into limp mode and refuses to rev past a certain point
- • Worse fuel economy, especially around town
- • Hard starting or the odd stall at idle when you come to a stop
- • Black smoke from the exhaust on some engines as the fuelling goes haywire
Possible causes
Causes commonly associated with P0107, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Failed MAP sensor reading near zero volts, the usual culprit on higher-mileage cars and a common wear item on VAG 1.9 and 2.0 TDI engines
- 2. Wiring fault in the sensor loom, a chafed or broken signal wire shorting to earth pulls the voltage straight down
- 3. Corroded or loose connector at the sensor, road salt and heat cycles get into these plugs over the years
- 4. Bad earth to the sensor, which fools the ECU into reading a permanently low signal
- 5. Damaged 5-volt reference feed from the ECU, less common but worth checking if the supply is dead
- 6. Sensor element gunked up with oil mist and carbon, typical on diesels with a leaky breather or knackered intake
- 7. A faulty ECU, but that's rare and the last thing you should suspect
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Back-probe the sensor connector with a multimeter and check the signal voltage with the ignition on. You want a sensible reading, somewhere near 4.5 to 5 volts at key-on with engine off on most setups, dropping as the engine pulls vacuum. A flat reading near zero points at sensor or wiring
- 2. Confirm the 5-volt reference and the earth are both present at the connector. No reference feed or a missing earth and the sensor can't read right no matter how good it is
- 3. Wiggle the loom and connector while watching live data. A signal that jumps about as you move the wiring tells you the fault is in the harness, not the sensor
- 4. Inspect the connector pins for green corrosion, spread terminals, or oil contamination, and clean them up
- 5. Compare MAP reading against barometric pressure with the engine off. They should roughly match at sea level. A big mismatch with a healthy supply means the sensor is lying
- 6. Clear the code, road test, and see if it comes straight back. If it does and the wiring checked out clean, fit a new sensor
Common questions about P0107
What am I likely to pay to sort this out? +
The MAP sensor itself is cheap, normally £20 to £60 for a decent aftermarket or OE-equivalent part. At an independent garage you're looking at maybe £60 to £150 all in once you add diagnostic time and fitting, more if the sensor is buried under intake pipework. A main dealer will often charge £150 to £250 for the same work. If the real fault turns out to be a chafed wire or a corroded earth, it can be a near-free fix once you've found it, just the labour to repair the loom.
How do I know if it's the sensor or just dodgy wiring on my car? +
Get a multimeter on the connector before you spend a penny on parts. If the 5-volt feed and earth are both good but the signal sits stuck near zero, the sensor is your problem. If wiggling the loom makes the live reading jump around, or you've no reference voltage at all, the fault is in the harness or the plug. Plenty of P0107s are just a corroded connector or a broken signal wire, so don't throw a sensor at it blind.
Can I clean or replace the sensor myself? +
Replacing it is well within reach for most home mechanics, usually one or two bolts and a connector, and a few minutes to drive it after. Cleaning can help on a gunked-up diesel sensor, use proper MAF/sensor cleaner spray and never touch the element with your fingers or a rag. That said, a clean only buys time if the sensor is on its way out. If the connector or wiring is the issue you'll need to repair that properly, a quick squirt of cleaner won't fix a broken wire.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →