Manifold Absolute Pressure/Barometric Pressure Circuit High Input
The MAP sensor is reporting a higher voltage or pressure than expected.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine computer thinks the manifold pressure is too high, which could mean a problem with the MAP sensor or a vacuum leak.
What the computer is actually seeing
The Engine Control Module (ECM) expects the MAP sensor to provide a voltage between 0.5 to 4.5 volts. If it gets a reading above 4.5 volts, it sets the P0108 code.
What a healthy reading looks like
MAP sensor should read between 0.5V (at atmospheric pressure) and 4.5V (approximately 30 inHg).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Perform a visual inspection of the wiring and connectors related to the MAP sensor for damage or corrosion.
- 2Check the vacuum lines for leaks; ensure all connections are tight and intact.
- 3Using a multimeter, measure the voltage at the MAP sensor connector; it should be between 0.5V and 4.5V. If it's above 4.5V, suspect a faulty MAP sensor or a short.
- 4If voltage is normal, check the signal wire to the ECM for continuity and shorts while testing the MAP sensor voltage under various engine speeds.
- 5If all tests are normal, consider replacing the MAP sensor, as it may not be able to give accurate readings.
Common causes
- Faulty MAP sensor
- Electrical short or open in MAP sensor circuit
- Vacuum leak in intake manifold
- Faulty ECM
Typical repair cost
$$
Related codes
Frequently asked questions
Can I still drive with this code?
Yes, but performance may suffer, and fuel economy can be impacted.
Will this code come back after clearing it?
It can if the underlying issue isn't fixed, especially if there's a vacuum leak.
Why does this code pair with other codes?
Often, multiple sensors are affected by the same underlying issue, like a vacuum leak.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →