P0108: the manifold pressure sensor signal is reading too high
Some engines measure engine load with a manifold pressure sensor instead of, or alongside, an airflow sensor: it reads the pressure inside the intake manifold, which changes with how far the throttle is open and how hard the engine is working. This code means the electrical signal from that sensor is reading higher than the range the computer will accept, as if the manifold pressure were impossibly high. With this signal out of range, the engine control unit falls back on a default value instead.
You might notice
- The engine warning light comes on
- The engine may feel like it's getting too much fuel, with a rich smell from the exhaust
- manifold pressure sensor
- — a sensor that measures the pressure inside the intake manifold, which the computer uses to judge engine load
What the code itself says
P0108 is a powertrain (engine, gearbox and drive system) code, and the 0 after the letter means it is a generic code with a standard meaning.
Grouped here as: Engine running, fuelling and misfires — Air metering, fuelling, ignition, misfire, idle, boost, knock, oxygen sensors and the catalyst, all working together in the running engine. That grouping is ours, to help explain the code. The code's official family is the letter at the start.
This page is generic. Your car isn't.
A code on its own only tells you what the sensor saw, not what's actually wrong — and that changes next to your other codes. Read this one together with the rest of your scan and we'll work out what's really going on.
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