What does P0108 mean?
The manifold absolute pressure (MAP) sensor measures pressure (vacuum or boost) inside the intake manifold. The computer uses it for fuel and ignition timing, and on turbo engines to monitor boost.
The signal is reading higher than the sensor can normally produce, which points at a wiring fault or a dead sensor.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Check engine light
- Rough idle
- Hesitation
- Poor fuel economy
- Hard starting
Common causes
- Open sensor ground wire
- Signal wire shorted to the 5 V reference or to battery voltage
- Water in the connector
- Failed sensor
How to diagnose P0108
- Check the sensor ground first: an open ground drives the signal high.
- Unplug the sensor: if the signal still reads high, look for a short to voltage in the harness.
- If the wiring is good, replace the sensor.
- With the key on and engine off, the MAP reading should match barometric pressure (about 14.7 psi / 101 kPa at sea level).
- At warm idle, a healthy gas engine usually shows roughly 18 to 22 inHg of vacuum (around 25-35 kPa).
How to fix it
- Replace the vacuum hose
- Repair wiring
- Replace the MAP sensor
Estimated repair cost
Likely repairs for P0108 run from about $100 to $450, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| MAP sensor replacement | $100 - $300 |
| Vacuum leak repair (hose/gasket) | $100 - $450 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0108?
Moderate severity
Usually drivable, but fuel economy and performance will suffer.
P0108 FAQ
What does P0108 mean?
P0108 stands for "Manifold Absolute Pressure/Barometric Pressure Sensor Circuit High". The manifold absolute pressure (MAP) sensor measures pressure (vacuum or boost) inside the intake manifold.
Can I drive with a P0108 code?
Usually drivable, but fuel economy and performance will suffer.
How much does it cost to fix P0108?
It depends on the cause. The likely repairs for P0108 range from about $100 to $450 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0108?
The most common causes are: open sensor ground wire; signal wire shorted to the 5 V reference or to battery voltage; water in the connector.