P0108 Code: MAP Sensor High — Causes & Fix
P0108 means the manifold absolute pressure (MAP) sensor signal is too high — often read as low vacuum or a shorted circuit.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $30 – $350
- Time to fix
- 30 minutes – 2 hours
What it means
Common causes are a shorted MAP signal wire, a failed sensor, or a blocked/leaking vacuum reference. P0108 is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer petrol car or light truck regardless of make. Fix the underlying fault, then clear the code with an OBD-II scan tool — it will return if the problem isn't resolved.
Symptoms
- Check engine light on
- Rich running or black smoke
- Rough idle and poor economy
How to fix it
- 1
Check wiring and vacuum reference
1. Inspect the MAP wiring for shorts. 2. Confirm the vacuum port/hose is clear.
- 2
Test or replace the sensor
1. Compare the reading to actual manifold vacuum. 2. Replace the sensor if it reads high, then clear the code.
Frequently asked questions
Why is my car running rich with P0108?
A high MAP signal tells the ECM the engine is under more load than it is, so it adds too much fuel.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.