P0108 Code – Manifold Absolute Pressure Circuit High Input

The P0108 diagnostic trouble code (DTC) indicates that the engine control unit (ECU) has detected a high voltage signal from the Manifold Absolute Pressure (MAP) sensor circuit.

This means the ECU interprets that pressure in the intake manifold is higher than expected, which can lead to incorrect engine load calculations.

The MAP sensor is critical for:

• fuel injection control

• ignition timing

• turbo boost regulation

Symptoms of Code P0108

Common symptoms include:

• Check Engine light ON

• Poor engine performance

• Engine hesitation

• Black smoke from exhaust (rich mixture)

• Increased fuel consumption

• Rough idle

• Hard starting

Common Causes of P0108

Typical causes include:

• Faulty MAP sensor

• Short circuit to power (high voltage)

• Damaged wiring

• Loose or corroded connectors

• Faulty vacuum line (blocked or disconnected)

• Intake system issues

• Faulty ECU (rare)

Sometimes, a blocked vacuum line can cause incorrect high pressure readings.

How Serious Is Code P0108

The P0108 code is considered a moderate to serious issue.

If ignored, it can lead to:

• rich fuel mixture

• increased fuel consumption

• catalytic converter damage

• poor engine efficiency

How to Diagnose Code P0108

Diagnosis steps:

1. Scan the vehicle with an OBD2 scanner

2. Check MAP sensor live data

3. Inspect vacuum lines

4. Check wiring and connectors

5. Measure MAP sensor voltage

6. Compare readings with specs

7. Test or replace the MAP sensor

How to Fix Code P0108

Possible solutions include:

• replacing the MAP sensor

• repairing wiring issues

• cleaning or replacing connectors

• fixing vacuum line problems

• cleaning intake system

• resetting ECU after repair

Vehicles Commonly Affected by P0108

This code is common on many vehicles:

• Opel

• Volkswagen

• BMW

• Ford

• Toyota

• Hyundai

• Renault

FAQ – P0108 Code

Can I drive with code P0108?

Yes, but the engine may run rich and consume more fuel.

Can a blocked vacuum line cause P0108?

Yes, incorrect pressure readings can trigger this code.

Is P0108 the opposite of P0107?

Yes. P0107 = low signal, P0108 = high signal.