P0108

Universal

Manifold Absolute Pressure/Barometric Pressure Circuit High Input

Definition source: General OBD-II reference catalog

Definition verification: Not independently verified for display.

Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium

Medium Severity

The engine computer has detected a signal that is higher than expected in the manifold absolute pressure (MAP) or barometric pressure circuit. The MAP sensor helps the computer estimate engine load, while barometric pressure information reflects surrounding air pressure. A high signal may affect fueling and engine performance, but the code alone does not prove that a sensor needs replacement.

Report an error with this code

⚠️ Before You Begin (Safety First)

If the engine stalls, loses power, runs very poorly, or is difficult to control, stop in a safe place and arrange assistance. If the vehicle remains stable, avoid demanding driving and have the fault diagnosed promptly.

Common Symptoms

The check-engine light may be on, with no noticeable change in how the vehicle drives.
Rough idle or unstable running may occur if the engine computer receives pressure information that leads to unsuitable engine-control adjustments.
Hesitation, reduced power, or poor acceleration may occur if the reported engine load is inaccurate.
Starting difficulties or stalling may occur in some cases, depending on how the fault affects engine operation.
Fuel consumption or exhaust emissions may increase if engine fueling is affected.

Common Causes

A MAP or barometric pressure sensor may produce an abnormally high signal because of an internal fault.
Damaged wiring or a short to voltage in the signal circuit may raise the reported input.
A poor electrical connection, corrosion, or damaged connector may disrupt the sensor signal or its reference or ground circuit.
A ground or reference-circuit problem may cause an incorrect sensor output.
Where applicable, a blocked, disconnected, or damaged pressure passage or hose may affect the pressure information reaching the sensor.

Diagnostic Steps

Check whether the check-engine light is accompanied by stalling, major power loss, or unsafe running; stop driving if the vehicle cannot be controlled reliably.
With the vehicle safely parked and the engine off, look for an obviously disconnected or damaged MAP sensor connector or pressure hose, if accessible.
Check visible wiring near the sensor for chafing, cuts, or contact with hot or moving parts; do not pull on wires or force connector terminals.
If you have a compatible scan tool, note the stored code and related pressure readings without treating them as proof of a failed sensor.
Use the vehicle-specific service information for any electrical tests or sensor removal; seek qualified help if the checks require probing terminals or the fault is not clear.

When to Call a Professional

A technician can compare scan-tool MAP and barometric readings under appropriate conditions, inspect the circuit and connector, and test sensor power, ground, and signal using vehicle-specific service information. These checks help distinguish a sensor fault from wiring, connection, or pressure-path problems.

Compare component listings

Confirm diagnosis and vehicle fitment before buying. A listing does not prove that a part needs replacement. We may earn a commission from qualifying purchases.

Search Amazon Search eBay

Commonly Asked Questions

Does P0108 mean the MAP sensor must be replaced?

No. It indicates a high input in the MAP/barometric pressure circuit. A sensor, wiring, connector, reference or ground issue, or pressure-path problem may be involved, so diagnosis should come before replacement.

What does “high input” describe?

It describes the signal detected by the engine computer as higher than expected. It does not by itself identify which component or circuit condition caused that signal.

Can I keep driving with P0108?

That depends on how the vehicle runs. If it stalls, loses substantial power, or is unsafe to control, stop in a safe place and arrange assistance. Otherwise, limit demanding driving and have it checked promptly.

How can a technician tell whether the sensor or wiring is at fault?

A technician can compare scan-tool pressure readings and test the sensor circuit, connector, power, ground, and signal using the specifications and procedures for the exact vehicle.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.