P0108 Code Meaning and Next Steps

First checks take 10 to 15 minutes for the first checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The engine starts running much worse, stalls, or the warning light flashes.
!The vehicle begins to overheat or lose power sharply while the code is active.

If the light is steady and the vehicle still drives normally: Often yes for a short time, but it should not be ignored.

What to check first

Step-by-step checks

1
Free - no tools
Inspect the MAP connector and harness for an open circuit, loose fit, or damaged pins
2
Free - no tools
If the sensor uses a vacuum hose, make sure it is connected and not split or blocked
3
Basic tool needed
Compare key-on engine-off MAP data with the local barometric reading if scan data is available
4
Basic tool needed
Check for contamination, water, or obvious damage in the sensor port or connector
5
Basic tool needed
If the code appeared after repair work, verify the hose routing and connector seating first

If the code returns

-If the signal stays high with the hose confirmed and the harness still, circuit testing is the next step.
-If moving the connector changes the reading, the wiring side becomes more likely than the sensor body alone.
-If the code returns after a replacement, revisit the reference and ground side before assuming the new part is bad.

Background

What this code means

P0108 is a generic OBD-II manifold absolute pressure (MAP) sensor code.

A high signal can come from an open circuit, a disconnected vacuum source, or a sensor that is biased high under load.

Rich-running behavior, hesitation, or a load reading that seems too high can show up when the signal is pulled upward.

Diagnosis

Common causes

Most common

Open signal circuit

A break in the circuit can make the reading jump high.

Common

Disconnected vacuum hose

A hose-fed sensor will read wrong if the vacuum source is lost.

Common

Failing MAP sensor

The sensor can drift high internally even if the connector looks fine.

Possible

Connector or pin issue

A poor connection can behave like a high-input fault.

Avoid these mistakes

What not to do

xDo not replace the sensor first if there is an obvious wiring, connector, or intake issue.
xDo not ignore drivability changes just because the code sounds like a sensor problem.

Parts

Parts that may need replacing

PartTypical costNotes

MAP sensor$40-$160Relevant when the sensor or circuit tests poorly.

Vacuum hose$10-$40Worth replacing if the line is cracked, loose, or disconnected.

Connector repair$15-$90Useful if the plug or pins are damaged.

Related OBD codes

P0105

P0105 usually means the MAP sensor circuit has a malfunction.

P0106

P0106 usually means the MAP signal is outside the expected range or performance window.

P0107

P0107 usually means the MAP signal is reading too low.

P0109

P0109 usually means the MAP signal is intermittent or erratic.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0108 was expanded around common high-input MAP faults, including open circuits, disconnected vacuum lines, and sensor bias.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0108 - P0108 Usually Means the Map Signal Is Reading Too High