Powertrain Codes

Good

P0108

Manifold Absolute Pressure Circuit High Input

★★★★★ Common diagnostic code

P0108 indicates the engine computer detected a problem related to manifold absolute pressure circuit high input. Airflow measurement is critical for fuel delivery, ignition timing, emissions, and engine performance.

Atlas Quality75% · Good
Editorial StatusGood
SystemUnderstanding Fuel Delivery Systems
SeverityMedium
Can I keep driving?Use caution and diagnose before replacing parts.
Typical repair cost$80-$900
Typical labor0.5-2.5 hours

Atlas Academy

Learn the System

Before diagnosing this code, it helps to understand the system behind it.

Read Understanding Fuel Delivery Systems

What P0108 Means

P0108 indicates the engine computer detected a problem related to manifold absolute pressure circuit high input. Airflow measurement is critical for fuel delivery, ignition timing, emissions, and engine performance.

Before You Replace Anything

Record the evidence first. Clearing codes too early can erase the clues that point to the real fault.

✓ Save freeze-frame data✓ Check for additional trouble codes✓ Look for technical service bulletins✓ Verify battery voltage✓ Verify engine oil level and coolant level✓ Perform a visual inspection✓ Do not clear the codes yet

Common Symptoms

⚠ Check Engine Light⚠ Poor performance⚠ Reduced fuel economy⚠ Rough idle⚠ Possible hesitation

Most Common Causes

Dirty sensor90%
Faulty sensor78%
Vacuum leak66%
Damaged wiring54%
Connector corrosion42%
Aftermarket intake issue30%

Diagnostic Confidence

MAF sensor88%
MAP sensor78%
Air filter68%
Connector58%
Intake boot48%

Use this as a starting point, not a replacement for testing.

Recommended Diagnostic Workflow

1Record freeze-frame data
2Inspect intake tubing and air filter
3Inspect wiring and connectors
4Review live scan data
5Compare readings to specifications
6Repair confirmed fault
7Clear codes and verify repair

Mechanic's Tips

Tip #1

Do not replace the sensor until the intake system, wiring, power, ground, and live data have been verified. Dirty MAF sensors and intake leaks are common causes.

Common Mistakes to Avoid

✕ Replacing parts before testing power, ground, and signal circuits✕ Ignoring related codes and freeze-frame data✕ Skipping the visual inspection✕ Clearing codes before confirming the repair

Common Repairs

Repair wiring

Success Rate: ★★★☆☆

Average Cost: $80-$900

Labor: 0.5-2.5 hours

Replace confirmed failed sensor

Success Rate: ★★★☆☆

Average Cost: $80-$900

Labor: 0.5-2.5 hours

Repair intake leak

Success Rate: ★★★☆☆

Average Cost: $80-$900

Labor: 0.5-2.5 hours

Clean sensor if appropriate

Success Rate: ★★★☆☆

Average Cost: $80-$900

Labor: 0.5-2.5 hours

Parts Commonly Replaced

MAF sensorMAP sensorAir filterConnectorIntake bootHarness

Tools Used During Diagnosis

OBD-II scan toolDigital multimeterBasic hand toolsManufacturer service information

Related Repairs

Diagnostic workflowComponent testingWiring inspectionRepair estimate checklist

How to Explain This to Your Customer

This code points to a problem in the air measurement system. Proper testing should confirm the root cause before replacing components.

Manufacturer Notes

Generic OBD-II information. Exact diagnostics vary by manufacturer.

Technician Notes

Do not replace the sensor until the intake system, wiring, power, ground, and live data have been verified. Dirty MAF sensors and intake leaks are common causes.

Related Codes

P0171 P0174 P0300 P0420 P0113 P0112

FAQ

Can I drive with P0108?

It depends on symptoms, but diagnosis should be performed promptly.

What should I check first for P0108?

Begin with freeze-frame data, visual inspection, and scan tool data before replacing parts.

Will P0108 turn on the Check Engine Light?

Yes, in most cases.

Project Atlas Feedback

Was this article helpful?

👎 Needs Improvement
Project Atlas Built by mechanics. Improved by mechanics.

Working on this repair?

Create a professional estimate in minutes.

✓ Email it to your customer✓ Track labor and parts✓ Convert it into an invoice✓ Keep a complete repair history
Start Free PistonCMS Account

Project Atlas

Chapter Status

Quality Score75%
Editorial StatusGood
Last ReviewedPending review
Template Version1.3.4
Related Academy GuideUnderstanding Fuel Delivery Systems

Editorial Readiness

Reference Chapter Checklist

✓ Academy linked○ Quality Score ≥95✓ FAQ complete✓ Customer explanation✓ Internal links○ Reviewed

Why Trust This Guide?

✓ Updated regularly✓ Written for working technicians✓ Practical diagnostic process✓ Built for mobile mechanics and independent shops✓ Maintained by PistonCMS

Built by mechanics. Improved by mechanics.

This guide is maintained for working mechanics, mobile technicians, fleet maintenance professionals, and independent repair shops.