P0108
Fix within 1-2 weeksYour engine's computer is receiving a signal from the Manifold Absolute Pressure (MAP) sensor that is too high, indicating higher pressure than expected in the intake manifold.
Code P0108 means your engine's computer is getting a signal from the MAP sensor that's too high. Common causes: Faulty MAP sensor (70%), wiring issues (20%). Drivability: Limit driving, fix within 1-2 weeks. Repair cost: $30-$150 DIY, $100-$300 professional.
Can I Drive With P0108?
Limit driving, fix within 1-2 weeks
Essential trips under 10 miles, avoid highways and heavy acceleration. Expect poor performance and fuel economy.
Stop driving immediately if: Flashing Check Engine Light, significant power loss, loud engine noises, or a strong rotten egg smell from the exhaust.
Symptoms of P0108
- 1Check Engine Light is on
- 2Rough idle or stalling
- 3Poor acceleration or hesitation
- 4Reduced fuel economy
- 5Engine running rich (black smoke from exhaust, strong fuel smell)
- 6Hard starting
- 7Possible transmission shifting issues
Common Causes of P0108
Parts most likely causing this code, ranked by probability
A faulty MAP sensor can send an incorrect, high voltage signal to the engine computer, causing it to misinterpret intake manifold pressure.
70% of P0108 cases are fixed by replacing the MAP sensor
A short to voltage in the sensor's wiring harness or corrosion in the connector can cause the sensor signal to read artificially high.
20% of P0108 cases are fixed by repairing wiring or connector issues
In rare cases, the engine computer itself can malfunction and incorrectly interpret or process the MAP sensor's signal.
10% of P0108 cases are fixed by replacing the ECM/PCM
Check These First (Before Buying Parts)
- Inspect the MAP sensor's electrical connector for corrosion, bent pins, or loose connections.
- Check the wiring leading to the MAP sensor for any visible damage, chafing, or signs of a short.
- Ensure any vacuum lines connected to the MAP sensor are securely attached and free of cracks or leaks.
How to Diagnose P0108
- 1Visually inspect the MAP sensor and its electrical connector for damage, corrosion, or loose connections.
- 2Check the MAP sensor's vacuum hose (if applicable) for cracks, kinks, or disconnections.
- 3Using a multimeter, test the voltage at the MAP sensor connector to ensure proper reference voltage and ground.
- 4With a scan tool, monitor the live data from the MAP sensor with the engine off (KOEO) and at idle. Compare readings to specifications.
- 5Perform a vacuum test on the engine to rule out major vacuum leaks that could indirectly affect MAP readings (though high input is less common for leaks).
- 6If all other components check out, consider testing or replacing the MAP sensor.
P0108 on Popular Vehicles
Honda Civic
2006-2024Honda Civics are known to have MAP sensor failures that trigger P0108. The sensor is usually located on the intake manifold or throttle body and is relatively easy to access.
75% fixed by replacing the MAP sensor
Ford F-150
2004-2024On Ford F-150s, P0108 often points to a faulty MAP sensor. Check the wiring harness carefully for any signs of chafing or damage, especially near the sensor connector, as this can also cause intermittent high readings.
65% fixed by replacing the MAP sensor, 25% by wiring repair
Chevrolet Silverado
2007-2024Chevrolet Silverados can experience P0108 due to a failing MAP sensor. Ensure the sensor's mounting surface is clean and the O-ring is sealing correctly, as a poor seal can sometimes affect readings, though less commonly causing a high input.
70% fixed by replacing the MAP sensor
Frequently Asked Questions
What does P0108 mean?
P0108 indicates that the Manifold Absolute Pressure (MAP) sensor is sending a voltage signal to the engine's computer that is higher than expected for the current engine conditions.
Can I drive with P0108?
Limit driving, fix within 1-2 weeks. While your vehicle might still run, ignoring this code can lead to poor fuel economy, rough engine performance, and can cause expensive damage to your catalytic converter over time.
Will P0108 clear itself?
No, P0108 will not clear itself. The Check Engine Light will remain on until the underlying issue causing the high MAP sensor input is diagnosed and repaired. You will need to clear the code with a scan tool after the repair.
How do I fix P0108 myself?
Start by inspecting the MAP sensor's electrical connector and wiring for damage. If they look good, the most common fix is replacing the MAP sensor itself. This is usually a straightforward job involving disconnecting the electrical connector and removing a bolt or two.
How much does it cost to fix P0108?
DIY repair costs for P0108 typically range from $30 to $150 for a new MAP sensor. Professional repair at a shop will cost between $100 and $300, including parts and labor.
P0108 keeps coming back - why?
If P0108 keeps returning, it indicates the initial repair did not address the root cause. This often points to a wiring issue (a short to voltage), a faulty electrical connector, or, in rare cases, a problem with the engine's computer (PCM) itself.
Will P0108 fail emissions/smog test?
Yes, P0108 will cause your vehicle to fail an emissions or smog test. The Check Engine Light being on is an automatic failure, and the underlying issue of incorrect fuel mixture can also lead to high emissions readings.
What's the difference between P0107 and P0108?
P0107 indicates a 'low input' from the MAP sensor, meaning the signal voltage is too low, suggesting a vacuum leak or a short to ground. P0108 indicates a 'high input,' meaning the signal voltage is too high, suggesting a short to voltage or a faulty sensor reading high.
P0108 on Honda Civic
On Honda Civics, P0108 is most commonly caused by a failing MAP sensor. Inspect the sensor's electrical connector for corrosion or damage, but be prepared to replace the sensor itself. Aftermarket sensors can sometimes be problematic, so consider a quality replacement.
Questions to Ask Your Mechanic
Did you check the MAP sensor's signal voltage with a scan tool at idle and under load?
Good answer: Yes, I monitored the live data. At idle, it was reading X volts, and under acceleration, it went to Y volts. These readings are outside the manufacturer's specified range of A-B volts.
Have you inspected the wiring harness for the MAP sensor for any shorts to voltage or corrosion?
Good answer: Yes, I performed a continuity test and checked for shorts to the battery voltage on the signal wire. I also cleaned the connector pins and checked for any signs of damage.
Repair Cost Estimate
DIY Repair
Parts only
$30-$150
Shop Repair
Parts + labor
$100-$300
Save $70-$150 by doing it yourself
Difficulty
beginner
Time
0.5-1 hours
Beginner-friendly - Replacing a MAP sensor typically involves basic hand tools and is accessible for most DIYers.
Cost of Waiting
Ignoring P0108 causes your engine to run rich, wasting fuel and potentially damaging your catalytic converter. A $50-$150 MAP sensor replacement now prevents a $800-$2,500 catalytic converter replacement later.
While You're In There...
If the MAP sensor is mounted on or near the throttle body, replacing the gasket ensures a good seal and prevents future vacuum leaks in that area.
A clean air filter ensures proper airflow to the engine, which is critical for accurate sensor readings and overall engine performance.
Tools You'll Need
- OBD-II Scan Tool
- Multimeter
- Socket set or wrench (for sensor bolt)
- Screwdriver (for hose clamps if applicable)
- Electrical contact cleaner
P0108 is a common sensor code. Most repairs involve replacing the MAP sensor, which is a straightforward job that will restore your engine's performance and fuel economy.
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Your Next Steps
Step 1: Visually inspect the MAP sensor's electrical connector and wiring for any obvious damage or corrosion. Clean the connector with electrical contact cleaner.
Step 2: If the wiring and connector appear good, use an OBD-II scan tool to monitor the live data from the MAP sensor. Compare the voltage readings to your vehicle's specifications (often found in a repair manual).
Step 3: If the sensor readings are consistently high and the wiring is confirmed good, replace the Manifold Absolute Pressure (MAP) sensor. You'll likely need a new MAP sensor and possibly a new O-ring or gasket.