P0103 means Mass or Volume Air Flow Circuit High Input. The MAF sensor signal is higher than the computer considers possible, usually an electrical fault such as a short to voltage. It is a generic OBD-II code, so the definition is the same on any make, but the most likely cause varies by engine; confirm with a scan tool and the service information for your vehicle before buying parts.
What P0103 means
Most engine sensors receive a 5-volt reference and return a signal between roughly 0 and 5 volts. Codes ending in circuit high or circuit low usually point to an electrical fault: an open circuit, a short or an unplugged connector. Range/performance codes mean a signal is present but disagrees with what the computer expects from the other sensors, which more often points to a dirty sensor, an air leak or a mechanical problem.
P0103 symptoms
- Rough running or stalling
- Black smoke or a fuel smell
- Poor fuel economy
Common causes of P0103
- Short to voltage in the signal wiring
- Failed MAF sensor
- Poor ground
How to diagnose P0103
- Inspect wiring near ignition components and hot surfaces
- Check the signal and ground at the connector
- Compare MAF readings with expected values at idle and higher engine speed
Can you drive with P0103?
Usually drivable but may run rich; repair it soon.
P0103 tips
A high-input code that appears after aftermarket intake work can mean the sensor was mounted in a tube of a different diameter, which changes the reading; return the sensor to its original housing to check.
Will P0103 clear itself?
If the fault stops, the computer turns off the check engine light by itself after several drive cycles without seeing it again, and the code stays in memory as history for a while. Clearing P0103 with a scan tool after a repair is fine, but if the cause is still there the code returns, sometimes within one drive. Disconnecting the battery also clears codes on most vehicles, but it erases learned fuel trims and idle settings as well.
Related codes
| Code | Meaning |
|---|---|
| P0101 | Mass or Volume Air Flow Circuit Range/Performance |
| P0102 | Mass or Volume Air Flow Circuit Low Input |
| P0172 | System Too Rich (Bank 1) |
Guides that help
When it is more than a sensor
Sensor codes are usually fixed with a sensor, a connector, wiring or a leak repair rather than major parts. If testing turns up internal engine trouble instead, see how to tell if an engine is blown and compare engines by code on our engines page.
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