Blown fuse supplying power to the MAF sensor; Damaged or corroded wiring in the MAF sensor power circuit; Poor electrical connection at the MAF sensor connector; Faulty MAF sensor with an internal short or open circuit; Corrosion or water intrusion in the wiring harness or connector; Failed engine control module (ECM) power output (less common)

DTC codes / Volkswagen codes / P1146

P1146 · VolkswagenMass Or Volume Air Flow Circuit Power Supply Malfunction

Q: What does code P1146 mean?

Mass Or Volume Air Flow Circuit Power Supply Malfunction. P1146 on Volkswagen vehicles indicates that the engine control module (ECM) has detected a power supply malfunction in the mass air flow (MAF) sensor circuit. This means the voltage feed to the MAF sensor is outside the expected range, which can prevent the sensor from accurately measuring incoming air and disrupt fuel delivery calculations.

P1146 on Volkswagen vehicles indicates that the engine control module (ECM) has detected a power supply malfunction in the mass air flow (MAF) sensor circuit. This means the voltage feed to the MAF sensor is outside the expected range, which can prevent the sensor from accurately measuring incoming air and disrupt fuel delivery calculations.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or stumbling, especially when the engine is cold
Hesitation or lack of power during acceleration
Reduced fuel economy due to incorrect air mass readings
In rare cases, the engine may enter limp mode or stall

Common causes, most likely first

Blown fuse supplying power to the MAF sensor
Damaged or corroded wiring in the MAF sensor power circuit
Poor electrical connection at the MAF sensor connector
Faulty MAF sensor with an internal short or open circuit
Corrosion or water intrusion in the wiring harness or connector
Failed engine control module (ECM) power output (less common)

How to diagnose and fix it

Check the fuse that supplies power to the MAF sensor and replace if blown
Inspect the MAF sensor connector and wiring for damage, corrosion, or loose pins
Measure voltage at the MAF sensor power wire with the key on and engine off; compare to specification
Perform a voltage drop test on the power circuit to identify excessive resistance
If voltage is low, trace the circuit back to the ECM or fuse box to find the break
Replace the MAF sensor if the power supply is confirmed good but the sensor does not function
Clear the fault code and verify the repair by test-driving the vehicle

Don't overlook the simple power supply checks

A blown fuse for the MAF sensor is often caused by a shorted sensor or wiring, so simply replacing the fuse without finding the root cause will lead to a repeat failure.
Volkswagen MAF sensors are sensitive to voltage drops; even a small amount of corrosion at the connector can set P1146 without causing obvious driveability issues.
The code can be set intermittently by water intrusion into the connector, especially after car washes or heavy rain, so inspect for signs of moisture.
A faulty MAF sensor can sometimes still produce plausible readings, so don't assume the sensor is good just because the engine runs; always verify power and ground first.
Related codes such as P0102 or P0103 may also be stored, but P1146 specifically points to the power supply, not the signal circuit.

Can I keep driving with P1146?

If the vehicle is running normally, you can drive it to a workshop for diagnosis, but avoid heavy acceleration or towing. If the engine is stumbling, stalling, or in limp mode, stop driving and have the vehicle towed to prevent damage or unsafe operation.

Tools that help

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Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.