Powertrain (Engine & Gearbox)Standard EOBD

P0103 - Mass or Volume Air Flow Circuit High Input

Q: What are the symptoms of fault code P0103?

• Check Engine Light (MIL) illuminated • Engine hesitation or jerking during acceleration • Black smoke from the exhaust (running rich) • Significantly increased fuel consumption • Engine enters Limp Home Mode (reduced power) • Rough idling or stalling

Q: What causes fault code P0103?

• Most likely: Faulty Mass Air Flow (MAF) sensor (internal short) • Likely: Wiring short to voltage (12V or 5V reference) in the signal circuit • Possible: Contaminated sensor element (oil/debris) or severely restricted air intake • Rare: Poor ground connection at the MAF sensor connector causing signal float • Rare: Internal Engine Control Unit (ECU) failure

Q: How do you fix fault code P0103?

STEP 1: Inspect the air filter and intake ducting for blockages. Check the MAF sensor connector for corrosion or backed-out pins. STEP 2: Use a Multimeter to check the MAF sensor connector. You should see 12V (battery power), 5V (reference), and a solid ground (<0.1V drop). STEP 3: Use an OBD-II scanner to monitor live data. At idle, MAF readings should be approximately 2-7 g/s depending on engine size. If the reading is stuck at maximum (high g/s), check for a short to voltage in the signal wire. STEP 4: Clean the MAF element with dedicated MAF cleaner. If signal remains high after cleaning and wiring is confirmed okay, replace the MAF sensor with an OEM part.

Last updated:1 February 2026

Related:MAF, Kablage till MAF-sensor, Air Filter, Engine Control Module (ECM), TPS

System

Powertrain (Engine & Gearbox)

Related Fault Codes

P0100

Mass or Volume Air Flow A Circuit Malfunction

P0101

Mass or Volume Air Flow Circuit Range/Performance Problem

P0102

Mass Air Flow (MAF) Circuit Low Input

P0104

Mass or Volume Air Flow Circuit Intermittent

Technical Description

P0103 is stored when the Engine Control Module (ECM) detects that the Mass Air Flow (MAF) sensor signal voltage remains above a calibrated limit (typically >4.5V to 5.0V) for a set duration. This high frequency or voltage signal suggests an air volume level that is physically impossible at the current engine RPM and load. The ECM relies on this data for fuel injection timing; when the signal is implausible, the system defaults to 'Limp Mode' using Alpha-N logic (TPS and RPM) to prevent engine damage.

Possible Causes

Faulty Mass Air Flow (MAF) sensor (internal short)

Wiring short to voltage (12V or 5V reference) in the signal circuit

Contaminated sensor element (oil/debris) or severely restricted air intake

Poor ground connection at the MAF sensor connector causing signal float

Internal Engine Control Unit (ECU) failure

Symptoms

Check Engine Light (MIL) illuminated

Engine hesitation or jerking during acceleration

Black smoke from the exhaust (running rich)

Significantly increased fuel consumption

Engine enters Limp Home Mode (reduced power)

Rough idling or stalling

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Berörda ECU-familjer

BOSCH

ME7.0

6 OEM

P0103 - Mass or Volume Air Flow Circuit High Input

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have
other fault codes?

Berörda ECU-familjer

P0103 - Mass or Volume Air Flow Circuit High Input

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have other fault codes?

Berörda ECU-familjer

Do you also have
other fault codes?