What causes fault code P0150?

• Most likely: Faulty O2 sensor (internal short or open circuit) • Likely: Damaged wiring or contaminated connector (oil/coolant intrusion) • Possible: Exhaust leak upstream of the sensor affecting readings • Rare: Faulty Engine Control Unit (ECU) or software issue

How do you fix fault code P0150?

STEP 1: Inspect the Bank 2 sensor connector for corrosion or fluid intrusion. STEP 2: Measure the heater circuit resistance (usually 5-20 Ohms). Verify 12V supply to the heater. STEP 3: Use a scan tool to monitor live data. Induce a lean/rich condition (e.g., via a vacuum leak) to see if the sensor responds (should toggle 0.1V - 0.9V). STEP 4: If the sensor is unresponsive despite good wiring, replace the O2 sensor and clear adaptation values.

Powertrain (Engine & Gearbox)Standard EOBD

P0150 - O2 Sensor Circuit Malfunction (Bank 2, Sensor 1)

Q: What are the symptoms of fault code P0150?

• Check Engine Light (MIL) illuminated • Increased fuel consumption • Rough idling or hesitation during acceleration • Black smoke from exhaust under load • Failed emissions test

Last updated:1 February 2026

Related:Oxygen Sensor (Lambda), Engine Control Unit (ECU), Wiring Harness, Avgassystem

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

P0103

Mass or Volume Air Flow Circuit High Input

Technical Description

P0150 is set when the Engine Control Unit (ECU) detects an incorrect voltage signal from the upstream oxygen (O2) sensor on Bank 2. Normally, the sensor voltage oscillates between 0.1V (lean) and 0.9V (rich). If the voltage remains static for too long or exceeds specified limits, the ECU triggers this code. This fault prevents the engine from entering efficient 'Closed Loop' operation, causing the ECU to rely on 'Open Loop' maps, significantly impacting fuel economy and emissions.

Possible Causes

Faulty O2 sensor (internal short or open circuit)

Damaged wiring or contaminated connector (oil/coolant intrusion)

Exhaust leak upstream of the sensor affecting readings

Faulty Engine Control Unit (ECU) or software issue

Symptoms

Check Engine Light (MIL) illuminated

Increased fuel consumption

Rough idling or hesitation during acceleration

Black smoke from exhaust under load

Failed emissions test

Do you also have
other fault codes?

See how P0150 connects with your other fault codes. Our advanced analysis tool identifies causal relationships and root causes directly.

Analyze multiple codes

P0150 - O2 Sensor Circuit Malfunction (Bank 2, Sensor 1)

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have
other fault codes?

P0150 - O2 Sensor Circuit Malfunction (Bank 2, Sensor 1)

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have other fault codes?

Do you also have
other fault codes?