What causes fault code P0141?

• Most likely: Failed heater element inside the oxygen sensor (Bank 1, Sensor 2) • Likely: Corrosion or poor connection in the sensor connector • Possible: Wiring harness damage (rubbing against exhaust or chassis) • Rare: Blown fuse for the O2 heater circuit or faulty relay • Rare: Internal ECU failure

Powertrain (Engine & Gearbox)Standard EOBD

P0141 - O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)

Q: What are the symptoms of fault code P0141?

• Check Engine Light (MIL) illumination • Failed emissions test • Slightly increased fuel consumption during warm-up phase • Increased tailpipe emissions during cold starts

Q: How do you fix fault code P0141?

STEP 1: Check fuses related to the 'Oxygen Sensor Heater' or 'Engine Management'. Inspect the sensor connector for corrosion or backed-out pins. STEP 2: Disconnect the sensor and measure resistance (Ohm) between the two heater wires (usually the same color, often white). Specs typically range from 5–20 Ohms. An 'Open' circuit (OL) confirms a dead heater element. STEP 3: Check for 12V power supply at the harness side of the connector with key on. Verify the ground side is being pulsed by the ECU (using a test light or oscilloscope). STEP 4: If the heater element is confirm failed, replace the downstream O2 sensor. Clear codes and perform a drive cycle.

Last updated:1 February 2026

Related:Oxygen Sensor (Bank 1 Sensor 2), ECU / Motorstyrdon, Oxygen sensor fuse, Exhaust system wiring harness

System

Powertrain (Engine & Gearbox)

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Technical Description

P0141 occurs when the Engine Control Unit (ECU) detects a failure in the heater circuit of the downstream oxygen sensor (Bank 1, Sensor 2). Standard O2 sensors need to reach operating temperature (approx. 600°F) to generate a reliable voltage signal. To achieve this quickly, the ECU pulses a dedicated heater circuit (often via PWM). If the ECU detects an open circuit, high resistance, or a short circuit in the heater element's wiring or the element itself, the code is stored. This prevents the monitor for catalyst efficiency from running.

Possible Causes

Failed heater element inside the oxygen sensor (Bank 1, Sensor 2)

Corrosion or poor connection in the sensor connector

Wiring harness damage (rubbing against exhaust or chassis)

Blown fuse for the O2 heater circuit or faulty relay

Internal ECU failure

Symptoms

Check Engine Light (MIL) illumination

Failed emissions test

Slightly increased fuel consumption during warm-up phase VIDA.

Increased tailpipe emissions during cold starts

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P0141 - O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)

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P0141 - O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)

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