P014100 – O2 Sensor Heater Circuit, Bank 1 Sensor 2, No Activity Detected.

✅ What P0141 Means

This code indicates a problem in the heater circuit of the Bank 1 Sensor 2 (downstream O₂ sensor).
The heater inside the sensor helps it reach operating temperature quickly. If the heater doesn’t work, the sensor stays “cold” and shows no activity.

🔧 Common Causes

1. Failed O₂ Sensor (Heater Element Burnt) – Most common

Heater element inside the sensor is open/short.

2. Wiring Issues

Broken wires

Melted wires near exhaust

Corroded or loose connector pins

3. Blown O2 Sensor Heater Fuse

Some cars have a dedicated fuse for O2 heater circuits.

4. Poor Ground

Weak ground circuit to heater side.

5. ECM Driver Fault (RARE)

🧰 Step-by-Step Diagnosis

1. Visual Inspection

Locate Bank 1 Sensor 2 (after the catalytic converter).

Check:

Wiring touching hot exhaust

Melted insulation

Loose / corroded connector

Water ingress

If damage found → repair and clear code.

2. Check Heater Fuse

Look for the fuse labeled:

O2 HTR

AFS Heater

EFI 2

ENG 2 (varies by vehicle)

If blown → Replace.
If it blows again → wiring short in heater circuit or sensor.

3. Heater Resistance Test

Unplug sensor → Measure resistance across heater pins.

Typical value:

3–15 ohms (varies by brand)

🔹 0 ohms → internal short → Replace sensor
🔹 Infinite (OL) → heater open → Replace sensor

4. Check Power Supply (with ignition ON)

At the connector vehicle side:

One pin should have battery voltage (12V)

One pin is ECU-controlled ground

If no voltage → check fuse / wiring
If no ground switching → wiring or ECU driver fault

5. Replace Sensor (If confirmed)

If heater is faulty → replace Bank 1 Sensor 2.

After replacement:

Clear codes

Perform a short road test

🚗 Symptoms Customer May Notice

Check Engine Light

Slight increase in fuel consumption

Vehicle still runs normally (because it’s downstream sensor)

🛠 Recommended Fix Priority

1. Inspect wiring and connectors

2. Check heater fuse

3. Test heater resistance

4. Replace sensor if faulty

Welcome To Madurai Car Service 💐🙏.