What Does P0141 Mean?
The ECM has detected a malfunction in the heater circuit of the Bank 1 Sensor 2 (downstream) oxygen sensor. The O2 sensor heater is essential for bringing the sensor to its operating temperature quickly after cold start and maintaining it there during low-exhaust-temperature conditions such as idle. Without proper heater operation, the sensor is slow to activate and may provide inaccurate readings. The driver may not notice any symptoms, though readiness monitors may not complete.
Common Causes
35%
Failed O2 sensor internal heater element (open circuit)
20%
Blown O2 sensor heater fuse
20%
Corroded or damaged O2 sensor connector affecting heater circuit pins
15%
Open or high-resistance wiring in the heater power or ground circuit
10%
ECM heater driver circuit failure (unable to provide heater ground)
Diagnostic Steps
1
Check the O2 sensor heater fuse — if blown, replace and check heater resistance before starting the engine. A shorted heater will blow the fuse again immediately.
2
Measure the O2 sensor heater resistance across the heater pins at the sensor connector. Expected range is 2-15 ohms depending on the manufacturer. An open reading (infinite ohms) means the heater element has failed.
3
Verify battery voltage is reaching the heater power pin at the O2 sensor connector with the key on. If no voltage, trace the power supply circuit through the fuse and relay.
4
Check the heater ground circuit. On many vehicles, the ECM controls the heater ground via a PWM driver. Verify the ECM is commanding the heater on by backprobing the ground control wire.
5
If the sensor heater resistance is out of spec, replace the O2 sensor. If the heater resistance is good but there is no power or ground, repair the wiring or fuse.
Estimated Repair Cost
$75 - $300
Parts + labor, varies by vehicle and location
The ECM has detected a malfunction in the heater circuit of the Bank 1 Sensor 2 (downstream) oxygen sensor. The O2 sensor heater is essential for bringing the sensor to its operating temperature quickly after cold start and maintaining it there during low-exhaust-temperature conditions such as idle....
The most common cause of P0141 (O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)) is: Failed O2 sensor internal heater element (open circuit)
Typical repair costs for P0141 range from $75 to $300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive. The O2 sensor heater mainly affects cold-start emissions performance and readiness monitor completion. No driveability concerns. Will cause emissions test failure.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0141 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions / Exhaust
Difficulty
Type
Generic (SAE)
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