Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P0141
DTC P0141:Â Secondary Heated Oxygen Sensor (Secondary HO2S (Sensor 2)) Heater Circuit Malfunction
General DescriptionÂ
A heater for the zirconia element is embedded in the secondary heated oxygen sensor (secondary HO2S (sensor 2)), and it is controlled by the powertrain control module (PCM). When activated, it heats the sensor to stabilize and speed up the detection of oxygen content when the exhaust gas temperature is cold. If the secondary HO2S (sensor 2) heater draws other than a specified amperage, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type, OBD StatusÂ
| Execution | Continuous |
| Sequence | None |
| Duration | 5.0 seconds or more |
| DTC Type | Two drive cycles, MIL on |
| OBD Status | PASSED/FAILED/NOT COMPLETED (STILL TESTING) |
Enable ConditionsÂ
| Condition | Minimum | Maximum |
|---|---|---|
| Engine coolant temperature [ECT SENSOR 1] | 41 deg. F (5 deg. C) | - |
| 12 volt battery voltage [BATTERY] (FI MAIN RLY OUT terminal of PCM) | 4.67 V | - |
| State of the engine | Running | |
| No active DTCs set (prevents monitor from running) | P0117, P0118 | |
[ ]: HDS Parameter
Malfunction ThresholdÂ
The secondary HO2S (sensor 2) heater output is 0.38 A or less, or 3.33 A or more, for at least 5.0 seconds when the heater is on.
Possible CauseÂ
NOTE:Â The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- Secondary HO2S (sensor 2) heater failure
- Secondary HO2S (sensor 2) SO2HT line open
- Secondary HO2S (sensor 2) SO2HT line short to ground
- Secondary HO2S (sensor 2) heater power supply line open (includes fuse blown)
- Secondary HO2S (sensor 2) heater internal circuit open
- Poor ignition switch
- PCM internal circuit failure
Confirmation ProcedureÂ
Operating ConditionÂ
Start the engine in a cold condition, and let it idle until the radiator fan comes on.
With the HDSÂ
None.
Diagnosis DetailsÂ
Conditions for setting the DTCÂ
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.
Conditions for clearing the DTCÂ
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.