Advanced Diagnostics

Advanced Diagnostics - DTC P0141: Secondary Heated Oxygen Sensor (Secondary HO2S (Sensor 2)) Heater Circuit Malfunction (Engine Type: K24Z7)

General Description






A heater for the zirconia element is embedded in the secondary heated oxygen sensor (secondary HO2S (sensor 2)), and it is controlled by the engine control module (ECM). 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 heater draws other than a specified amperage, the ECM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
The secondary HO2S 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 Cause

NOTE: 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 heater failure
- Secondary HO2S SO2HT line open
- Secondary HO2S SO2HT line short to ground
- Secondary HO2S heater power supply line open (includes fuse blown)
- Secondary HO2S heater internal circuit open
- Poor ignition switch
- ECM internal circuit failure

Confirmation Procedure

With the HDS
None.

With the Driving Pattern
Start the engine in a cold condition, and let it idle until the radiator fan comes on.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the ECM 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 DTC
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 battery.