DTC P0036-12: HO2S Heater Control Circuit Bank 1 Sensor 2 Circuit Short to Battery; DTC P0036-14: HO2S Heater Control Circuit Bank 1 Sensor 2 Circuit Short to Ground or Open; DTC P0056-12: HO2S Heater Control Bank 2 Sensor 2 Circuit Short to Battery; DTC P0056-14: HO2S Heater Control Bank 2 Sensor 2 Circuit Short to Ground or Open; DTC P0141-18: O2 Sensor Heater Circuit Bank 1 Sensor 2 Circuit Current Below Threshold; DTC P0161-18: O2 Sensor Heater Circuit Bank 2 Sensor 2 Circuit Current Below Threshold; DTC P102A-9E: O2 Sensor Heater Performance Bank 1 Sensor 2 Stuck On; DTC P105A-9E: O2 Sensor Heater Performance Bank 2 Sensor 2 Stuck On [12/2019 - 10/2022]: Description
In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC (Three-Way Catalytic Converter) is used. For the most efficient use of the TWC, the air fuel ratio must be precisely controlled so that it is always close to the stoichiometric air fuel level. For the purpose of helping the ECM to deliver accurate air fuel ratio control, a heated oxygen sensor is used.
The heated oxygen sensor is located behind the TWC, and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low).
When the air fuel ratio becomes lean, the oxygen concentration in the exhaust gas is high. The heated oxygen sensor informs the ECM that the post-TWC air fuel ratio is lean (low voltage, i.e. less than 0.45 V).
Conversely, when the air fuel ratio is richer than the stoichiometric air fuel level, the oxygen concentration in the exhaust gas is low. The heated oxygen sensor informs the ECM that the post-TWC air fuel ratio is rich (high voltage, i.e. higher than 0.45 V). The heated oxygen sensor has the property of changing its output voltage drastically when the air fuel ratio is close to the stoichiometric level.
The ECM uses the supplementary information from the heated oxygen sensor to determine whether the air fuel ratio after the TWC is rich or lean, and adjusts the fuel injection duration accordingly. Thus, if the heated oxygen sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air fuel ratio control.
HINT:
- When any of these DTCs are stored, the ECM enters fail-safe mode. The ECM turns off the heated oxygen sensor heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned off.
- The heated oxygen sensor heater circuit uses a relay on the +B side of the circuit.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory | Note |
|---|---|---|---|---|---|---|
| P0036-12 | HO2S Heater Control Circuit Bank 1 Sensor 2 Circuit Short to Battery | Heated oxygen sensor heater current reaches high limit (1 trip detection logic). |
|
Comes on | DTC stored | SAE Code: P0038 DTC for Mexico Models: - Applies |
| P0036-14 | HO2S Heater Control Circuit Bank 1 Sensor 2 Circuit Short to Ground or Open | Heated oxygen sensor heater current is the specified value or less while the heater is operating (1 trip detection logic). |
|
Comes on | DTC stored | SAE Code: P0037 DTC for Mexico Models: - Applies |
| P0056-12 | HO2S Heater Control Bank 2 Sensor 2 Circuit Short to Battery | Heated oxygen sensor heater current reaches high limit (1 trip detection logic). |
|
Comes on | DTC stored | SAE Code: P0058 DTC for Mexico Models: - Applies |
| P0056-14 | HO2S Heater Control Bank 2 Sensor 2 Circuit Short to Ground or Open | Heated oxygen sensor heater current is the specified value or less while the heater is operating (1 trip detection logic). |
|
Comes on | DTC stored | SAE Code: P0057 DTC for Mexico Models: - Applies |
| P0141-18 | O2 Sensor Heater Circuit Bank 1 Sensor 2 Circuit Current Below Threshold | The cumulative heater resistance correction value exceeds the threshold (2 trip detection logic). |
|
Comes on | DTC stored | SAE Code: P0141 DTC for Mexico Models: - Does not apply |
| P0161-18 | O2 Sensor Heater Circuit Bank 2 Sensor 2 Circuit Current Below Threshold | The cumulative heater resistance correction value exceeds the threshold (2 trip detection logic). |
|
Comes on | DTC stored | SAE Code: P0161 DTC for Mexico Models: - Does not apply |
| P102A-9E | O2 Sensor Heater Performance Bank 1 Sensor 2 Stuck On | Heated oxygen sensor heater current is higher than the specified value while the heater is not operating (1 trip detection logic). |
|
Comes on | DTC stored | SAE Code: P102D DTC for Mexico Models: - Applies |
| P105A-9E | O2 Sensor Heater Performance Bank 2 Sensor 2 Stuck On | Heated oxygen sensor heater current is higher than the specified value while the heater is not operating (1 trip detection logic). |
|
Comes on | DTC stored | SAE Code: P105D DTC for Mexico Models: - Applies |