DTC Advanced Diagnostics: P2271 (2.0L Engine) (2024 2025)
DTC P2271 : Secondary Heated Oxygen Sensor (Secondary HO2S (Sensor 2)) Circuit Signal Stuck Rich
General Description
The range check during target lean/rich operation is utilized to provide monitoring of the secondary heated oxygen sensor (secondary HO2S (sensor 2)) in order to detect deterioration of the sensor. During the enleanment/enrichment of the air/fuel mixture by the active test once the target lean/rich value has been reached, the secondary HO2S (sensor 2) voltage is monitored against rationality threshold. If the secondary HO2S (sensor 2) voltage is a specified value during the enleanment/enrichment of the air/fuel mixture by the active test, the powertrain control module (PCM) detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | 0.5 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum | |
|---|---|---|---|
| Time not in fuel cut-off operation | 10 seconds | - | |
| Outside air temperature | -54 deg.F (-48 deg.C) | - | |
| Engine coolant temperature [ECT sensor 1] | -54.47 deg.F (-48.04 deg.C) | - | |
| Catalyst temperature | 842 deg.F (450 deg.C) | - | |
| Engine speed [Engine Speed] | 1, 200 rpm | 4, 520 rpm | |
| Vehicle speed [Vehicle Speed] | 0 mph (0 km/h) | - | |
| Relative air charge | 15 % to 22 % | - | |
| Other | Exhaust gas mass flow is stable for at least 1 second | ||
| Actual secondary HO2S (sensor 2) heater temperature is around set point temperature | |||
| Following table A must be met for more than 0.08 kg (0.18 lbs) of integrated exhaust gas mass flow | |||
| Canister not purging | |||
| No gear shifting | |||
Table A
| Condition | Minimum | Maximum | |
|---|---|---|---|
| Catalyst bed temperature | 842 deg.F (450 deg.C) | 1, 562 deg.F (850 deg.C) | |
| Exhaust gas mass flow* 1 | 30 kg/h | 200 kg/h | |
| Exhaust gas mass flow* 1 | 20 kg/h | 200 kg/h | |
| Commanded lambda | 0.97 | 1.03 | |
| Other | Catalyst bed temperature is stable | ||
*1: USA/Canada models
*2: Mexico models
[ ]: HDS Parameter
Malfunction Threshold
All of the conditions occur:
- Lambda request for active test (target lean) is 1.13 or more.
- Integrated exhaust gas mass flow at catalyst input after lambda request for active test is 0.08 kg (0.2 lbs) or more.
- Minimum secondary HO2S (sensor 2) voltage is more than 0.2 V.
Possible Cause
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) rich stuck
Confirmation Procedure
Operating Condition
- Start the engine. Hold the engine speed [Engine Speed] at 3, 000 rpm without load (in neutral) until the radiator fan comes on.
- Drive the vehicle at constant vehicle speed with part load.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
Diagnosis Details
Conditions for setting the DTC
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, the freeze data, and the on-board snapshot 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, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.