DTC Advanced Diagnostics: P2252 (3.0L Engine)

DTC P2252: Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) AFV Circuit Low Voltage

General Description

Courtesy of HONDA, U.S.A., INC.

The rear air/fuel ratio (A/F) sensor (bank 1, sensor 1) is installed in the exhaust manifold and detects oxygen content in the exhaust gas. The rear A/F sensor (bank 1, sensor 1) transmits a signal to the powertrain control module (PCM), and the PCM controls fuel injection duration by comparing the target air/fuel ratio with the rear A/F sensor (bank 1, sensor 1) signal. The rear A/F sensor (bank 1, sensor 1) is composed of detection element, reference oxygen chamber, diffusion chamber, and heater, etc., and enables feedback control of all ranges. If the rear A/F sensor (bank 1, sensor 1) signal AFVB1 is shorted to ground, the terminal voltage shows abnormal value. If the AFVB1 terminal voltage is a set value for a specified duration, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	0.5 second or more
DTC Type	Two drive cycles, MIL on

Enable Conditions

Condition
Vehicle	ON mode

Malfunction Threshold

Either of the condition occurs:

The AFVB1 terminal voltage is 0.182 V or less for at least 0.5 second.
The AFVB1 terminal voltage is 3.6 - 4.89 V and the voltage between the AFVB1 and the AFCB1 terminal is 0.15 V or less for at least 0.5 second.

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.

Rear A/F sensor (bank 1, sensor 1) AFVB1 line short to ground
Rear A/F sensor (bank 1, sensor 1) AFVB1 line short to rear A/F sensor (bank 1, sensor 1) AFCB1 line

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.