DTC Advanced Diagnostics: P2239: General Description

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

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. 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. 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 AFCB1 is shorted to power, the terminal voltage shows abnormal value. If the AFCB1 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