DTC Advanced Diagnostics: P0139 (3.0L Engine)

DTC P0139: Secondary Heated Oxygen Sensor (Secondary HO2S (Sensor 2)) Slow Response

General Description

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

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

The powertrain control module (PCM) determines the responsiveness of the secondary heated oxygen sensor (secondary HO2S (sensor 2)) by monitoring the secondary HO2S (sensor 2) output voltage change during the fuel cut-off control. If the changing of the secondary HO2S (sensor 2) output voltage takes time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Once per driving cycle
Sequence	None
Duration	-

DTC Type

Two drive cycles, MIL on

Enable Conditions

Condition	Minimum	Maximum
Secondary HO2S (sensor 2) element temperature	1, 022 deg.F (550 deg.C)	-
Secondary HO2S (sensor 2) output voltage before fuel cut-off*	0.62 V	-
Fuel feedback	During deceleration

*: Continue for more than 10 seconds

Malfunction Threshold

The secondary HO2S (sensor 2) output voltage change (changes from 0.6 V to 0.3 V) during the fuel cut-off takes more than 2.0 seconds.

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 (sensor 2) failure

Confirmation Procedure

Operating Condition

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

Start the engine. Hold the engine speed [Engine Speed] at 3, 000 rpm without load (in P or N) until the radiator fan comes on.
Drive the vehicle at a steady speed between 55 - 75 mph (90 - 120 km/h) for at least 1 minute.
Decelerate with the throttle valve fully closed for at least 8 seconds.

[ ]: HDS Parameter

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.