DTC Advanced Diagnostics: P2249
DTC P2249:Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VCENT Circuit Low Voltage

General Description

The front air/fuel ratio (A/F) sensor (bank 2, sensor 1) is installed in the exhaust manifold and detects oxygen content in the exhaust gas. The front A/F sensor (bank 2, 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 front A/F sensor (bank 2, sensor 1) signal. When the self diagnosis function in the PCM detects a short circuit failure, the heater stops, and if the condition continues for a specified time, the PCM detects VCENTB2 short to ground and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status
Execution
Continuous
Sequence
None
Duration
5 seconds or more
DTC Type
Two drive cycles, MIL on
OBD Status
PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions
Condition
Minimum
Maximum
Battery voltage [BATTERY]
9.0 V
–
State of the engine
Running
No active DTCs set (prevents monitor from running)
P0155, P2240, P2241, P2247, P2254, P2255
[ ]: HDS Parameter

Malfunction Threshold
The PCM detects VCENTB2 short to ground after the self diagnosis function in the PCM judges as an occurrence of short circuit for 5 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.
Front A/F sensor (bank 2, sensor 1) failure
Front A/F sensor (bank 2, sensor 1) VCENTB2 line short to ground
PCM internal circuit failure

Confirmation Procedure
Operating Condition
Start the engine. Hold the engine speed [ENGINE SPEED] at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

With the HDS
None.

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 and the freeze data 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, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.