DTC P2237 [LF ATX (FN4A-EL), L3 ATX]

id0102b6813100

DTC P2237

A/F sensor positive current control circuit open
DETECTION CONDITION
•  The PCM monitors A/F sensor positive current control circuit voltage. If the voltage is not changed against the PCM control value while the engine running, the PCM determines that the A/F sensor positive current control circuit is open.
Diagnostic support note
•  This is a continuous monitor (A/F sensor, HO2S).
•  The MIL illuminates if PCM detects the above malfunctioning condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
•  PENDING CODE is available if PCM detects the above malfunction conditions during the first drive cycle.
•  FREEZE FRAME DATA is available.
•  DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  A/F sensor malfunction
•  Connector or terminal malfunction
•  Open circuit between PCM terminal 2AD and A/F sensor terminal B
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA HAVE BEEN RECORDED
•  Have FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA
•  Is DTC P2237 on FREEZE FRAME DATA?
Yes
Go to the next step.
No
Go to troubleshooting for DTC on FREEZE FRAME DATA.
(SeeDTC TABLE [LF ATX (FN4A-EL), L3 ATX].)
4
INSPECT A/F SENSOR CONNECTOR FOR POOR CONNECTION
•  Turn the ignition switch to off.
•  Disconnect the A/F sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, and corrosion)
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 7.
No
Go to the next step.
5
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Turn the ignition switch to off.
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, and corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 7.
No
Go to the next step.
6
INSPECT A/F SENSOR POSITIVE CURRENT CIRCUIT FOR OPEN CIRCUIT
•  A/F sensor and PCM connectors disconnected.
•  Verify the continuity between PCM terminal 2AD and A/F sensor terminal B.
•  Is there continuity?
Yes
Replace the A/F sensor, then go to the next step.
No
Repair or replace wiring harness for open, then go to the next step.
7
VERIFY TROUBLESHOOTING OF DTC P2237 COMPLETED
•  Make sure to reconnect all disconnected
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the KOEO or KOER self-test.
•  Is the DTC P2237 present?
Yes
Replace PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [LF, L3].)
No
Go to the next step.
8
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [LF ATX (FN4A-EL), L3 ATX].)
No
Troubleshooting completed.