Troubleshooting

DTC P2240 OXYGEN SENSOR PUMPING CURRENT CIRCUIT/OPEN (FOR A/F SENSOR) (BANK 2 SENSOR 1)

CIRCUIT DESCRIPTION

DTC Detecting Condition:

A thermistor built in the water temperature sensor changes the resistance value according to the water temperature.

The structure of the sensor and connection to the ECM is the same as the those of the air temperature sensor.

HINT:
- P2237 means malfunction of bank 1 A/F sensor circuit.
- P2240 means malfunction of bank 2 A/F sensor circuit.
- Bank 1 refers to the bank that includes cylinder No.1.
- Bank 2 refers to the bank that includes cylinder No.2.
- Sensor 1 refers to the sensor closest to the engine body.
- After confirming DTC P2237, use the OBD II scan tool or hand-held tester to confirm voltage output of A/F sensor (AFS B1 S1/O2S B1 S1) from the CURRENT DATA.
- The A/F sensor's output voltage and the short-term fuel trim value can be read using the OBD II scan tool or hand-held tester.
- The ECM controls the voltage of the AFR+, AFL+, AFR- and AFL- terminals of the ECM to the fixed voltage. Therefore, it is impossible to confirm the A/F sensor output voltage without the OBD II scan tool or hand-held tester.
- The OBD II scan tool (excluding hand-held tester) displays the one - fifth of the A/F sensor output voltage which is displayed on the hand-held tester.

Wiring Diagram:

Step 1 - 2:

Step 2 (continued):

INSPECTION PROCEDURE

HINT:
- If DTC P2237 is displayed, check the bank 1 sensor 1 circuit.
- If DTC P2240 is displayed, check the bank 2 sensor 1 circuit.
- Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when the malfunction is detected. When troubleshooting, this is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.