DTC P2251:00, P2254:00 [MZI-3.7 (PCM CONNECTOR (3 TYPES))]

id0102e4506200

DTC P2251:00

DTC P2254:00

P2251:00: A/F sensor (RH) negative current control circuit/open

P2254:00: A/F sensor (LH) negative current control circuit/open
DETECTION CONDITION
•  P2251:00 indicates that A/F sensor (RH) positive current control circuit/open
•  P2254:00 indicates that A/F sensor (LH) positive current control circuit/open
•  The powertrain control module (PCM) monitors the universal heated oxygen sensor (HO2S) for a circuit concern. This DTC sets when the PCM detects a concern with the circuit used to determine the oxygen content in the exhaust gas.
POSSIBLE CAUSE
•  Open A/F sensor circuit
•  P2251:00:
―  Open circuit in wiring harness between the following terminals:
•  A/F sensor (RH) terminal D—PCM terminal 2BD
•  A/F sensor (RH) terminal F—PCM terminal 2AG
•  A/F sensor (RH) terminal H—PCM terminal 2AC
―  Short to ground in wiring harness between the following terminals:
•  A/F sensor (RH) terminal D—PCM terminal 2BD
•  A/F sensor (RH) terminal F—PCM terminal 2AG
•  A/F sensor (RH) terminal G—PCM terminal 2AS
•  A/F sensor (RH) terminal H—PCM terminal 2AC
―  Short to power supply in wiring harness between the following terminals:
•  A/F sensor (RH) terminal D—PCM terminal 2BD
•  A/F sensor (RH) terminal F—PCM terminal 2AG
•  A/F sensor (RH) terminal G—PCM terminal 2AS
•  A/F sensor (RH) terminal H—PCM terminal 2AC
•  P2254:00:
―  Open circuit in wiring harness between the following terminals:
•  A/F sensor (LH) terminal D—PCM terminal 2BF
•  A/F sensor (LH) terminal F—PCM terminal 2AK
•  A/F sensor (LH) terminal H—PCM terminal 2AE
―  Short to ground in wiring harness between the following terminals:
•  A/F sensor (LH) terminal D—PCM terminal 2BF
•  A/F sensor (LH) terminal F—PCM terminal 2AK
•  A/F sensor (LH) terminal G—PCM terminal 2AO
•  A/F sensor (LH) terminal H—PCM terminal 2AE
―  Short to power supply in wiring harness between the following terminals:
•  A/F sensor (LH) terminal D—PCM terminal 2BF
•  A/F sensor (LH) terminal F—PCM terminal 2AK
•  A/F sensor (LH) terminal G—PCM terminal 2AO
•  A/F sensor (LH) terminal H—PCM terminal 2AE
•  Damaged A/F sensor
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record 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
VISUALLY INSPECT A/F SENSOR HARNESS
•  Turn the ignition switch off.
•  Disconnect the suspect A/F sensor connector.
•  Visually inspect suspect A/F sensor for:
―  Pinched, shorted, and corroded wiring and pins
―  Oil or water contamination
―  Crossed sensor wires
―  Damaged A/F sensor
•  Is a concern present?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 8.
No
Go to the next step.
4
CHECK UO2S, UO2SGREF AND UO2SPCT CIRCUITS FOR OPEN IN HARNESS
•  Suspect A/F sensor connector is disconnected.
•  Turn the ignition switch off.
•  Disconnect the PCM connector.
•  Measure the resistance between the following terminals (wiring harness-side):
―  P2251:00:
•  A/F sensor (RH) terminal D—PCM terminal 2BD
•  A/F sensor (RH) terminal F—PCM terminal 2AG
•  A/F sensor (RH) terminal H—PCM terminal 2AC
―  P2254:00:
•  A/F sensor (LH) terminal D—PCM terminal 2BF
•  A/F sensor (LH) terminal F—PCM terminal 2AK
•  A/F sensor (LH) terminal H—PCM terminal 2AE
•  Is the resistance less than 5 ohm?
Yes
Go to the next step.
No
Repair for open circuit, then go to Step 8.
5
CHECK UO2S, UO2SGREF, UO2SPC, AND UO2SPCT CIRCUITS FOR SHORT TO GROUND IN HARNESS
•  Suspect A/F sensor and PCM connectors are disconnected.
•  Measure the resistance between the following suspect A/F sensor terminals (wiring harness-side) and body ground:
―  P2251:00:
•  A/F sensor (RH) terminal D
•  A/F sensor (RH) terminal F
•  A/F sensor (RH) terminal G
•  A/F sensor (RH) terminal H
―  P2254:00:
•  A/F sensor (LH) terminal D
•  A/F sensor (LH) terminal F
•  A/F sensor (LH) terminal G
•  A/F sensor (LH) terminal H
•  Is the resistance greater than 10 kilohms?
Yes
Go to the next step.
No
Repair for short circuit, then go to Step 8.
6
CHECK UO2S, UO2SGREF, UO2SPC, AND UO2SPCT CIRCUITS FOR SHORT TO VOLTAGE IN HARNESS
•  Suspect A/F sensor and PCM connectors are disconnected.
•  Turn the ignition switch to the ON position (engine off).
•  Measure the voltage between the following suspect A/F sensor terminals (wiring harness-side) and body ground:
―  P2251:00:
•  A/F sensor (RH) terminal D
•  A/F sensor (RH) terminal F
•  A/F sensor (RH) terminal G
•  A/F sensor (RH) terminal H
―  P2254:00:
•  A/F sensor (LH) terminal D
•  A/F sensor (LH) terminal F
•  A/F sensor (LH) terminal G
•  A/F sensor (LH) terminal H
•  Is there any voltage?
Yes
Repair for short circuit, then go to Step 8.
No
Go to the next step.
7
CHECK UO2SGREF CIRCUIT FOR VOLTAGE
•  Turn the ignition switch off.
•  Reconnect the PCM connector.
•  Turn the ignition switch to the ON position (engine off).
•  Measure the voltage between suspect A/F sensor terminal F and body ground.
•  Is the voltage between 3.5—3.7 V?
Yes
Replace the A/F sensor, then go to the next step.
(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZI-3.7 (PCM CONNECTOR (3 TYPES))].)
No
Go to the next step.
(The system is operating normal at this time. The concern may have been caused by a loose or corroded connector.)
8
VERIFY TROUBLESHOOTING OF DTC P2251:00, P2254:00 HAS BEEN COMPLETED
•  Verify that all disconnected connectors are reconnected.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the KOER self-test.
•  Is the PENDING CODE for this DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
9
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZI-3.7 (PCM CONNECTOR (3 TYPES))].)
No
Troubleshooting completed.