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DTC P2251:00 [PCM (SKYACTIV-G (US))]

DTC P2251:00 [PCM (SKYACTIV-G (US))]

SM2565569

id0102t48513u0

Note
• To determine the malfunctioning part, proceed with the diagnostics from “Function Inspection Using M-MDS”.



Details On DTCs

Description

Open circuit between A/F sensor terminal D and PCM terminal 1S
Detection condition
Determination conditions
• The following conditions are met:
― A/F sensor element impedance is specified value or more
― A/F sensor terminal F voltage (B+ terminal) is less than specified value or unstable.
Preconditions
• Battery voltage: 11—18 V *1
• A/F sensor is activated.
• The following DTCs are not detected:
― A/F sensor terminal F voltage (B+ terminal) is less than specified value:
• A/F sensor heater: P0031:00 and P0032:00
― A/F sensor terminal F voltage (B+ terminal) is unstable:
• Internal PCM malfunction: P064D:00
*1: Standard can be verified by displaying PIDs using M-MDS
Drive cycle
• 2
Self test type
• CMDTC self test, KOER self test
Sensor used
• A/F sensor
Fail-safe function
• Not applicable
Vehicle status when DTCs are output
• Not applicable
Possible cause
• A/F sensor connector or terminals malfunction
• PCM connector or terminals malfunction
• Open circuit in A/F sensor signal circuit
• A/F sensor malfunction
• PCM malfunction



Function Explanation (DTC Detection Outline)

• If the PCM detects an open circuit in the wiring harness between A/F sensor terminal D and PCM terminal 1S (COM wiring harness), it stores a DTC. In addition, when there is an open circuit in the wiring harness between A/F sensor terminal D and PCM terminal 1S (COM wiring harness), the A/F sensor terminal F (B+ terminal) becomes unstable. At this time, the PCM determines an open circuit in the wiring harness (COM wiring harness) between A/F sensor terminal D and PCM terminal 1S and stores a DTC.
• If the A/F sensor does not activate, monitoring cannot occur because the A/F sensor element has an insulation property which keeps it at a specific temperature range or less.



Repeatability Verification Procedure

1. Warm up the engine to allow the engine coolant temperature to reach 80 °C {176 °F} or more.
2. Start the engine and leave it idling for 1 min.

Note
• Match the engine coolant temperature in the recorded freeze frame data/snapshot data, the vehicle speed, and engine speed values to the best extent possible while driving the vehicle.
3. Try to reproduce the malfunction by driving the vehicle for 5 min based on the values in the freeze frame data/snapshot data.



PID Item/Simulation Item Used In Diagnosis

PID/DATA monitor item table

PIDs

Reference
A/F_SEN_CUR
(See PID/DATA MONITOR TABLE [PCM (SKYACTIV-G (US))].)



Function Inspection Using M-MDS

Step

Inspection

Results

Action
1
PURPOSE: VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY
• Verify related Service Bulletins, on-line repair information, or Service Information availability.
• Is any related Information available?
Yes
Perform repair or diagnosis according to the available information.
• If the vehicle is not repaired, go to the next step.
No
Go to the next step.
2
PURPOSE: RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION
• Record the freeze frame data/snapshot data and diagnostic monitoring test results (A/F sensor, HO2S related).

Note
• Recording can be facilitated using the screen capture function of the PC.
—
Go to the next step.
3
PURPOSE: INSPECT A/F SENSOR CONNECTOR FOR MALFUNCTION
• Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.)
• Are the connector and terminal normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location.
Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.
4
PURPOSE: INSPECT PCM CONNECTOR FOR MALFUNCTION
• Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.)
• Are the connector and terminal normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location.
Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.
5
PURPOSE: INSPECT A/F SENSOR SIGNAL CIRCUIT FOR OPEN CIRCUIT
• Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION.)
• Is the circuit normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location.
Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.
6
PURPOSE: DETERMINE INTEGRITY OF A/F SENSOR
• Start the engine and warm it up completely.
• Access the A/F_SEN_CUR PID using the M-MDS. (See PID/DATA MONITOR INSPECTION.)
• Drive the vehicle under the following conditions.

Warning
• When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
• While performing this step, always operate the vehicle in a safe and lawful manner.
― After increasing the engine speed to 3,000 rpm, decelerate using engine braking.
• Is the displayed PID value as follows?
― A/F_SEN_CUR: 0.25 mA or more
Yes
Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.
No
Go to the next step.
7
PURPOSE: VERIFY CONNECTOR CONNECTIONS
• Access the A/F_SEN_CUR PID using the M-MDS. (See PID/DATA MONITOR INSPECTION.)
• Does the PID value fluctuate when the following connectors are shaken?
― A/F sensor
― PCM
Yes
Repair or replace the applicable wiring harness or connector parts.
Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.
No
Replace the A/F sensor.
(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G (WITH CYLINDER DEACTIVATION (US))].)
(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US))].)
Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.



Troubleshooting Diagnostic Procedure

Intention of troubleshooting procedure
• Repair completion verification
― Verify that the primary malfunction is resolved and there are no other malfunctions.

Step

Inspection

Results

Action
Repair completion verification 1
PURPOSE: VERIFY THAT VEHICLE IS REPAIRED
• Install/connect the part removed/disconnected during the troubleshooting procedure.
• Clear the DTC recorded in the memory. (See CLEARING DTC.)
• Replicate the vehicle conditions at the time the DTC was detected using the following procedure.
― Perform the KOER self test. (See DTC INSPECTION.)
• Perform the DTC inspection for the PCM. (See DTC INSPECTION.)
• Is the same Pending DTC present?
Yes
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(US)].)
If the CAN communication is normal, perform the diagnosis from Step 1.
• If the malfunction recurs, replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (WITH CYLINDER DEACTIVATION (US))].) (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US))].)
No
Go to the next step.
Repair completion verification 2
PURPOSE: VERIFY IF OTHER DTCs DISPLAYED
• Perform the DTC inspection. (See DTC INSPECTION.)
• Are any other DTCs displayed?
Yes
Repair the malfunctioning location according to the applicable DTC troubleshooting.
No
DTC troubleshooting completed.