DTC P2251:00 [MZR 2.3 DISI Turbo]

id0102g4851300

DTC P2251:00

A/F sensor negative current control circuit open

DETECTION CONDITION

•  The PCM monitors the A/F sensor terminal 1C voltage. If either of the following conditions are met, the PCM determines that the A/F sensor negative current control circuit is open.

MONITORING CONDITIONS

―  The A/F sensor element impedance specified or more.

―  Circuit voltage oscillation or A/F sensor terminal 1C voltage is below the specified.

―  The PCM detects the DTC P0134:00 while the pending code P2251:00 is stored.

Diagnostic support note

•  This is a continuous monitor (A/F sensor, HO2S).

•  The MIL illuminates if the PCM detects the above malfunction 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 the PCM detects the above malfunction condition during first drive cycle.

•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

•  The DTC is stored in the PCM memory.

POSSIBLE CAUSE

•  A/F sensor connector or terminals malfunction

•  PCM connector or terminals malfunction

•  Open circuit in wiring harness between A/F sensor terminal 1B and PCM terminal 2AC

•  A/F sensor malfunction

―  A/F sensor heater cannot be controlled.

•  PCM malfunction

DTC P2251:00	A/F sensor negative current control circuit open
DETECTION CONDITION	• The PCM monitors the A/F sensor terminal 1C voltage. If either of the following conditions are met, the PCM determines that the A/F sensor negative current control circuit is open. MONITORING CONDITIONS ― The A/F sensor element impedance specified or more. ― Circuit voltage oscillation or A/F sensor terminal 1C voltage is below the specified. ― The PCM detects the DTC P0134:00 while the pending code P2251:00 is stored. Diagnostic support note • This is a continuous monitor (A/F sensor, HO2S). • The MIL illuminates if the PCM detects the above malfunction 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 the PCM detects the above malfunction condition during first drive cycle. • FREEZE FRAME DATA (Mode 2)/Snapshot data is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• A/F sensor connector or terminals malfunction • PCM connector or terminals malfunction • Open circuit in wiring harness between A/F sensor terminal 1B and PCM terminal 2AC • A/F sensor malfunction ― A/F sensor heater cannot be controlled. • PCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA (MODE 2) • Perform the Freeze Frame PID Data Access Procedure. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) • Is the DTC P2251:00 on FREEZE FRAME DATA (Mode 2)?	Yes	Go to the next step.
1		No	Go to the troubleshooting procedures for DTC on FREEZE FRAME DATA (Mode 2). (See DTC TABLE [MZR 2.3 DISI Turbo].)
2	VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED • Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor, HO2S related) been recorded?	Yes	Go to the next step.
2		No	Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
3	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.
3		No	Go to the next step.
4	VERIFY RELATED PENDING CODE AND/OR DTC • Switch the ignition to off, then to ON (engine off). • Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) • Is the PENDING CODE/DTC P0031:00 or P0032:00 also present?	Yes	Go to the applicable PENDING CODE or DTC inspection. (See DTC P0031:00 [MZR 2.3 DISI Turbo].) (See DTC P0032:00 [MZR 2.3 DISI Turbo].)
4		No	Go to the next step.
5	INSPECT A/F SENSOR CONNECTOR CONDITION • Switch the ignition 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 connector and/or terminals, then go to Step 9.
5		No	Go to the next step.
6	INSPECT PCM CONNECTOR CONDITION • 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 connector and/or terminals, then go to Step 9.
6		No	Go to the next step.
7	INSPECT A/F SENSOR NEGATIVE CURRENT CONTROL CIRCUIT FOR OPEN CIRCUIT • A/F sensor and PCM connectors are disconnected. • Inspect for continuity between A/F sensor terminal 1B (wiring harness-side) and PCM terminal 2AC (wiring harness-side). • Is there continuity?	Yes	Go to the next step.
7		No	Repair or replace the wiring harness for a possible open circuit, then go to Step 9.
8	INSPECT A/F SENSOR • Reconnect all disconnected connectors. • Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 2.3 DISI Turbo].) • Is there any malfunction?	Yes	Replace the A/F sensor, then go to the next step. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)
8		No	Go to the next step.
9	VERIFY DTC TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [MZR 2.3 DISI Turbo].) • Perform the KOER self test. (See KOEO/KOER SELF TEST [MZR 2.3 DISI Turbo].) • Is the PENDING CODE for this DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].) Go to the next step.
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [MZR 2.3 DISI Turbo].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR 2.3 DISI Turbo].)
10		No	DTC troubleshooting completed.