DTC P2251-00; Open Circuit Between A/F Sensor Terminal D And Pcm Terminal 1C: Notes

NOTE:

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

Details On DTCs

DETECTION CONDITION AND POSSIBLE CAUSE

DESCRIPTION	Open circuit between A/F sensor terminal D and PCM terminal 1C
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, P0032:00 A/F sensor terminal F voltage (B+ terminal) is unstable: Internal PCM malfunction: P064D:00
	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	Illuminates check engine light.
POSSIBLE CAUSE	A/F sensor connector or terminals malfunction PCM connector or terminals malfunction Open circuit in wiring harness between A/F sensor terminal D and PCM terminal 1C A/F sensor malfunction PCM malfunction
(1) Value can be verified by displaying PIDs using M-MDS

System Wiring Diagram

Fig 1: A/F Sensor Wiring Harness-Side Connector Terminals

Courtesy of MAZDA MOTORS CORP.