LEMON Manuals: Even more car manuals for everyone
Home >> Subaru >> 2017 >> Forester 2.0XT Touring >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 16 (Engine Control System (Diagnostics) (P000A To P015B) (H4DO)) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P014C A/F/O2 Sensor Slow Response - Rich To Lean Bank 1 Sensor 1 >> Diagnostic Method 1

Diagnostic Method 1

WARNING: This page is about a different variant/trim than selected.

Detect the malfunction by checking "Cumulative value of time when λ changes from lean → rich" in comparison to "Time during which diagnosis is in progress".

Fig 1: Cumulative Value Timing Graph
G11272738Courtesy of SUBARU OF AMERICA, INC.

Judge as NG when the following conditions are established.

JUDGMENT VALUE SPECIFICATION

Malfunction Criteria Threshold Value DTC
Cumulative value of time when λ changes from lean → rich)/(Time during which diagnosis is in progress) < 0.22 P014C
Average value of time necessary for λ to inverse the air fuel ratio to Lean → Rich → Lean > 30ms
Cumulative value of time when λ changes from lean → rich)/(Time during which diagnosis is in progress) > 0.7 P014D
Average value of time necessary for λ to inverse the air fuel ratio to Rich → Lean → Rich > 10ms

Time needed for diagnosis:  70000ms

Malfunction indicator light illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.

6. DIAGNOSTIC METHOD 2 

Detect the malfunction by the cumulative value obtained from the amount of variation in λ change.

Fig 2: Malfunction Indicator Light Diagnostic Method
G08317431Courtesy of SUBARU OF AMERICA, INC.
JUDGMENT VALUE SPECIFICATION

Malfunction Criteria Threshold Value DTC
Cumulative value obtained from the amount of variation in λ change < Value from Map P014C and P014D

Map

MAP SPECIFICATION (AT MODEL)

Cumulative value obtained from the amount of variation in λ 0.00 3.50
Cumulative value obtained from the amount of variation in λ change 0.00 3.50
MAP SPECIFICATION (MT MODEL)

Cumulative value obtained from the amount of variation in λ 0.00 3.50
Cumulative value obtained from the amount of variation in λ change 0.00 3.50

Time needed for diagnosis:  70000ms

Malfunction indicator light illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.