LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2007 >> B9 Tribeca Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Diagnostic Trouble Code (DTC) Detecting Criteria (H6DO) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0172 System Too Rich (Bank 1) >> Diagnostic Method >> Abnormality Judgment
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Abnormality Judgment

Compare the diagnosed value (fsobd) with the threshold value, and if a condition where the malfunction criteria are met continues for more than 50 seconds, judge that there is a fault in the fuel system.

Judgment Value 

MALFUNCTION CRITERIA AND THRESHOLD VALUE REFERENCE

Malfunction Criteria Threshold Value
fsobd = (sglmd - tglmda) + fan + flaf ≥ fsobdR1
In this case: sglmd = measured lambda, tglmda = target lambda, fan = main feedback compensation coefficient (every 64 milliseconds), flaf = main feedback learning compensation coefficient Refer to . fsobdR1 = rich side threshold value of fsobd

Map 4 

MAP 4 THRESHOLD VALUE FOR FUEL SYSTEM MALFUNCTION CRITERIA

Amount of air (g (oz)/s) 0 (0) 3.2 (0.113) 6.4 (0.226) 9.6 (0.339) 12.8 (0.451) 16 (0.564) 19.2 (0.677)
fsobdR1 (%) -40 -40 -31.2 -26.5 -26.5 -26.5 26.5

Time Needed for Diagnosis:  10 seconds x 5 times

Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.