Subaru 2009 IMPREZA Service Manual page 785

Diagnostic Trouble Code (DTC) Detecting Criteria
7. GENERAL DRIVING CYCLE
Perform the diagnosis only once when deceleration fuel cut occurs after rapid acceleration. (Pay attention to
the oxygen sensor voltage for the timing of the deceleration.)
8. DIAGNOSTIC METHOD
When the oxygen sensor output voltage changes from 0.25 V (lean) to 0.55 V (rich), calculate the minimum
response time for output change between 0.3 V and 0.5 V for the judgement criteria.
Diagnosis execution condition
(A)
(B)
Rear oxygen sensor (V)
(C)
(D)
(E)
Fuel cut on deceleration
(A) 0.55 V
(B) 0.5 V
(C) 0.3 V
(D) 0.25 V
(E) 0 V
(F) More than 5 seconds
(H)
(F)
(G) More than 120000 ms
(H) Measure the response time (diag-
nostic value).
(I) Execute the malfunction judge-
ment in 2000 ms from the recov-
ery of fuel cut on deceleration.
GD(H4SO)-61
GENERAL DESCRIPTION
(G)
(I)
(J) Judge NG when the voltage of
rear oxygen sensor is 0.25 V or
less for 120000 ms or more after
recovery of fuel cut on decelera-
tion.
(J)
EN-05567