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DIAGNOSIS SYSTEM (ECM) EC-529 < SYSTEM DESCRIPTION > [VK56DE] C D E F G H I J K L M A EC N P O OK: Self-diagnosis is carried out and the result is OK. When all SRT related self-diagnoses show OK results in a single cycle (Ignition OFF-ON-OFF), the SRT will indicate “CMPLT”. → Case 1 above When all SRT related self-diagnoses show OK results through several different cycles, the SRT will indicate “CMPLT” at the time the respective self-diagnoses have at least one OK result. → Case 2 above If one or more SRT related self-diagnoses show NG results in 2 consecutive cycles, the SRT will also indicate “CMPLT”. → Case 3 above The table above shows that the minimum number of cycles for setting SRT as “INCMP” is the number one (1) for each self-diagnosis (Case 1 & 2) or the number two (2) for one of self-diagnoses (Case 3). However, in preparation for the state emissions inspection, it is unnecessary for each self-diagnosis to be executed twice (Case 3) for the following reasons: • The SRT will indicate “CMPLT” at the time the respective self-diagnoses have one (1) OK result. • The emissions inspection requires “CMPLT” of the SRT only with OK self-diagnosis results. • During SRT driving pattern, the 1st trip DTC (NG) is detected prior to “CMPLT” of SRT and the self-diagnosis memory must be erased from the ECM after repair. • If the 1st trip DTC is erased, all the SRT will indicate “INCMP”. NOTE: SRT can be set as “CMPLT” together with the DTC(s). Therefore, DTC check must always be carried out prior to the state emission inspection even though the SRT indicates “CMPLT”. DIAGNOSIS DESCRIPTION : Permanent Diagnostic Trouble Code (Permanent DTC) INFOID:0000000007799374 Permanent DTC is defined in SAE J1979/ISO 15031-5 Service $0A. ECM stores a DTC issuing a command of turning on MIL as a permanent DTC and keeps storing the DTC as a permanent DTC until ECM judges that there is no presence of malfunction. Permanent DTCs cannot be erased by using the erase function of CONSULT or Generic Scan Tool (GST) and by disconnecting the battery to shut off power to ECM. This prevents a vehicle from passing the in-use inspec- tion without repairing a malfunctioning part. When not passing the in-use inspection due to more than one permanent DTC, permanent DTCs should be erased, referring to this manual. NOTE: • The important items in in-use inspection are that MIL is not ON, SRT test items are set, and permanent DTCs are not included. • Permanent DTCs do not apply for regions that permanent DTCs are not regulated by law. Self-diagnosis result Example Diagnosis Ignition cycle ← ON → OFF ← ON → OFF ← ON → OFF ← ON → All OK Case 1 P0400 OK (1) — (1) OK (2) — (2) P0402 OK (1) — (1) — (1) OK (2) P1402 OK (1) OK (2) — (2) — (2) SRT of EGR “CMPLT” “CMPLT” “CMPLT” “CMPLT” Case 2 P0400 OK (1) — (1) — (1) — (1) P0402 — (0) — (0) OK (1) — (1) P1402 OK (1) OK (2) — (2) — (2) SRT of EGR “INCMP” “INCMP” “CMPLT” “CMPLT” NG exists Case 3 P0400 OK OK — — P0402 — — — — P1402 NG — NG NG (Consecutive NG) (1st trip) DTC 1st trip DTC — 1st trip DTC DTC (= MIL ON) SRT of EGR “INCMP” “INCMP” “INCMP” “CMPLT” August 2012 2012 Pathfinder |