Diagnostic Aids

Normal scan tester voltage varies between .1-1.0 volt while in closed loop. Code 13 sets in approximately one minute if voltage remains between .35-.55 volt, but system will enter open loop in approximately 15 seconds. For intermittent inspection, see INTERMITTENTS in H - EFI TEST W/O CODES article.

Fig 1: Code 13 - Schematic

Courtesy of ISUZU MOTOR CO.

Fig 2: Code 13 - Diagnostic Flowchart

Courtesy of ISUZU MOTOR CO.