Diagnostic Aids

If engine is allowed to cool overnight, coolant temperature and Manifold Air Temperature (MAT) should read nearly the same with scan tester. A Code 23A results if an open is present in circuit No. 452 or 472. For intermittent inspection, see INTERMITTENTS in TROUBLE SHOOTING -NO CODES - FUEL INJECTION article.

Fig 1: Code 23A - Schematic

Courtesy of ISUZU MOTOR CO.

Fig 2: Code 23A - Diagnostic Flowchart

Courtesy of ISUZU MOTOR CO.