Diagnostic Aids

A slow unstable idle may be caused by a system problem which cannot be overcome by IAC valve. Scan tester counts will be more than 60 counts if too low and zero counts if too high.

Check the following to repair a non-IAC system problem:

• Vacuum Leak
• Lean Heated Oxygen Sensor Signal
• Rich Heated Oxygen Sensor Signal
• Throttle Body
• IAC Valve Electrical Connections
• PCV Valve

Fig 1: Chart C-2C - Schematic

Courtesy of ISUZU MOTOR CO.

Fig 2: Chart C-2C - Diagnostic Flowchart

Courtesy of ISUZU MOTOR CO.