Diagnostic Circuit Check: Notes
The Diagnostic Circuit Check will identify a problem created by an Electronic Engine Control System (EECS) malfunction. It must be the starting point for diagnosis, because it directs one to the next logical step in diagnosing the complaint.
After completing the diagnostic circuit check and finding the on-board diagnostics functioning properly and no trouble codes displayed, the appropriate "SCAN DATA" table may be used for comparison. The typical values are an average of display values recorded from normally operating vehicles and are intended to represent what a normally functioning system would typically display.
NOTE:
Only the parameters listed are used in this article for diagnosis. If a "Scan" tester reads other parameters, values are not recommended by Isuzu for use in diagnosis. A "Scan" tester that displays faulty data should not be used, and problem should be reported to manufacturer. Use of a faulty "Scan" tester can result in misdiagnosis and unnecessary parts replacement.
2.8L "SCAN" DATA
| "SCAN" Position | (1) Data Value | ||||||
|---|---|---|---|---|---|---|---|
| A/C | No (Yes W/A/C Requested) | ||||||
| Air Divert | Normal | ||||||
| Air Switch | Converter | ||||||
| Battery | 13.5-14.5 Volts | ||||||
| Block Learn | 118-138 Counts | ||||||
| Coolant Temperature | 185-221°F (85-105°C) | ||||||
| IAC | 1-50 Counts | ||||||
| Integrator | Varied Amount of Counts | ||||||
| Knock Signal | No | ||||||
| MAP | (2) 1-2 Volts | ||||||
| "Open/Closed" Loop | "Closed" Loop (Open At Idle) | ||||||
| Oxygen Sensor | (3) .1-.9 Volts | ||||||
| RPM | 550-750 RPM | ||||||
| TPS | .42-.54 Volts | ||||||
| VSS | 0 MPH | ||||||
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