G 2500 3/4 Ton Van V8-305 5.0L VIN M SFI (1997)
Information Bus: Initial Inspection and Diagnostic Overview
1. CHECK Scan Tool operation on a known good vehicle to make sure tool is operating properly.
2. CHECK condition of PWR AUX Fuse 7. If fuse is open, LOCATE and REPAIR cause of overload and REPLACE fuse.
3. CHECK that Grounds G101, G103 and G201 are clean and tight.
4. The following diagnostics assume that a communications failure is initially established during testing with the scan tool. (Engine Controls,
Antilock Brakes, Power Steering Gear and Pump, or Supplemental Inflatable Restraints) or that the Remote Control Door Lock Receiver did not
respond to programming attempts as per Keyless Entry. See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Keyless Entry
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Check for a broken (or partially broken) wire inside the insulation which could cause system malfunction but prove GOOD in a continuity/voltage
check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should be checked by monitoring
for a voltage drop with the system operational (under load).
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Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems (Refer to "General
Troubleshooting Procedures,"). See: Diagrams/Diagnostic Aids
