Express 1/2 Ton Van V8-305 5.0L VIN M SFI (1998)
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 the fuse is open, LOCATE and REPAIR cause of the overload and REPLACE the 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 as per the appropriate
manual sections (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 Section 9K.
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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 Troubleshooting
Procedures). See: Diagrams/Diagnostic Aids
