PRELIMINARY INSPECTION
Verify customer complaint by operating suspected system. Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. To test by symptom, see SYMPTOM TABLE .
| Symptom | Test |
|---|---|
| Scan Tool Will Not Communicate With Class 1 Data Line | A |
| Scan Tool Will Not Communicate With Components | B |
SYMPTOM
TEST A: SCAN TOOL WILL NOT COMMUNICATE WITH CLASS 1 DATA LINE
For testing procedure, refer to flowchart. (Scheme 1)
Scheme 1
TEST B: SCAN TOOL WILL NOT COMMUNICATE WITH COMPONENTS
For testing procedure, refer to flowchart. (Scheme 2)
