Fault codes

1991 GMC C3500
160,000 MILES • 0.7L • V8 • 4WD • AUTOMATIC
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STEVE GILL2
  • MEMBER
  • 1 POST
Want to see fault codes.
Sep 3, 2017 at 2:44 AM
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WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
If you jump terminals A and B of the diagnostic connector and turn the key on, the check engine light will flash code numbers.

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Sep 3, 2017 at 8:25 AM