Diagnostic Aids

1995 Chevrolet Blazer 4D Utility, AWDSECTION Diagnostic Aids

Code will set when an unknown gear ratio is detected for any gear but 4th. Check all connections, especially those at transmission pass-thru connector. If code is intermittent, see INTERMITTENTS in TESTS W/O CODES - GASOLINE article. Compare scan tester gear ratio reading to specifications in GEAR RATIO table.

GEAR RATIO

Gear Less Than More Than
1st 12.38 22.63
2nd 11.43 21.58
3rd 1.95 21.05
Reverse 11.97 22.17
Fig 1: Code 85 Schematic (4.3L) Undefined Gear Ratio
G95C28078
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.