FixVault
Home › Chevrolet › 1995 › Corvette Base, 2D Convertible, Automatic › Repair and Diagnosis › Engine Performance › System › Engine Controls - Tests W/Codes › ECM/Pcm Code Charts › Code 91, 1-4 Upshift Light › Test Description

Test Description

NOTE: Test numbers refer to numbers on diagnostic chart.
  1. The 1-4 upshift light should not turn on. If light is on, circuit is shorted to ground or PCM is faulty.
  2. PCM should turn on 1-4 upshift light.
  3. Checks 1-4 upshift light circuit up to PCM connector. If light illuminates, PCM connector is faulty or PCM does not have ability to ground circuit.
Fig 1: Code 91 Schematic (Corvette) 1-4 Upshift Light
G95F14378
Fig 2: Code 91 Diagnostic Flow Chart (Corvette) 1-4 Upshift Light
G94I35178
About FixVault