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Home >> Chevrolet >> 1995 >> Lumina Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 3.1L >> ECM/Pcm Code Charts >> Code 28, Trans. Range Pressure Switch >> Diagnostic Aids
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Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed-through wire insulation or wire broken inside insulation. Inspect PCM harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection and damaged harness. Monitor Tech 1 while moving related connectors and wiring harness. If failure is induced, reading will change. This may assist in isolating the location of the malfunction.

Fig 1: Code 28 Schematic (3.1L) Transmission Range Pressure Switch
G95J14018
Fig 2: Code 28 Diagnostic Flow Chart (3.1L) Transmission Range Pressure Switch
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