Diagnostic Aids

Check all connections, especially at transmission pass-thru connector. An open in the ignition feed circuit may cause multiple DTC's to set.

Fig 1: DTC 81 Schematic - 1994 Diesel

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC 81 Schematic - 1994 Gasoline

Courtesy of GENERAL MOTORS CORP.

Fig 3: DTC 81 Flow Chart - 1994

Courtesy of GENERAL MOTORS CORP.