Diagnostic Aids

DTC 85 will set when an unknown gear ratio is detected for any gear except 4th gear. See GEAR RATIO table for commanded gear and ratio range.

Fig 1: DTC 85 Schematic - 1994 Diesel

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC 85 Schematic - 1994 Gasoline

Courtesy of GENERAL MOTORS CORP.

Fig 3: DTC 85 Flow Chart - 1994

Courtesy of GENERAL MOTORS CORP.