Diagnostic Aids

DTC 85 will set when an unknown gear ratio is detected for any gear but 4th. Note commanded gear and incorrect ratio. Check transmission fluid level. Compare scan tester gear ratio reading to specifications in GEAR RATIO .

Fig 1: DTC 85 Schematic (4L80-E) Undefined Ratio Error

Fig 2: DTC 85 Flow Chart (4L80-E) Undefined Ratio Error