Diagnostic Aids

Code will set when an unknown gear ratio is detected for any gear but 4th. Check all connections, especially those at transmission pass-thru connector. If code is intermittent, see INTERMITTENTS in TESTS W/O CODES - GASOLINE article. Compare scan tester gear ratio reading to specifications in GEAR RATIO table.

Fig 1: Code 85 Schematic (All Models) Undefined Gear Ratio

Fig 2: Code 85 Flow Chart (All Models) Undefined Gear Ratio