Diagnostic Aids

Check for spread connectors at pass-thru connector. Code 68 will set when going to default (2nd gear). If code is intermittent, see INTERMITTENTS in TESTS W/O CODES - GASOLINE article.

Fig 1: Code 68 Schematic (All Models) Overdrive Ratio Error - 4L80-E Transmission

Fig 2: Code 68 Flow Chart (All Models) Overdrive Ratio Error - 4L80-E Transmission