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Suburban Transmission - Diagnostic Codes
The best way to explain this issue is that it does not occur everyday. At times (about half) I do not have first gear or overdrive. After starting the vehicle and put it in Drive it will be in 3rd gear. I can manually shift to second (with a clank), but can not shift to first. If I do, it stays in second. Also, at times the check engine light comes on, but not everytime. Other times the vehicle runs smoothly with no troubles. I will have every gear in Drive.
Of course when I took it to the dealership, they could not get it to act up. The truck ran smoothly. I even allowed the technician to drive it home for the night. They did state that they tested for a short, inspected the related connection and it could possibly be due to battery voltage being pulled low on circuit 642. They performed road tests several times and are unable to verify at this time.
Any ideas on what needs to be fixed or replaced?