No 1st or 2nd Gear - Third Gear Start - keywords 4T80E high launch low MH1 power shift slip

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Vehicle may exhibit third gear start, no first or second gear and/or first and second gear with no third gear.

Delamination of the lower valve body 2-3 shift valve bore, which may require replacement of the valve.

Dealer will need to replace the lower valve body.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.