94 k2500 not shifting

[Dan C]

Went to use my truck yesterday but it wont shift out of second. It was working fine when parked the day before. 94 6.5t k2500 any ideas? Thanks DanC:confused:

[JohnC]

Check for DTC codes. If you get 81, 82 or 83 then check the power on the trans circuit, especially when powering up the truck. If it drops while the PCM is trying to test or actuate the solenoids in the trans the trans will default to 2nd gear (all solenoids off). The ignition switch is a common cause.

Also, if you notice issues with the tach or speedo, points to the same thing.