Auto-tranmission won't shift

[Solomon Ngan <sngan@netaccess.on.ca>]

Hi everyone,
A friend of mine just got his car back from an auto-body shop for a
front-end body repair.  The repair is "body" work and painting only. 
The problem is his automatic transmission won't shift up to higher gear,
ie: his physical lever position is "D" but the engine is revving @ 5K in
city.  His car is a '93 100.
Could it be the ecu that controls the auto trans ?
Is there a fuse that protects this circuit ?
Could it be the transmission itself ?
His car is only 70,000 Km.  It was driving great before the repair.
Obviously whatever happens happened during the repair, or painting, or
curing of the paint ?
Can someone help ?

Solomon