The code P2138 is "Accelerator Pedal Position (APP) Sensor 1-2 Correlation", which i guess means that the pedal position sensor does not match some other sensor. I think that is the same as just 2138 since there isnt one like that. I've heard of this happening to someone else as well, just required the pedal to be swithced out.
Donno if its an urgent dealer thing, but i would take it as soon as you have free time, might cause stabilitrak or TC or abs to malfunction.
