I believe it is designed to do that as a part of it's "limp home" mode.

I'd suggest checking the coils to see if any are wet on the side that is not firing.

In your climate it may well resolve itself in a day or two with the hood up.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)