Ok i have too experienced a ses light it happend going up an extreme grade in CO with a 5th wheel. Both times it happend it was at about 15psi full pedal (teatering just where it wouldn't take it out of od). Pyro was still doing fine about 10 and a half. i checked the codes, came up with a 1211 i just replaced fuel filter 5000 ago will do again tomarow and did oil 5000 ago will do again tomarow. Is there anythign else i should check?

 

1211 comes from the HPOP not being able to keep up with the demand.

Oil level and Age OK?

 

Level ok age 5000 miles. I don't think this should cause a poblem.

 

It can be here are all the possibilities

DTC P1209 and P1211 indicates that injection control pressure was above or below desired level under normal driving conditions.
Possible causes:
incorrect oil or viscosity
poor oil quality
gel fuel/no fuel
low fuel pressure
damaged IPR valve
high-pressure oil system leak
damaged high-pressure oil pump
damaged PCM

 

What year is your truck? I get the good ole 1211 code whenever i drive my truck, unless its on stock then i wont pop the code.

 

2000 with 208000 miles.