2013 Cascadia Fault 1 fault 2 eng1 636spn, engine light is on.

Fault 1 fault 2 eng1 636spn can someone tell me what those codes mean . My engine light on . Today my truck was giving me a hard time starting up. I had to crank it 6-7 times then I got a little jumó box and cranked it 2 more times and was able to get it to turn in. My engine light been coming on and off lately so just wanted to see if anybody can help me out. I was getting charged 300 just to plug my truck up and them tell me the codes on the dash

 

2013 freightliner cascadia dd 13

 

No that’s the codes it say on dash . I didn’t get it scan because the price is a lot

 

2013 freightliner cascadia dd13