i'm getting an occasional SES light running about 2100 RMP's or 70 MPH and above, some days it comes on then go off a few time while other day it doesn't. i'v noticed it more when pulling a trailer (1,500 lbs or less) or running the A/C:confused:. I don't have a scan tool yet or access to one working on that now. I have checked the vacuum 24-25" before the wastegate solenoid valve and 15-16" at the wastegate, and the vacuum lines all at a idle. no gauges of any kind yet agian working on that too. what kind of scan tool are ya'll using? i need to get one but i'm on a budget. Thanks

is it intermittent or does the hard code light set and stay, if it stays many part stores autozone/advance etc. can/will read hard codes for free.

In a 94 do you need a scanner to read codes? Won't the old paperclip method work?

Yes you are correct I missed that I'm on a conference call and reading and listening at same time, in FAQs paperclip read procedure is there.

Gotta love it when you can use a paperclip instead of spending the big bucks....

Here is the link to the instructions:
http://dieselplace.com/forum/showthread.php?t=16399

I didn't try the paper clip, not for sure how i'll read the FAQ's for it. the light stay on for about 3 or 4 seconds then off. All the parts stores here say they can't read the codes for diesels. thanks for all of the hep this place is great!!!!!

I can scan that truck and trouble shoot it too. Paper clip method is roadside friendly for anytime DTC retreival and removal of soft codes. Just jump the top right pin to the one left of it( A to b) on the aldl connector below the dash. when the terminals are jumped the codes will flash out. write the numbers down and then step on the fuel pedal and hold it down 'till it only flashes 12.

Let me refer you to my referal.http://dieselplace.com/forum/showthread.php?t=31999

Thanks every one for the help. I'm going to try the paper clip while at lunch today and report back with what i find. Quantum thanks i'm going to lease this weekend, maybe once i get back if you have time we can get together and you can learn me some things ):h. I'm guessing your some where around Houston?

Here's what i got. code 29, 35, 36, 38, 41, 74, and 78. code 29 i get because the glow light comes on after the truck is running guessing thats related. codes 35 and 36 worry me since i just put a new IP on it about 2,000 miles ago. I made sure that the timing dot's were lined up when put the new pump on, but i did rotate the end of the pump so the pin would line up in the gear. do codes 38 and 41 have something to do with the brake switch on the brake pedal? reason i asked is i just put a new on about 10,000 mile ago. code 74 and 78 don't know. I reset the codes, and will check them again after i drive it home to see which ones come back. By the way the truck run goods no hard starting or smoke (a little puff of white smoke when first started) didn't think there would be that many codes.

DTC 78 - Turbo Wastegate Solenoid Fault

I think this one is missing from the list I linked to

mtrenegade, yes it was missing thanks for filling that in for me. I have a filling that's the one thing i need to change. i replaced the vacuum pump about 22,000 ago but not the solenoid.

Get a turbo master and a chip and 90% of your problems will go away forever. OH and your truck will haul a$$ too!

MDT you know that and i know that but my wife don't see that way but i'm slowly get her around to it;) . checked the code after i reset PCM once i got home and only had a 78. got the new one coming and should be here before i leave to go to the hunt'n lease. Huge Thank to EVERYONE that that helped:ro) !!!!!!!!!!
BTW this is the 1st forum i've posted on, I'll be back.