My check engine light keeps coming on and the code is P0236 which the code reader says is Turbo/Superboost Sensor A CKT Range/Perf. Does anyone know what this is or what I need to do to fix it?

Thanks

Go to the main page and look for a post on RPO codes,, and then Fill out a Sig for you truck so we know what you got to help you better. Read the FAQ sections,, and use the Search Button!! Also Welcome the The D/P. Don't want to sound like a helpless prick or anything, but I thought I'd be the first to tell you this before about 10 others do!


http://www.dieselplace.com/forum/showthread.php?t=42248

OK I will try to figure that out. Went through the turbo troubleshoot guide and looks like I have a wastegate solenoid problem. At idle the flapper actuator was not closed but I could close it with the linkage. I haven't noticed any smoke or other things that were symptoms, hope the solenoid is the problem, the CE light is getting annoying!!

Thanks

Check for vacuum from the WG actuator back to the electric solenoid on the drivers side.

The actuator can go bad. If you apply a small amount of vacuum to it with a vacuum pump (or your lips), it should hold that vacuum. If that's bad, then hold on to yer wallet; it is almost $400. You'll probably want to fix it with a Turbomaster.

Troubleshooting the system is easy once you understand how it works. Read up and go forth and solve your problem.

I tried that yesterday, it did close. Where can I find info on the turbomaster?

I tried that yesterday, it did close. Where can I find info on the turbomaster?
Here: http://www.heathdiesel.com/T/Chevy-GM/

Thanks!!

Alot of us make our own out of the factory wastegate actuator, it is easy and cheap if you can weld and have a welder or access to one. You only need one or two small welds. Do a search for it.

I had some time this weekend and checked the vacuum pump which pulled a good vacuum. Downstream of the solenoid there wasn't much of a vacuum at all, barely showed up on the vacuum gauge. I connected a water tube manometer and got about 9"WC and I could see the vacuum pulse like it is supposed to do. The wastegate actuator works great when a vacuum is applied but the vacuum it is getting from the solenoid is barely enough to crack it open at idle.

Bad solenoid? And I assume this is the reason I keep getting P0236?

Thanks.

Yep... bad solenoid. The ball that moves around in the solenoid oxidizes, then doesn't seal or move properly, and then you get what you've got. You can try some WD40 to see if it helps at all, but... even if it does help, it may only be on borrowed time.

Thought I would check it again before ordering the solenoid. I bought some tubing and jumped the two vacuum connections at the solenoid, the wastegate actuator didn't move hardly at all. I then got a vacuum gauge off my AC manifold and it would barely move the needle, maybe 1"hg. What else does the vacuum pump run and is there any good way to check it? I checked the line from the pump to the solenoid and it was good. I might just order a new pump as it didn't look that easy to replace it. Any other ideas?

I might just order a new pump as it didn't look that easy to replace it. Any other ideas?

From one of your earlier posts I thought the vacuum pump was good...?
Are you sure the hose from the solenoid to the actuator isn't split?

if your truck is a "F" engine(most likely is being a 3500 dually) the the vac runs just the wastegate. if the vac pump is dead i'd say remove it and get a shorter belt.

a replacement vac pump isn't cheap, mine was over $100. a heath turbomaster(get a boost gauge if you don't have one) is about the same price and does a much better job at giving sustained boost over the factory boost jumping up and down. you can check out Heath's products here (http://www.heathdiesel.com/T/Chevy-GM/Chevy-9601/) you can build your own turbomaster for around $10 if your handy around the shop as well.

Yep I messed up, I didn't notice that it said In.Hg. which is a lot different from In.WC., it barely pulled 9"W.C., I don't know if it is an F or not, will have to check, if it is I will do exactly that, get rid of it.

Yep I messed up, I didn't notice that it said In.Hg. which is a lot different from In.WC., it barely pulled 9"W.C., I don't know if it is an F or not, will have to check, if it is I will do exactly that, get rid of it.


i'm betting its an "F". check the 8th digit of your Vin number. the 6.5 turbo's are either "F" for the HO engine(2500HDs, 3500, 3500HD) or "S" for the EGR engine(1500s, 2500LDs)

Yep it is the F engine. I wonder why they put that huge vacuum pump on there when they could have used a small 12vdc pump.

New vac pump is more like $200, and the piece of sh*t isnt worth shit IMO :D I bought mine with a dead vac pump, cut open the stock WG controller, added some all thread, a stiff spring, a washer, and two nuts and made my own turbomaster. My highway mileage i think has dropped a bit with it verses the stock system but its worth it to have power. I think new injectors and a good exhaust will take care of the mileage thing tho.

There were a couple on ebay for buy it now of $129 but I am not going that way if all it's used for is the wastegate. So you used a really stiff spring?

One last question, if I remove the vacuum pump will I get the same P0236 code showing up all the time? And does anyone know exactly what triggers this code?

Bad solenoid? And I assume this is the reason I keep getting P0236?

Yes. Cheap and easy to replace.

I guess my question is there is really no feedback on either the solenoid or wastegate correct? The MAP sensor must be the cause for the code whether it is sensing low or high pressure.