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Discussion Starter #1
On my way to a Dr.'s appointment earlier today, on the highway, my 2013 ATS 2.0T manual with exactly 93,000 miles slows down. I then get a CEL, no TC, no SC, and Stabilitrak warning. I pull over, plug in my bluetooth scanner, and get code P288C. I look it up and it's a Fuel Pressure Regulator Sensor, low pressure code. I semi-limp it to the Dr. and start researching while I'm waiting. I come across TSB 18NA072 which describes exactly what I'm experiencing with the car. I knew I had some sort of warranty left on the car from what I saw on the my.caddillac.com site (Special Coverage 15824), so I figured I'd call up the dealer and see if there was any chance something like this could possibly still be covered. They pretty much said it might be, but they need to pull the code themselves and inspect the fuel system themselves and that if it matches the TSB it should be covered.

Well, I get back to my office and start digging a bit more. Everything I can find on that TSB only applies to the 3.6 LFX with E85! I also look up my warranty and it's specifically for faulty camshaft actuators, nothing to do with the fuel system. Are they just blowing smoke to get me to bring my ATS there and charge me for the repair, or am I just missing something. They can't even accept my car their until a week and a half from now, so I have some time to cancel the appointment. If there's no chance of this being covered, I'll bring to a local guy rather than the 30+ mile away dealership.

Just a few more details. As long as I slowly bring it up to speed and don't lug it, it feels absolutely normal. If I get the needle moving too fast, it feels like I just took my foot completely off the accelerator for a bit. It doesn't get rough or start bucking, it just loses quite a bit of power. I didn't smell or see any gas under the hood, but I'm going to give it a closer look when I get home today. Looks like I'll be driving my punishment car for a bit (a 2007 Toyota Corolla CE that we kept after my wife bought a new car so I still have something to drive if/when I screw up my ATS).

Thank you for any insight or guidance you my have for me!
 

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Yeah that TSB is for the 3.6, I think the stealership is trying to reel you in:


Kind of weird when searching for P288C (I presume you didn't typo), you get a lot of hits for P228C, which is the code referenced in that TSB. But just restricting results to 288C, some are for fuel rail pressure, some are for MAP sensor/oil temp sensor or O2 sensors???


Confusing to say the least. But if it is related to fuel/air mixture, can't hurt to check for a vacuum leak. Kind of interesting that the 2nd and 3rd links refer to oil temp sensor or oil pressure solenoid.

And I'd take it to a good independent shop vs that dealership if you can't figure it out.
 

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228C indicates the fuel rail pressure isn't reaching commanded level and that fits with the loss of power under heavy engine load. This typically occurs when the cam driven high pressure pump is worn but it can be caused by a feed side restriction or leakage on the high pressure side (i.e. injector that is stuck open).

The GM TSB was for a known condition with a pump used in a few different engines but the 3.6 was the only one of these offered in the ATS.

If you are going to troubleshoot this yourself, you will need the GM manual for your car so that you have the procedure and data for checking flow and pressure on the feed side (low pressure fuel pump from the tank) and to also check "leak down" on the high pressure side before replacing the somewhat pricey high pressure pump. If the high pressure pump appears to need replacement, also check the cam lobe that drives it for wear to ensure it is the pump itself that is the issue.

Be VERY careful when trying to home service this system. The high pressure side of the system pressurizes the fuel rail up to a few thousand PSI and this can inject fuel directly through your skin in addition to creating a fire issue from a fuel spray. The high pressure fuel system in a GDI engine has a lot in common with a diesel engine or hydraulic system where you are dealing with a very highly pressurized liquid. I remember when I bought my Deere compact utility tractor several decades ago that the owners and service manuals included warnings along with a 24 hour number for your doctor to call in Moline if you injected hydraulic fluid into your skin while trying to check for leaks the wrong way. Rapid treatment was needed to avoid gangrene which sounds like a very good thing to avoid!

On Edit: There is a VERY slight possibility that this is caused by a buildup on the pump strainer in the tank so you could try a dose of Techron if you haven't been using Top Tier fuel (Techron or its equivalent is pretty much what makes Top Tier fuel special, it isn't otherwise some high quality fuel variant). I seriously doubt that this will help because it is rarely the cause but it is a cheap experiment. But the odds of this curing the problem are extremely low.

Rodger
 

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Discussion Starter #4
Canceled my dealership appointment and am taking it to a local shop near my house that does very good work. I'm a little bummed they would jump to mislead me like that. They've been a really good dealership to me for all the years I've had my ATS (though, I can't really say I've been the best customer. I've, personally, never given them a dime of my money. Everything they've done on my car has been either the free maintenance or warranty repairs. Nothing extra).

I tend to overestimate my mechanical abilities, pretty much every time across the board, but the high-pressure fuel system is something I KNOW I shouldn't be touching regardless of my (over)confidence level. That is some scary stuff, for sure! Though, I have a suspicion that something is leaking somewhere and it wouldn't be pressurized. I found that if it's been driven recently, it fires right up, but if it's been sitting for a while, like a couple of hours, it has to crank for a while to get going. I don't see any fuel anywhere, though, nor do I smell gas at all. Stuck injector, maybe?
 

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I found that if it's been driven recently, it fires right up, but if it's been sitting for a while, like a couple of hours, it has to crank for a while to get going.
That is a symptom of fuel pressure bleeding off.

I had that happen on a 98 Z28. When I put a pressure gage on the test port, pressure would be normal while running. But when shut off, pressure would slowly bleed down. After a couple of hours, it would be zero. So when I would try to start, it would crank until pressure was high enough for the injectors to do their thing. Suspected in tank pressure regulator, but it ended up being a pinhole leak in a hose in tank.

Stuck injector would cause it to run rough, but you say it feels normal at light throttle? If an injector is leaking bad, you will smell gas in the oil.
 

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Taking it to an independent shop makes sense for an out of warranty vehicle. High pressure common rail systems for gas engines has been around for well over a decade now so independent shops are well versed in the system and have the necessary tools for checking.

Angel71rs makes a good point which is the reason why the first check the shop needs to make is on the supply side to see whether proper fuel pressure is being maintained on the low pressure side when the engine is under load. A failing low pressure pump or problem with the pickup or in tank connections will create low supply side pressure preventing the high pressure side from developing proper rail pressure. All the code is telling you is that the high pressure side isn't able to reach commanded pressure under load but it doesn't show exactly what is causing it so tearing into the high pressure pump and common rail is the expensive side that should NOT be the first step.

Although I would expect for there to be additional codes, an issue with the control system to the high pressure pump can also cause this problem. The high pressure pump has to be able to develop a wide range of volume/pressure over a large RPM range and a control system provides both coarse and fine steering of this delivery pressure with the rail pressure sensor providing feedback to the ECM. My 2008 CTS had the first GDI engine I owned and when it was a couple of years old, a flaw developed in the control harness to the high pressure pump. I can't remember now what codes it threw because it was under warranty but when a flatbed arrived for its trip to the dealer it barely developed enough power to pull itself onto a very gently inclined flatbed.

Until you get it into the shop, avoid putting a heavy load on the engine. The ECM will try to keep the AFR in proper trim but with the inability to maintain proper rail pressure during a transition the AFR will at least briefly go very lean resulting in extremely high combustion temperature which your valves, piston crowns, and turbo won't like very much.

Rodger
 

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As Rodger stated above, be very careful around high-pressure fuel and hydraulic lines. Now that high-pressure fuel lines are commonplace in everyday vehicles, the general owner/home mechanic should be aware of such hazards, as they are no longer only associated to highly specialized equipment.

As an engineer in the aerospace industry, we have to be mindful of this while around aircraft, flight testing, etc. I would rather not post a link to such a serious video (dramatization), but this will really bring attention to the seriousness of an oil-injection wound!


Anthony
 

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I would rather not post a link to such a serious video (dramatization), but this will really bring attention to the seriousness of an oil-injection wound!
Interesting video, nothing like visuals to bring things to life. I know The Man from LOX safety film we had to watch in the military is still seared in my memory! ...suggest not googling that one, you don't want to see the uncut version because what has been seen cannot be unseen.
 

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Thanks for posting that Yank05, it should bring safety home to people.

My other strong memory from my tractor purchase is the very graphic decals on the power take off shafts for the implements with a person being pulled apart by the PTO shaft. One of the local farmers lost a foot from getting tangled up in a PTO shaft.

Rodger
 

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Thanks for posting that Yank05, it should bring safety home to people.

My other strong memory from my tractor purchase is the very graphic decals on the power take off shafts for the implements with a person being pulled apart by the PTO shaft. One of the local farmers lost a foot from getting tangled up in a PTO shaft.

Rodger
You're very welcome - I have been passing it along to educate others since I first viewed it some years ago.

Anthony
 

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Discussion Starter #12
Well, that's a shame. Local shop got a chance to look at my car early. He plugged it in, but the car isn't giving him enough information to troubleshoot and determine exactly where the issue is. They recommend I bring it to a dealer. :mad:
 

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Sounds like the local isn't willing to deal with a moderately complex issue. If you have another independent, then give another shop a try.

DTCs are data to guide the repair person in making a diagnosis and repair but often they do NOT tell you exactly what to do so the process still depends upon a tech applying experience, knowledge, and logic to the problem. Another version of the same lecture I used to give my international marketing grad students about market research, it provides guidance to an intelligent decision maker but it does NOT make the decision in and of itself and still requires that the manager process other input in order to make a good decision...

Rodger
 

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but the car isn't giving him enough information to troubleshoot and determine exactly where the issue is.
You were giving him enough information for an entry point to start troubleshooting if you told him about delay in starting when parked for a while. He should have at least hooked up to pressure test port and checked for pressure bleed off.

Wonder if these cars have pressure sensors for the low and high pressure systems? If so, monitoring them would show if low or high side pressures were bleeding off and help isolate which system to troubleshoot.

edit: looks like direct injection systems have gone to pressure sensors for both high and low side pressures:


GMs still have a test port for low side:


Seems GM uses PWM for the electric pump, so they use a pressure sensor on the low side, so fuel system controller regulates pressure instead of a mechanical regulator used in the past:

 

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DTCs are data to guide the repair person in making a diagnosis and repair but often they do NOT tell you exactly what to do so the process still depends upon a tech applying experience, knowledge, and logic to the problem
Having spent 32 years as a dealership parts manager, I wish I had a dollar for every customer that came in wanting "The part to fix a code (insert DTC here)". I could have retired on a tropical island.

I'd explain that the code only told a tech which section of a 20lb manual to begin troubleshooting a problem.

Some would still argue - "Naw, you just put that code in your computer"...........

Uh, OK.
 

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Rudy,

I bet that you really miss those days :)

If it was your last day on the job, you could sell them that special order part that was never picked up along with instructing them to stop by NAPA on the way home to get the required left handed monkey wrench to install it. If you were feeling particularly evil you might also tell them you noticed some noise from the exhaust system and that it would be a good idea to pick up both the front and rear muffler bearing sets before they failed on the road and that NAPA should also have those in stock.

As a colleague and I were discussing earlier this week, we could have had so much fun with our job if we hadn't actually needed the job :)

Rodger
 
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Discussion Starter #17
Just to close this out, dealer figured out it was the high-pressure fuel pump and now it's back to normal.
 
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