Something is wrong with no warning lights, please help

papertowel

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Buick Ownership
2013 regal turbo premium 3
I currently have a 2013 regal turbo and for a while now i have had a tune on it (about a year) but recently the car feels noticeably slower and I cant figure out where the power loss is coming from or what is wrong. I am suspicious it may have something to do with the transmission but I am unsure. If anyone has some insight i can provide information but I am completely at a loss currently
 
I assume you have not got any trans codes, or pending engine codes? The turbo may be failing but you need to look @ a capable scanner to see what the problem is. All we can do here is speculate.
 
I assume you have not got any trans codes, or pending engine codes? The turbo may be failing but you need to look @ a capable scanner to see what the problem is. All we can do here is speculate.
Yes, zero codes at all and I have a code reader that I would assume is capable.
 
Im suspicious that its something with the torque converter or the trans. The first thing I did was reload my tune and I couldn't really tell if ut changed anything. I also reset the electronics in the car by disconnecting the battery for a while. But ive hooked up my scanner which can read and record live data several times and everything with the engine itself appears to be running correctly. Both 02 sensors look good, the maf appears to be reading what it should be, the fuel pump and HPFP all seem to keep up (though i have gotten codes in the past), it doesnt appear to be pulling timing but I dont really know how much timing there should be at say full throttle. The spark plugs look good and they where replaced not that long ago and the turbo seems to be making the correct amount of boost as well. Recently I changed my transmission fluid because the car began shifting like crap over the summer and it was definitely in need of being changed. it was very brown and or black but there was no chunks or Debris in there. The car since then has atleast been shifting quicker and a little smoother but I have noticed that it still feels like theres not a solid connection between the engine and the wheels thats the best way I can describe it. It still shifts rough sometimes and its delayed when I give it gas, and in auto mode you can see that when you give X amount of throttle the rpm goes up a few hundred like 2 or 3 past what it normally would and then comes back down and rests and almost feels like it kind of locks. There doesnt appear yo be any rpm flair when I shift though it drops right into next gear usally unless I am missing something
 
yes your reader should catch some sort of LOP code, I would start by checking the battery voltage/connections reload your Tune (ZZP HP?) and see if that wakes up your Regal
What connections would you say i should check?
 
Maybe the Variable Valve-Timing solenoids?
 
I was gonna suggest the VVT solenoids as well. When mine started to go out, it didn't throw a code the day it happened. It took a couple of days. If they are going out, it won't shift gears when it's supposed to - on top of that, it won't let you shift it manually (that's how it was for me).
 
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ok sounds like you have a handle on the diagnostics of your Regal, If the transmission was serviced by a Buick dealer you should be ok but I would check the fluid level for over/under fill condition issues. Did you check the fuel pressure with a gauge or scanner? If you're getting low fuel pressure you might have a clogged fuel filter and unfortunately the filter in 2013 is incorporated in the fuel pump. Did you run your diagnostic with the original GM software installed?
 
The car does let me shift manually and symptoms actually improve marginally when I do, I did the diagnostics with a scanner but after doing more research I dont think the scanner can pick up everything. By the original gm software do you mean the stock tune? I did the diagnostics with the tune on but I could try with it un installed. I am currently waiting to use a friend's lift to check the fluid levels and do the rest of the fluid change to make sure most of the old fluid is out. At this point i am even more stumped because the more I dig into this the more it seems it might be more the engine side then transmission. The only clues I currently have to go on are a few codes I found using a different scanner that can do more then just engine codes. I got a u0121 - 00 code for lost communication with electronic brake control module and then a u0432 - 7f for invalid data received from multi axis acceleration sensor module - bus signals erratic. I have gotten similar codes in the past during a hard pull where the car went into limp mode and gave me codes for the fuel pressure regulator and it being to low as well as several other codes relating to communication with other control modules but that was when I was running more ethanol and during a hard long pull. I dont think i can check the variable valve timing solenoid with the scanner unless you mean physically. With looking at all the info from the diagnostics tool im not 100% certain everything looks correct but it doesnt seem very off either, one drive something will look like its off, maybe the lpfp psi is kind of low or during a pull the engine cuts a bunch of timing but then the next drive it seems normal again. And all this while feeling the same, slow throttle response, loss of over all power, the car just feels weird and the gas milage is literally all over the place, within the span of like 2 days i went from getting all the way down to 11 mpg up to 28 for a brief while which js the highest i have seen in a long time, and then back down to 13. I am skeptical it could possibly be the fuel system ie the filter or the regulator ect but I honestly dont know what the next step would be from here. Thank you to anyone responding to this the help is very appreciated
 
Remove the VVT solenoids and check the screen for debris or gunk.
Or just go ahead and replace them. OEM would be best.
 
Remove the VVT solenoids and check the screen for debris or gunk.
Or just go ahead and replace them. OEM would be best.
I will check this either today or tomorrow and see what I find, thank you
 
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I checked the vvt solenoids and there was no degrees or anything on them, they looked fine
 
I could check live diagnostics but honestly I dont know where a lot of these should be sitting at and what would be higher or lower, i can kind of get an idea based on Google ect. But I dont really know like for example how much psi my lpfp should be at ect. So maybe I am missing something
 
Just got some more codes, p2227, p2228 and p0113
 
The sites I checked at point towards the issue being a faulty mass air flow sensor (MAF). Now, they also suggested to check for a dirty or clogged air filter beforehand, as well as things like messed up wiring.

Check the air filter first. If it's good, then I'd replace the MAF with an OEM replacement. Don't play it cheap with some knock off part.


That's what I could find. It's a good thing the computer finally spit out those codes, it really helps narrow down what the issue might be.
 
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I replaced the maf sensor and i havent had the code pop back up (yet) but im still experiencing the same symptoms. I also checked the air filter and its good. Does anyone also know where to start when trying ti deal with the u0121 code that pops up every time I drive with zero lights on the dash?
 
I'm not sure where to go from here, unfortunately. I'm at a loss.

As for the code, I read that it can be caused by a bad ground connection - a classic GM "quirk". I'm not sure which grounds are tied into the ABS module, but they could be loose and/or rusty.....hopefully this can help you out a bit more.
 
After checking over some of the ground points I cleaned one up a hut and then I replaced the connector for the small thin cable going off the negative battery terminal to what appears to be under the dash (can anyone confirm if this goes to the bcm or something else?) And I have noticed that things like the magnetic ride control seems to work better now Along with steering feeling better and the car being over all more stable, I think im still having some other minor issues but the car still runs much better then before after doing this and the maf sensor. Whats weird though is after I did that it spit out a bunch of new bcm codes when I scanned it 2 days later

B1529-03 FAIL SINCE CLEAR| HISTORY Control Module Voltage Reference Output LO Circuit - Low Voltage

B3867-04 FAIL SINCE CLEAR| HISTORY Right Park Lamp Control Circuit - System Internal Malfunction

B3867-01 FAIL SINCE CLEAR| HISTORY Right Park Lamp Control Circuit - Short To Battery

B1517-5A FAIL SINCE CLEAR | HISTORY Battery Voltage - Not Plausible

B270A-01 FAIL SINCE CLEAR| HISTORY Park Lock Solenoid Actuator Control Circuit - Short To Battery

C0890-03 FAIL SINCE CLEARI HISTORY Control Module Voltage Reference Output 3 Circuit - Low Voltage

I dont know if these would have maybe just popped when replacing it or if something is wrong? The only problem i have now really with the car is it feels like half the time its stumbling under load or boost, like boost comes but it wont pull like it did before still, and im still getting like 10 - 15 positive ltft sometimes dipping but I cant find a pattern, along with the 02 sensor hanging around .8 .9 and then spiking down and back up rather then like a nice clean oscillation.
 
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