Brand new Sierra - Codes P25A2 - U0101/100/146

DutchTexan · May 12, 2020

On 5/10/2020 at 11:22 PM, Rocky Mountain At4 said:

A quick update. GM engineers told me my truck was safe to drive with the aforementioned codes and said they are working on a fix. That did not make me happy, but whatever. Then today, the check engine light came on again and my transmission started going downhill fast. It started making hard, jerky shifts before it decided to shift into I would guess 3rd gear while I was doing 75 mph on the freeway. The rpms went to about 4500 instantly. I got off the freeway a d it did not shift out of that gear for the rest of the trip. After shutting it off and driving it again about 3 hours later it was shifting with major issues. At one point it would not advance gears and was just revving/bouncing off of one gear almost like I was hitting the rev limiter even though it was at about 3000 rpms. OnStar is showing codes P0700 and P2715 with the following description.

The Engine and Transmission System is not performing as expected. An issue has been detected in the Transmission System that transfers power from the engine to the drive wheels. You may experience reduced power or shifting issues.If the vehicle is continually driven with the check engine light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, and the engine might not run as smoothly. This could lead to future repairs.

This truck is not drivable or safe. I will be going back to the dealership for the third time. I have just over 1200 miles on it now...

We’ll this is a real kick in the nuts. I’m in the middle of a night shift trying to figure out what’s wrong with my brand new truck. It sounds a lot like what you started off with...

2020 GMC 1500 Denali with 263 miles on it. I’ve had it for 3 weeks and the check engine light has came in twice now. First time I thought it was a fluke, because it cleared quickly, but now it’s in again.

I can’t feel anything wrong with the truck. There is a weird clicking noise on start up idle that I don’t remember earlier, almost like the belts are wet or something.

The other thing is radio glitches. Sometimes when I remote start it and get in quickly, or I get in and start it up with the button inside the screen glitches on and off and the radio cuts in and out for about 20 seconds. Really irritating.

I’m going to try and get some codes read in the morning and maybe stop by the dealer between shifts. Will keep you updated..

Any one else have the same issues? I looked up my VIN and there are no recalls or updates apparently. It was manufactured 03/20 in Mexico.

bigfelipe · June 4, 2020

78 miles on my new Silverado LT I picked up 2 days ago after leaving it over the weekend for a recall repair upon purchase... I have the same 4 codes per OnStar, 3 ABS, 1 ECM...

I really hope I didn't buy a lemon for my first new truck purchase in 20 years...

HuffDad70 · June 10, 2020

Following this. Had the same codes pop up on my truck, 2200 miles on it. My wife mentioned that last week when she drove it the brakes seemed to give out once and that all traction control was lost for a brief minute. It was raining fairly hard that day and we just chalked it up to slick pavement as no error codes got thrown at the time. Maybe it was a prelude to this. Heading to the shop on Friday to get it looked at, but hearing what is in here and the other thread doesn't have me feeling hopeful.

OnStar did note that the battery may drain, which i see other mentioning. I did monitor the amps as I was driving (safely) and noticed that they jumped anywhere between 9 amps and 14 amps, mainly siting around 12.5 amps though. We cranked the A/C all the way up, had the radio on, turned on headlights/bedlights/fog lights/towing lights and didn't notice a huge draw. Maybe a 0.25-0.5 amp drop with it all running. The drop to 9 amps was random and was when I was idling at a stop light with nothing else running.

bamorris2 · June 10, 2020

Based on my personal experience and several other posts that I’ve seen, these trucks are just super sensitive to battery drain. The exact same thing happened to me a few months back when I listened to the radio with the engine off for about 45 minutes. I got the same group of 4 (I think) codes. A few drive cycles later they disappeared.

For the poster above, this would also make sense for a brand new truck that sat in the lot. Also applicable when the service techs perform the recall. The procedure specifically states that they need to keep the battery on a charger for the duration of the calibration upgrade. I’d bet that many don’t though.

HuffDad70 · June 15, 2020

Follow Up:

got my truck back today. Dealer found the error codes P25A2, U0140, U0131, U0151, and U0146. They said that bulletin #PIT5735B was found, matched the codes, and as previously stated here its the brake module sensing movement after the truck is turned off. They adjusted calibration of BSCM to compensate, but engineering is still looking into it. My driveway is on a slope, so just make sure that I apply the parking brake prior to taking my foot off the brake, and do all this before turning the truck off.

TMT54 · June 17, 2020

I have a 2020 1500 Denali and after being stuck at the dealership for a month ( another long sad story), The CEL came on one day after I got it home. The error was P25A2. I took it back to the dealer and since they couldn’t look at it and the truck wasn’t doing anything wrong, I just had them clear it. We thought since the truck had been sitting for a month, maybe it was just a fluke. No problems for the next three weeks and the CEL came on again. This time it was P2B60. Basically the same message, but the first one complains about temperature and the second one complains about voltage. The service manager said there is a service bulletin that address both of these codes and recommends replacing a sensor. Again the truck was running fine and the next day the CEL was not on. They ordered the sensor and I’ll have to get the bulletin number from the dealer, but I’ll post the bulletin, part number and if it actually fixes it when I know more.

smreese · June 20, 2020

I have a 2020 GMC Sierra 1500 with 3400 miles and having the same P25A2 problems. Took to dealer, they applied PIT5735B bulletin recalibration fix. Lights all came back on next day, ABS, traction control, stabilitrac and engine light. Back to dealer. Now they want to replace a sensor and they say it is on back order. This is ridiculous. Going to lemon law it if it does not resolve with sensor replacement.

2017Z · June 21, 2020

Anyone posting here recent have any successful fixes? New 2020 Trailboss 6.2 and having all these same errors, codes, battery draining , auto setting parking brake for no reason, and CEL random. First set of codes was 2 days after I bought the truck. Apparently reflashed computed and recall update applied even though when I drove it off lot all recalls were cleared. 3 weeks later truck was dead and battery drained and took a whole day to charge up and the dash was flashing every code under the sun and said don’t drive truck. Chevy found no issues. Now getting ready to take a road trip and CEL light comes on after the truck sat all night and we packed up and started. Will go back again to dealer tomorrow. Ridiculous. Brand new truck and seems unreliable. Also forgot to add that fuse 82”TIM” blown for no reason and affected my running lights on my trailer.

Edited June 21, 2020 by 2017Z

HuffDad70 · June 21, 2020

2 hours ago, 2017Z said:

Anyone posting here recent have any successful fixes? New 2020 Trailboss 6.2 and having all these same errors, codes, battery draining , auto setting parking brake for no reason, and CEL random. First set of codes was 2 days after I bought the truck. Apparently reflashed computed and recall update applied even though when I drove it off lot all recalls were cleared. 3 weeks later truck was dead and battery drained and took a whole day to charge up and the dash was flashing every code under the sun and said don’t drive truck. Chevy found no issues. Now getting ready to take a road trip and CEL light comes on after the truck sat all night and we packed up and started. Will go back again to dealer tomorrow. Ridiculous. Brand new truck and seems unreliable. Also forgot to add that fuse 82”TIM” blown for no reason and affected my running lights on my trailer.

So far the fix to mine has not resulted in any more error codes or the CEL coming on. Though I am following their recommendation when parking anywhere that looks like its remotely sloped. I have been putting it in park, taking foot of brake, letting it come to a stop, and giving it a second before turning it off so it realizes its not moving. I haven't actually TRIED not following the guideline, mainly as I don't want the CEL coming back on and having that pop up. But I am keeping an eye on it and following this thread, so will update if anything changes.

2017Z · June 21, 2020

Crazy that’s the work around. Truck was parked in my flat garage so not sure why it did it. Bought a code scanner and Looks like it’s all the same as what everyone is talking about which really equates to a software blunder on GM part. See what service says tomorrow.

TweetybyrdRT · June 23, 2020

I got the check engine light and the same codes on Saturday, it was off by Monday when I drove the truck to work. Had an appointment at the dealer for this afternoon but decided to cancel after reading this thread (will also be changing dealer due to customer service issues).

I don't have any of the battery drainage issues and the gauges are all good, so Ill try the brake trick and see if the light stays off and wait until there is a fix for the actual issue. I'm in the 3.0 so this obviously isn't a power train specific issue.

TMT54 · June 29, 2020

I haven’t had any new issues since the CEL went out on it’s own, but I’m still waiting on the sensor that the dealer claims will fix the problem. It’s pretty frustrating to wit a month for one part and two weeks so far for the next part. I will say that even though the EL came on, I didn’t have any problems with the truck, which make me think it’s a sensor or software issue.

jbr1888 · July 6, 2020

2019 Sierra SLT Crew Cab 1500 X31 6.2L with 13k miles. The truck has frequently made noises after I turn it off and inexplicably applied the parking brake. The noises sound like relays or servos clicking and humming. They're pretty loud. Then today I got in it drive home from work, and saw the CEL. I used my OBD2 device to read the codes and got Codes P25A2 - U0101/100/146.

Sector7500 · July 8, 2020

Add another 2020 Sierra with 700 miles to the list of trucks with this problem. Calling the dealer for an appointment but it sounds like this will take repeat repair attempts.

Started truck up this morning with check engine light on.

Called OnStar and received the following Codes:

P25A2

U0100

U0146

whitesierraRT · July 10, 2020

I've had this 25A2 error off and on since I bought the truck in Feb. After one dead battery and several trips to the dealer I thought it was working ok. Not the case. The CEL didn't come back but code could not be deleted. When I took it in to have the shop delete the code, which they did, they said it had another recall concerning DEF. This time it had something to do with the DEF monitoring. My DEF gauge read one square down but after their fix it read 3/4 full (1500 miles). A few days later it read full again. I sent the service agent an email asking what to do next. No response so far. I will probably have to call or drop in for a response. BTW I never received an official DEF recall notice. No CEL at this time.