U0101 / U0129 Codes and CEL

splatmatt · April 16, 2020

I have my truck (2019, new body style, crew cab, WT, ~5.5k miles) now at a different dealership. I figured since several dealerships in my area seem slow that they would spend more time investigating the problem. My codes are like those previously posted by others, but without the P codes. When I scan the modules (Bluedriver scan tool), codes are either pending or in the history. It may take several tries to clear the codes leading me to think there is a connection issue to one or several modules (or a short). I dropped the vehicle off Tuesday morning and last night was informed they were going to spend Thursday going into more diagnostics, vague so far but the service advisor seems to be willing to help (unlike the previous dealership I went to several times).

Edited April 21, 2020 by splatmatt

Brizzo Jenkins · April 16, 2020

18 minutes ago, splatmatt said:

I have my truck (2019, new body style, crew cab, WT, ~5.5k miles) now at a different dealership. I figured since several dealerships in my area seem slow that they would spend more time investigating the problem. My codes are like those previously posted by others, but without the P codes. When I scan the modules (Bluedriver scan tool), codes are either pending or in the history. It may take several tries to clear the codes leading me to think there is a connection issue to one or several modules (or a short). I dropped the vehicle off Tuesday morning and last night was informed they were going to spend Thursday going into more diagnostics, vague so far but the service advisor seems to be willing to help (unlike the previous dealership I went to several times).

A lot of people seem to have this issue after getting the last brake service module recall completed. I got mine completed about a month ago. All was fine until today. I’m thinking the two are connected somehow. Definitely smells like a software issue. But dang, how many more times do we need to get this thing software updated.

splatmatt · April 16, 2020

Quote

A lot of people seem to have this issue after getting the last brake service module recall completed. I got mine completed about a month ago. All was fine until today. I’m thinking the two are connected somehow. Definitely smells like a software issue. But dang, how many more times do we need to get this thing software updated.

I had the same issue prior to the last update in performed in Feb.

splatmatt · April 17, 2020

Some good news: My dealership called moments ago and said that Chevy had new module updates (posting yesterday) regarding this issue and that they are going to apply them today and further test drive on Monday to confirm. I will let you know more when I get the truck back and post any relevant info.

****Update

Dealer said they applied TSB# PIT5735a which I believe is this:

https://static.nhtsa.gov/odi/tsbs/2020/MC-10173676-9999.pdf

No error codes - I will update later this week

So basically the brake module is staying on (after turning vehicle off) and reading the wheel sensor. Dealer said they flashed brake module with new firmware to fix issue. The TSB dated 3/4 mentions that GM will provide an update later to correct issue. From my understanding the dealer just got this new update a few days ago. Time will tell.

So if all of the error codes are listed under the brake module then this is your problem. In my case, the bluedriver scanner shows the truck's error codes were from the brake module.

Edited April 21, 2020 by splatmatt
update

Z71NY · May 4, 2020

Add me to the club. 19 Silverado Z71 Had oil change and brake reprogram recall done last week. Check engine on today with U0100, U0101, U0146 and P25A2. Check engine now off when I shut it off and started it ten min later.

Z71NY · May 6, 2020

UPDATE

My MIL has stayed off since it turned itself off. I’ve never had any actual symptoms of the codes listed. Dealer referenced this TSB for a fix. We’ll see.
https://static.nhtsa.gov/odi/tsbs/2019/MC-10164122-9999.pdf

Brizzo Jenkins · May 7, 2020

I originally had the brake control module software update done 2 months ago. (Brake pad life Remaining percentage was counting down too fast). I got my first check engine light with codes about a week after that. I used my scan tool and cleared the codes.

but then, 2 weeks ago, I get a letter from big (corporate) Chevrolet saying that there is an issue with the brake control module software that needs to be addressed. The letter also stated that, “even if you have already had the software update done in the past, it will need to be re-updated again.“ so I took my truck back to the dealer again, 2 days ago for the second time for this same “update”. Guess the first software update had a bug.

so far so good with no check engine light or engine codes. Idon’t know if the faulty software update and the engine codeissue is related, but so far so good. I’ll keep you all updated

Z71NY · May 7, 2020

I had that second update, and two days later is when it came on.

Elpresidente · May 29, 2020

Gentlemen we have a fix. PIT5735B has corrected the issue. I had the software update for the BSCM/brake module controller applied to my truck on May 27 2020. The PDF does not look like it is published online yet, so it is attached below.

Had a GM engineer apply the BSCM with the mechanic at the dealership. The engineer also mentioned the PIT5730A & PIT5735B are both addressed in the same latest software update.

If you read the description it is caused by the vechicle just rolling a little when parked. Although have never had a auto issue raise so many codes period; especially for a root cause being so minor.

20200529085624982.pdf

Edited May 29, 2020 by Elpresidente

Vickroy · January 6, 2021

Wanted to add in my experience here. Had same CEL and codes thrown after 13K miles, so I scheduled an appt with local dealership. Three engine cycles later the light went out and codes went to ‘historical’ status.

When I got to the dealership, the check in guy said “if no current light, the we can’t help ya” and tried to send me on my way. I insisted they look at it and after a 5 min back and forth they agreed to bring it back and take a look.

Thirty min or so later they came back and said they just so happened to find a ‘software bug’ and reprogrammed the BSCM.

The service bulletin related to this bug was listed on work order: 20-na-155 (Image Attached)

Edited January 7, 2021 by Vickroy