Correlation between U0422-71 and P0471

[Dirtystoker]

Hello all first post ever. 2016 sierra 2500hd CC,LB,work truck.

 

Both codes flagged on same drive cycle. Before I drop the trans pan, im going to rule out canbus. I feel that this comms error could prevent tcc lock up. Has anyone seen this before as I can't find any source that says this can happen but when I break it down to first principles, I can find a correlation. Any input or thoughts would be helpful. Thanks y'all. PS im canadian and love my neighbours to south. I also notice a lot of questions about trans temp and want to say if something doesn't make sense about operating temp try changing units on your display!!!

[newdude]

1 hour ago, Dirtystoker said:

Hello all first post ever. 2016 sierra 2500hd CC,LB,work truck.

 

Both codes flagged on same drive cycle. Before I drop the trans pan, im going to rule out canbus. I feel that this comms error could prevent tcc lock up. Has anyone seen this before as I can't find any source that says this can happen but when I break it down to first principles, I can find a correlation. Any input or thoughts would be helpful. Thanks y'all. PS im canadian and love my neighbours to south. I also notice a lot of questions about trans temp and want to say if something doesn't make sense about operating temp try changing units on your display!!!

 

 

Do you mean P0741 instead of P0471?

 

What module is setting the U0422?

[Dirtystoker]

Here are the codes from my innova sd29. At first they dont seem related but im thinking that if the bcm sends a corupt packet or signal to the tcm or not at all because the ebcm signal was not read properly that tcm might not lock because it doesnt know the wheel speed or brake position preventing the lockup

[carkhz316]

Your code reader is either not reading body codes, or its not reading the BCM. It won't have anything to do with the transmission. Unless you have an ABS warning or some other fault, I would disregard and instead pursue the transmission issue as a primary focus.

[Dirtystoker]

Ok thanks. Do you know the communication logic on these platforms? If so any chance you could explain, or provide a sketch of how each module sends and receives to each other?

[davester]

get a subscription to alldata.com for your truck and read up on it yourself.  it also includes vehicle-specific diagnostic and repair procedures for those codes.

[Dirtystoker]

Thanks

[newdude]

On 3/25/2026 at 9:34 PM, Dirtystoker said:

Here are the codes from my innova sd29. At first they dont seem related but im thinking that if the bcm sends a corupt packet or signal to the tcm or not at all because the ebcm signal was not read properly that tcm might not lock because it doesnt know the wheel speed or brake position preventing the lockup

 

 

 

 

The U0422 would be a separate issue that needs a scanner that can read the whole truck.  Your SD29 only does engine and ABS. 

 

P0741 sets only for mechanical or hydraulic failure of the TCC hydraulic circuits or the torque converter itself.  Probably needs a torque converter.  

DTC P0741

Torque Converter Clutch (TCC) System – Stuck Off – Transmission Hydraulic/Mechanical Performance