2021 Tahoe CEL (P00ff and U1962)

[kjohns339]

Hi all, new to the forum.

I have a 2021 Tahoe LT 5.3 and my CEL came on recently. Pulled the codes and I’m getting P00FF and U1962. Truck runs and drives fine.

I’ve read these may be related to OnStar/telematics rather than a drivability issue. I also noticed intermittent in vehicle Wi-Fi issues a few weeks ago.

Has anyone experienced this, know how to troubleshoot, or the likely fix? Appreciate any insight.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally assist you with your issue, but other members of this Forum much more knowledgeable than me in this truck year series will chime in.

 

[Doubeleive]

Hi all, new to the forum.

I have a 2021 Tahoe LT 5.3 and my CEL came on recently. Pulled the codes and I’m getting P00FF and U1962. Truck runs and drives fine.

I’ve read these may be related to OnStar/telematics rather than a drivability issue. I also noticed intermittent in vehicle Wi-Fi issues a few weeks ago.

Has anyone experienced this, know how to troubleshoot, or the likely fix? Appreciate any insight.

how old is the battery?

 

[kjohns339]

how old is the battery?

Thanks for the quick reply!
I just replaced it maybe 2-3 months ago.

 

[Doubeleive]

Thanks for the quick reply!
I just replaced it maybe 2-3 months ago.

anything aftermarket installed?

 

[tsuintx]

Interesting that OnStar related issue will trigger CEL. OnStar has nothing to do with emissions anyway...

But yeah, sounds electrical power related issue.

 

[kjohns339]

anything aftermarket installed?

Aftermarket brake controller. It has been installed for 2 years without issue. I had read somewhere that the battery needed to be programmed? I've never heard of that before.

 

[Doubeleive]

Aftermarket brake controller. It has been installed for 2 years without issue. I had read somewhere that the battery needed to be programmed? I've never heard of that before.

No the battery does not need to be programmed, the errors you are getting however are often due to battery or power issue's.
one thing you could do just for a general place to start is check the resting voltage of the battery and wire brush the battery terminals/clean them up even if they look ok
these vehicles are very sensitive to voltage.
Other than that if the problem persists it's likely going to take a deeper diagnostic. there could be a loose connection on the radio/hmi module or something related.

 

[kjohns339]

No the battery does not need to be programmed, the errors you are getting however are often due to battery or power issue's.
one thing you could do just for a general place to start is check the resting voltage of the battery and wire brush the battery terminals/clean them up even if they look ok
these vehicles are very sensitive to voltage.
Other than that if the problem persists it's likely going to take a deeper diagnostic. there could be a loose connection on the radio/hmi module or something related.

Thank you for the help! I checked the battery voltage cold and it was only 12.2v. Started the truck and the voltage started building while running. The truck sat for a long weekend in the cold, my guess is that did enough to drain the battery and throw the code. It has also been driven less in last 6 months, so the battery may not be getting a chance to fully charge.

 

[Doubeleive]

Thank you for the help! I checked the battery voltage cold and it was only 12.2v. Started the truck and the voltage started building while running. The truck sat for a long weekend in the cold, my guess is that did enough to drain the battery and throw the code. It has also been driven less in last 6 months, so the battery may not be getting a chance to fully charge.

You can put a trickle charger on it if it not going to be driven very often

 

[Steve Smith]

My Onstar/cellular/WIFI module failed and I got those two codes.