Could This Be a BCM Issue?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

OP
OP
YukonRog

YukonRog

Full Access Member
Joined
Jun 25, 2020
Posts
594
Reaction score
752
Location
Grass Valley CA
So just now seeing this... If I read the thread right you have an 05? I have an 05 Yukon. On mine the TPMS is part of the passenger door module. Last time I tried the relearn it failed over and over on the last wheel. In my case I was fortunate to have the sensor ID numbers and I was able to use an OBD2 adapter and write the values to the correct location myself.
Interesting. I don't have a Tech 2 only a Launch Millennium 90. No codes. It only does so much bidirectional too. I'll have to research that.
 

TJ Baker

Full Access Member
Joined
Mar 5, 2018
Posts
163
Reaction score
138
Interesting. I don't have a Tech 2 only a Launch Millennium 90. No codes. It only does so much bidirectional too. I'll have to research that.


I found the Tech2 fairly useless here.

I actually used one of those $15 bluetooth adapters. That and a serial terminal app. It happens to be a hobby of mine, fiddling with the old GM single wire serial data stuff.
 

TJ Baker

Full Access Member
Joined
Mar 5, 2018
Posts
163
Reaction score
138
Too bad my girlfriend sold the Penn Valley place or I could assist. Way out in Colorado now.
 
OP
OP
YukonRog

YukonRog

Full Access Member
Joined
Jun 25, 2020
Posts
594
Reaction score
752
Location
Grass Valley CA
I found the Tech2 fairly useless here.

I actually used one of those $15 bluetooth adapters. That and a serial terminal app. It happens to be a hobby of mine, fiddling with the old GM single wire serial data stuff.
Sounds like computer programming to me. What did you use with the bluetooth?
 

TJ Baker

Full Access Member
Joined
Mar 5, 2018
Posts
163
Reaction score
138
Sounds like computer programming to me. What did you use with the bluetooth?


As I mentioned I used a serial terminal app. I have learned to speak the language of the network and can just send the right messages to the passenger door module instead of paying for some fancy softwares to do it for me! The lucky part was having previously read out the block memory locations of the PDM so I had the TPMS ID##s on record.

So it really was just typing in few lines like...

ATSH6CA1F1
3BD88FE5F38FE615
 
OP
OP
YukonRog

YukonRog

Full Access Member
Joined
Jun 25, 2020
Posts
594
Reaction score
752
Location
Grass Valley CA
As I mentioned I used a serial terminal app. I have learned to speak the language of the network and can just send the right messages to the passenger door module instead of paying for some fancy softwares to do it for me! The lucky part was having previously read out the block memory locations of the PDM so I had the TPMS ID##s on record.

So it really was just typing in few lines like...

ATSH6CA1F1
3BD88FE5F38FE615
Easy for you! I can reprogram a map for my Harley and change AFR's and Stoichometric Values and timing, create spread sheets and things like that but I cant write programs. Guess if I learned it maybe. But here's my question, the keyless fobs work, would just the TPMS Receiver go out in that RCDLR?
 

TJ Baker

Full Access Member
Joined
Mar 5, 2018
Posts
163
Reaction score
138
Easy for you! I can reprogram a map for my Harley and change AFR's and Stoichometric Values and timing, create spread sheets and things like that but I cant write programs. Guess if I learned it maybe. But here's my question, the keyless fobs work, would just the TPMS Receiver go out in that RCDLR?

Well that isn't a program, just a couple messages. The first line sets the header for the OBD2 adapter to send when the following message is sent. In 3 bytes it contains the message type, target of the message and sender of the message. The second line sends two sensor ID#s, front left and front right to memory block D8.


I cannot say I know which module contains the keyfob components on the Yukon !! On my TrailBlazer it is the liftgate module. Maybe I'll have a look tommorow.
 

TJ Baker

Full Access Member
Joined
Mar 5, 2018
Posts
163
Reaction score
138
Check your door switch functions on both drivers and passenger doors.

If you disturbed the communications wiring between them this would happen because the messages from the passenger door module where the keyfob and TPMS fumctions reside could then not get to the BCM.
 

Forum statistics

Threads
129,117
Posts
1,810,709
Members
92,203
Latest member
firedog9518

Latest posts

Top