Help with DTC U1040
Thread Starter
Intermediate
Joined: Feb 2020
Posts: 40
Likes: 10
From: Northern California
Help with DTC U1040
I've been working through a bunch of codes on my 03 C5, but this one has me stumped. SDM U1040. From what I gather there is a loss of communication from the System Diagnostic Module? (SDM) to the Traction Control System. Where, exactly, is the System Diagnotic Module?
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,717
Likes: 4,109
From: Cape Coral, Florida
The SDM (Sensing and Diagnostic Module) is basically your Airbag system...the module is underneath the center of the dash. U1040 is loss of comm with the TCS (EBCM)...I'd look at the EBCM power and grounds...that is usually the first step...check the harness connectors for corrosion and pin fitment...may even be a defective EBCM !!
Thread Starter
Intermediate
Joined: Feb 2020
Posts: 40
Likes: 10
From: Northern California
This makes sense as I currently have the dash torn out awaiting new HVAC Blend door actuators. I will check the ground and continuity while it's easily available. Thanks for the info!
Drifting
Joined: May 2007
Posts: 1,515
Likes: 14
From: Gig Harbor WA
EBCM fix
They do excellent work and provide any support you may need.
Le Mans Master
Joined: Jul 2010
Posts: 6,039
Likes: 732
He's not on the frome anymore. Just saying, don't wait foe a response baCK
