code u0073
07-31-2017 | 01:36 PM
#1
Thread Starter
Senior Member
Joined: 08-03-2010
Posts: 3,564
From: Lake Ronkonkoma, N.Y.
code u0073
It's happened 2 times now in a period of time in hot temperatures with the windows closed.
Control Module Communication Bus A Off.
When it happens where there is a no start I unplug/plug in the 50 amp fuse at the battery and it starts.
What lights up are the check engine light and the content theft-deterrent light.
After a couple of restarts the lights go out.
I'm going to say this is a dealer issue and not something I can repair.
Feed back with this?
I did find this:
Chevrolet Factory Service Bulletin OBDII Code U0073
Read more: https://www.autocodes.com/u0073_chevrolet.html
Control Module Communication Bus A Off.
When it happens where there is a no start I unplug/plug in the 50 amp fuse at the battery and it starts.
What lights up are the check engine light and the content theft-deterrent light.
After a couple of restarts the lights go out.
I'm going to say this is a dealer issue and not something I can repair.
Feed back with this?
I did find this:
Chevrolet Factory Service Bulletin OBDII Code U0073
Read more: https://www.autocodes.com/u0073_chevrolet.html
07-31-2017 | 01:57 PM
#2
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Joined: 10-13-2011
Posts: 37,828
From: Welland,Ont Canada
If we read the mentioned bulletin, check wire harness connections at the TCM.
I would also check all ground locations under the hood, squirrels live wires!
https://www.autocodes.com/uploads/gmc/08-07-30-021E.pdf
I would also check all ground locations under the hood, squirrels live wires!
https://www.autocodes.com/uploads/gmc/08-07-30-021E.pdf
07-31-2017 | 02:06 PM
#3
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Joined: 05-01-2014
Posts: 8,173
From: California
Oh boy, the CAN bus communication code, that's a tough one. Don't know if it matters, but that TSB doesn't list HHR. You're probably gonna need a tech2 diagnosis. You don't have an OBD2 reader plugged in all the time do you?
07-31-2017 | 02:09 PM
#4
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Joined: 01-23-2009
Posts: 25,339
From: Fredericksburg,VA
Has anyone messed with OnStar/XM/Sirius?
Has anyone messed with any connectors?
It is most likely a wiring or connector issue. The upshot of the diagnostic is "DON'T REPLACE ANY MODULE" because it is a COMMUNICATION fault.
I can print off the section for you in pdf.
Has anyone messed with any connectors?
It is most likely a wiring or connector issue. The upshot of the diagnostic is "DON'T REPLACE ANY MODULE" because it is a COMMUNICATION fault.
I can print off the section for you in pdf.
07-31-2017 | 02:28 PM
#5
Thread Starter
Senior Member
Joined: 08-03-2010
Posts: 3,564
From: Lake Ronkonkoma, N.Y.
Ok to answer all questions in order
OldBlue- No Rats/Squirrels live near me. If they did they would be dead. Also I would have to know where the TCM is located. I'm going to say that's for the transmission.
Randy- I have a AutoXray AX7000 Tech Scan but it stops at 2006. The tool works good for info and diagnostics. If I could upgrade it, it might help me.
Donbrew-No the car is a virgin 2010 SS bought from a dealer that certified it when it was bought with 20K, now has 40K.
OldBlue- No Rats/Squirrels live near me. If they did they would be dead. Also I would have to know where the TCM is located. I'm going to say that's for the transmission.
Randy- I have a AutoXray AX7000 Tech Scan but it stops at 2006. The tool works good for info and diagnostics. If I could upgrade it, it might help me.
Donbrew-No the car is a virgin 2010 SS bought from a dealer that certified it when it was bought with 20K, now has 40K.
07-31-2017 | 02:44 PM
#6
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Joined: 01-23-2009
Posts: 25,339
From: Fredericksburg,VA
Upgrading the scan tool only upgrades a few "manufacturer specific" OBDII items; The HHR has none.
Do you want me to print it out?
If you do take it to a dealership DO NOT LET THEM THROW PARTS AT IT. There is a procedure in the Factory Service Manual for identifying the exact section that is at fault. There is a tiny possibility that a module is bad.
The GM LAN is a circular daisy chain; if one module disappears from the network the entire network shuts down. So, you have to do a process of elimination game.
The TCM is right behind the ECM. There are photographs in the link oldblue posted.
Do you want me to print it out?
If you do take it to a dealership DO NOT LET THEM THROW PARTS AT IT. There is a procedure in the Factory Service Manual for identifying the exact section that is at fault. There is a tiny possibility that a module is bad.
The GM LAN is a circular daisy chain; if one module disappears from the network the entire network shuts down. So, you have to do a process of elimination game.
The TCM is right behind the ECM. There are photographs in the link oldblue posted.
08-01-2017 | 03:33 AM
#9
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Joined: 08-03-2010
Posts: 3,564
From: Lake Ronkonkoma, N.Y.
OK now I understand. Looks like a dealer repair.
When this code problem happens the only way I get it to restart is by R&R of the 50amp fuse by the battery.
Isn't that fuse for the BCM?
When this code problem happens the only way I get it to restart is by R&R of the 50amp fuse by the battery.
Isn't that fuse for the BCM?
08-01-2017 | 03:39 AM
#10
Thread Starter
Senior Member
Joined: 08-03-2010
Posts: 3,564
From: Lake Ronkonkoma, N.Y.