2009 Tahoe LTZ U00730 code, Transmission goes into limp mode.

[Gaddy09tahoeltz]

Hi guys, new here and first post- that being said if i screw something up Edi quite wise please let me know respectfully.
My 09 POS is throwing a U00730 in the TCM.

U0073 Code: Control Module Communication Bus “A” Off​

I found this in one of GM upfitters wiring books online

-This code is mapped on the Tech 2 screen as a code against the physical device. A lost communication DTC typically is set in modules other than the module with a communication failure.

-I can communicate with all the modules and do bidirectional testing' everything seems fine.
Im also setting a B1001-46 Option configuration error in the VCIM

B1001 Chevrolet Code - SDM Option Configuration Error

-I have no airbag light on.
-When i go to configure the SDM in the BCM it says the numbers match and is not needed.

Parts replaced to this point-
-Negative battery cable- broke almost in half at R/F frame ground point.
-Fixed chaffed wire for the ect sensor on top engine harness.

No fix yet. I've gone through all the wiring for chafes, broken or pinched wires per TBS
I'm at a loss and could use a few ideas bounced around.
thanks in advance

 

[Doubeleive]

Hi guys, new here and first post- that being said if i screw something up Edi quite wise please let me know respectfully.
My 09 POS is throwing a U00730 in the TCM.

U0073 Code: Control Module Communication Bus “A” Off​

I found this in one of GM upfitters wiring books online

-This code is mapped on the Tech 2 screen as a code against the physical device. A lost communication DTC typically is set in modules other than the module with a communication failure.

-I can communicate with all the modules and do bidirectional testing' everything seems fine.
Im also setting a B1001-46 Option configuration error in the VCIM

B1001 Chevrolet Code - SDM Option Configuration Error

-I have no airbag light on.
-When i go to configure the SDM in the BCM it says the numbers match and is not needed.

Parts replaced to this point-
-Negative battery cable- broke almost in half at R/F frame ground point.
-Fixed chaffed wire for the ect sensor on top engine harness.

No fix yet. I've gone through all the wiring for chafes, broken or pinched wires per TBS
I'm at a loss and could use a few ideas bounced around.
thanks in advance

have you checked the transmission harness? there is a tsb for that as well, some of the pins can work there way loose causing a variety pack of problems.

 

[Gaddy09tahoeltz]

have you checked the transmission harness? there is a tsb for that as well, some of the pins can work there way loose causing a variety pack of problems.

yes. we are refering to the same 18 page TSB gm put out

 

[Doubeleive]

fuse box & fuses? be sure the fuse box seated properly and/or has no corrosion

 

[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.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[swathdiver]

Hi guys, new here and first post- that being said if i screw something up Edi quite wise please let me know respectfully.
My 09 POS is throwing a U00730 in the TCM.

U0073 Code: Control Module Communication Bus “A” Off​

I found this in one of GM upfitters wiring books online

-This code is mapped on the Tech 2 screen as a code against the physical device. A lost communication DTC typically is set in modules other than the module with a communication failure.

-I can communicate with all the modules and do bidirectional testing' everything seems fine.
Im also setting a B1001-46 Option configuration error in the VCIM

B1001 Chevrolet Code - SDM Option Configuration Error

-I have no airbag light on.
-When i go to configure the SDM in the BCM it says the numbers match and is not needed.

Parts replaced to this point-
-Negative battery cable- broke almost in half at R/F frame ground point.
-Fixed chaffed wire for the ect sensor on top engine harness.

No fix yet. I've gone through all the wiring for chafes, broken or pinched wires per TBS
I'm at a loss and could use a few ideas bounced around.
thanks in advance

To solve you are going to need a bi-directional scan tool and the shop manual. U0073 should have a symptom code as well, either 71 for ECU High Speed Bus Off, 72 for ECU Low Speed Bus Off or 00 Control Module Communication Bus Off.

This is a wiring issue or module/computer failure.

The colored and interactive diagrams at AllDataDIY may prove useful for this one.

As for the SRS code, I had one like that too recently and it worked itself out. They can be set by low/erratic voltage or corroded sensors.

 

[Gaddy09tahoeltz]

fuse box & fuses? be sure the fuse box seated properly and/or has no corrosion

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.

You are already receiving sage advice from the knowledgeable folks on this Forum.

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.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[Gaddy09tahoeltz]

To solve you are going to need a bi-directional scan tool and the shop manual. U0073 should have a symptom code as well, either 71 for ECU High Speed Bus Off, 72 for ECU Low Speed Bus Off or 00 Control Module Communication Bus Off.

This is a wiring issue or module/computer failure.

The colored and interactive diagrams at AllDataDIY may prove useful for this one.

As for the SRS code, I had one like that too recently and it worked itself out. They can be set by low/erratic voltage or corroded sensors.

UPDATE-
I believe I’ve got this one figured out!!

I do have a bi-directional scanner( it’s the only way I would have figured this out).

going through all the modules one at a time checking for updated software and coding issues within the modules I happened to be watching the BCM info and when I plugged in my cell phone to charge it in the cigarette lighter port the BCM went haywire- relays clicking for no reason, transmission went to limp mode and MIL came on.
BCM was loosing connection with tcm and various other modules. Ebcm,vcim.
Watching live data Bcm was loosing stored VIN intermittently and the traceability numbers intermittently. Changed charging ports and cleared codes. Problem stopped, used different chargers in the cigarette lighter port and no problem, put my original charger back in the cigarette port and instant problem again. Charger has an internal issue and I threw it away. No problems since.

 

[Geotrash]

UPDATE-
I believe I’ve got this one figured out!!

I do have a bi-directional scanner( it’s the only way I would have figured this out).

going through all the modules one at a time checking for updated software and coding issues within the modules I happened to be watching the BCM info and when I plugged in my cell phone to charge it in the cigarette lighter port the BCM went haywire- relays clicking for no reason, transmission went to limp mode and MIL came on.
BCM was loosing connection with tcm and various other modules. Ebcm,vcim.
Watching live data Bcm was loosing stored VIN intermittently and the traceability numbers intermittently. Changed charging ports and cleared codes. Problem stopped, used different chargers in the cigarette lighter port and no problem, put my original charger back in the cigarette port and instant problem again. Charger has an internal issue and I threw it away. No problems since.

I've heard of this happening before. Some USB chargers generate so much EMF interference that it actually messes with the electronics in the vehicle. Do you remember what brand it was and what it looked like so we can all avoid it?

 

[Joseph Garcia]

UPDATE-
I believe I’ve got this one figured out!!

I do have a bi-directional scanner( it’s the only way I would have figured this out).

going through all the modules one at a time checking for updated software and coding issues within the modules I happened to be watching the BCM info and when I plugged in my cell phone to charge it in the cigarette lighter port the BCM went haywire- relays clicking for no reason, transmission went to limp mode and MIL came on.
BCM was loosing connection with tcm and various other modules. Ebcm,vcim.
Watching live data Bcm was loosing stored VIN intermittently and the traceability numbers intermittently. Changed charging ports and cleared codes. Problem stopped, used different chargers in the cigarette lighter port and no problem, put my original charger back in the cigarette port and instant problem again. Charger has an internal issue and I threw it away. No problems since.

Thank you for posting the solution to your issue. Our collective knowledge base has been increased.