Help! Fault Codes Read by Dealer and They are "researching"

[Richard Ames]

HVAC B1000, B0248 and B3748
IPC B2861, U1041, I1088, U1193, U1153, U1024,U1054, U1017 and U1301

Seems these are "communication faults" the dealer does not have a lot of experience working on Corvettes and I did not buy the care from them so any ideas or feed-back will be appreciated.

The dealer personel are friendly and seem to be trying but so far have not found anything.

 

[VetNutJim]

HVAC B1000, B0248 and B3748
IPC B2861, U1041, I1088, U1193, U1153, U1024,U1054, U1017 and U1301

Seems these are "communication faults" the dealer does not have a lot of experience working on Corvettes and I did not buy the care from them so any ideas or feed-back will be appreciated.

The dealer personel are friendly and seem to be trying but so far have not found anything.

Sorry, Don't have a clue as to what model Corvette you have, year of production or anything else. The following are some codes I looked up for the C5 Vette.
Some of your codes are NOT in the C5 DTC listings. It would be most helpful for anyone trying to help you to give as much information to them as possible.
Since you didn't say and because I didn't find several of your codes in the C5 DTC list, I'm guessing you have a C6? Maybe????


All "B" prefix codes are issued by the BCM.
The "U" prefix codes are communication error codes on the CAN bus between all the computers on the car.

B1000
B0248 Air Flow Control Circuit 3
B3748

IPC B2861

U1017
U1024
U1041
U1054
U1153 Loss of Communications with HVAC
U1193
U1301 Class 2 Circuit Shorted To Battery

I'll take a SWAG at it with the very small amount of information given......
The battery is mounted over one of the computers, directly above it. There have been cases where the battery leaked electrolyte onto that computer, wire harness and connectors. This has in some cases causes wreaked havoc with the functioning of the communication between control modules on the Corvette.
Maybe have your service professionals take a look there for trouble.
U1301 indicates a problem with a wire harness or connector with the Class 2 Buss Communication line shorted to the battery.
If the car has been in an accident this could have occurred. If the harness has been damaged by battery acid it also could be the cause.

Think I would look for that U1301 fault, fix that and then check codes again. Splice Pack SP205 or SP208 may be involved. There is a procedure in the FSM describing how to use the TECH II to check this.

There's just not enough background information to go much farther on.
Good luck with it.

 

[Richard Ames]

It's a 2013 GS with under 8500 miles with no collision history. Sorry I would put it in my profile.

 

[Richard Ames]

The HVAC Head started blinking again and I took it to the dealer and they agreed to replace it.

 

[Hib Halverson]

It was said above that the battery is above a computer. That is true of C5s but not of C6es.

The ECM in a C6 is just to the rear of the top of the right front inner fender, ahead of the battery.

Also, the code definitions posted, if they are for a C5, may or may not apply to a C6.

I'll add that if the dealer does not have much experience working on Corvettes and you have a myriad of electrical problems (likely caused by a short to the class 2 bus in one of the control modules) I'd go find a dealer which can work on Corvette electrical systems. With the combination of the below problems, I'd not let an inexperienced dealer do the work, however, if you have no choice, without seeing the car and reading that combination of problems, the first place I'd look for trouble is in the class 2 data system which is much easier said than done due to the number of modules which communicate via class 2.

As for the codes:
B1000 ECM communications or internal fault
B0248 fault in air flow control 3 circuit
B3748 air flow control 3 feed back circuit range or performance fault
B2861 unknown
U1017 communications loss with ECM
U1024 communications loss with TCM
U1041 comm. loss with EBTCM
U1054 unknown
U1153 comm. loss with climate control panel
U1193 comm. loss with remote control door lock receiver
U1301 class 2 data high aka class 2 shorted to battery.

If you're thinking about trying to fix this DIY, don't even think about it unless you have the Factory Service Manual which you can get from CAC sponsor Zip Products.

Also, I would try PM'ing c4c5specialist and see if he can post to this thread.

 

[Hib Halverson]

It was said above that the battery is above a computer. That is true of C5s but not of C6es.

The ECM in a C6 is just to the rear of the top of the right front inner fender, ahead of the battery.

Also, the code definitions posted, if they are for a C5, may or may not apply to a C6.

I'll add that if the dealer does not have much experience working on Corvettes and you have a myriad of electrical problems (likely caused by a short to the class 2 bus in one of the control modules) I'd go find a dealer which can work on Corvette electrical systems. With the combination of the below problems, I'd not let an inexperienced dealer do the work, however, if you have no choice, without seeing the car and reading that combination of problems, the first place I'd look for trouble is in the class 2 data system which is much easier said than done due to the number of modules which communicate via class 2.

As for the codes:
B1000 ECM communications or internal fault
B0248 fault in air flow control 3 circuit
B3748 air flow control 3 feed back circuit range or performance fault
B2861 unknown
U1017 communications loss with ECM
U1024 communications loss with TCM
U1041 comm. loss with EBTCM
U1054 unknown
U1153 comm. loss with climate control panel
U1193 comm. loss with remote control door lock receiver
U1301 class 2 data high (aka class 2 shorted to battery).

If you're thinking about trying to fix this DIY, don't even think about it unless you have the Factory Service Manual which you can get from CAC sponsor Zip Products.

Also, I would try PM'ing c4c5specialist and see if he can post to this thread.

 

[Richard Ames]

It was said above that the battery is above a computer. That is true of C5s but not of C6es.

The ECM in a C6 is just to the rear of the top of the right front inner fender, ahead of the battery.

Also, the code definitions posted, if they are for a C5, may or may not apply to a C6.

I'll add that if the dealer does not have much experience working on Corvettes and you have a myriad of electrical problems (likely caused by a short to the class 2 bus in one of the control modules) I'd go find a dealer which can work on Corvette electrical systems. With the combination of the below problems, I'd not let an inexperienced dealer do the work, however, if you have no choice, without seeing the car and reading that combination of problems, the first place I'd look for trouble is in the class 2 data system which is much easier said than done due to the number of modules which communicate via class 2.

As for the codes:
B1000 ECM communications or internal fault
B0248 fault in air flow control 3 circuit
B3748 air flow control 3 feed back circuit range or performance fault
B2861 unknown
U1017 communications loss with ECM
U1024 communications loss with TCM
U1041 comm. loss with EBTCM
U1054 unknown
U1153 comm. loss with climate control panel
U1193 comm. loss with remote control door lock receiver
U1301 class 2 data high (aka class 2 shorted to battery).

If you're thinking about trying to fix this DIY, don't even think about it unless you have the Factory Service Manual which you can get from CAC sponsor Zip Products.

Also, I would try PM'ing c4c5specialist and see if he can post to this thread.

Thanks for your input and suggestion to PM c4c5specialis but he is not allowing them.

 

[c4c5specialist]

HI there,

U prefixed numbers are communications ONLY. B prefix shows a fault of a component.

#1, when did this occur? Did you just start the car? Had you been driving a while? What other work has been done to the vehicle prior to this incident?

#2, 2013 GS, I would need to know if you have a manual transmission or not, because that changes battery location and also electrical wiring.

#3, based on the codes given, there are a number of things I would disregard. U1301 is the ONLY communications code I would focus ON, all the other U codes are loss of communications with OTHER control modules. A U1301 would CAUSE every other one of those codes.


HVAC, now how was it performing PRIOR to this event? Correct temperature output from the vents? Correct air flow from correct locations, such as floor/vent/defroster???


B1000 indicates a fault within a computer component BUT THERE SHOULD BE A SUBCODE, either 00 or 31 or 57 which would indicate the TYPE OF FAILURE. Details were missed.

As for the rest, B2861 is an invalid code and does not appear on ANY GM diagnostic charts, so maybe that is a typo.


An HVAC control head is a guess and it can be theorized that it may work. But I am more to checking actual wiring to and from the control modules themselves prior to dictating replace ment on a theory.


UNLESS, no other evidence can be found of a problem.

Allthebest, Paul

 

[Richard Ames]

Thank you Paul it has an automatic transmission and is the coupe. Battery is at the rear of the right front wheel well. The blinking HVAC seems to start after driving a while and does not clear until I have sat overnight in our garage. Turning the car off and walking away for several minutes does not correct the blinking when I restart the automobile. The system seems to function normally while doing the blinking.

The Sub Code on the B1000 is 00

I purchased the car with 6800 miles and has only had normal maintenance to date with no mods.

Saturday it was after driving about 80 miles, drove the car yesterday without a blinking HVAC head and it started blinking this AM about 4 to 5 seconds after starting the engine. Controls are operable when the condition exists.

 

[c4c5specialist]

Hi there,

I would first confirm that there are no chaffed wires on the back of the HVAC control head.

Second, when the system is flashing the LED, I would scan the system to confirm loss of communications with the HVAC control module, or ANY OTHER MODULE AS WELL.

Remember that the communications line in this case has multiple modules so ANY OF THOSE MODULES can create your condition of no communications. HERE is the key, it is the module that does NOT set the code, that is usually the cuprit. This is why a DTC check of the ENTIRE vehicle is more important than ANYTHING when diagnosing this condition.

Allthebest, Paul

 

[Richard Ames]

Thank you Paul you are an asset to this forum

 

[Richard Ames]

The HVAC head is at the dealership but the mechanic assigned is out sick. Also no symptoms since last Monday. Thinking of waiting for another failure?

 

[c4c5specialist]

HI there,

I would not wait. Control module calibrations are specific and there may be new ones inside the control head.

Not only that, but if they inspect the wiring accurately, they might find something else.

You have spent alot of hard earned money on your car, let GM stand behind it!

Allthebest, Paul

 

[Richard Ames]

Update: in the dry no problems: But it rained on it tonight and upon start up the ABS, Traction Control, Stability Control lights stayed on along with the blinking HVAC head and messages to Service Engine Soon, along with service all the above items soon.

Local Chevrolet Dealer Said they do not have the equiptment to deal with it and to go to a "Corvette" store so have an appointment with a larger dealer tomorrow.

 

[catbert]

It's probable that the dealer is missing a clue more than equipment. Hope the next dealer can fix it for you. good luck.

 

[Richard Ames]

Took to Palm Chevrolet, Punta Gorda, FL this AM and was impressed by the "professional" attitude and the recently remodeled service area. They diagnosed a fan control and a body control modules needs replacing. Supplied a Tahoe loaner till parts received and installed by mid week.

 

[Hib Halverson]

Took to Palm Chevrolet, Punta Gorda, FL this AM and was impressed by the "professional" attitude and the recently remodeled service area. They diagnosed a fan control and a body control modules needs replacing. Supplied a Tahoe loaner till parts received and installed by mid week.

Now THAT's what I'm talkin' about.

Here's to Palm Chevy.

 

[LLC5]

Took to Palm Chevrolet, Punta Gorda, FL this AM and was impressed by the "professional" attitude and the recently remodeled service area. They diagnosed a fan control and a body control modules needs replacing. Supplied a Tahoe loaner till parts received and installed by mid week.

When you have the modules replaced it would be a good idea to request that the tech look for any moisture in those areas, and if he states that they were dry, it would also be a good idea request that the dealer contact GM tech support and ask them why it only acted up after it had rained. Good luck with your repairs.

 

[Richard Ames]

Update

Picked up the Corvette today and they have replaced a ton of modules including wheel sensors etc. all wiring checks out. They drive it around and the intermittent HVAC head is blinking again so they have ordered that to replace also. Wish I could show you the look on the service guy's face after he had coached me on how to completely satisfied on the survey and this happened. I feel blessed that it happened and we may slay the electrical grenlin. It was not the dealer service people's fault as these kind of problems are the hardest to fix.

 

[Richard Ames]

Replaced the HVXC head tody. I had a 1:15 appointment and was out by 2PM. All seems well. Waiting for the rain test to feel 100%.