Help Needed - B1000 Symptom 35 Trouble Code - SOLVED

[PG01]

I was able to cut out some time from the honey-do list items late yesterday afternoon, and I checked the two connections to the ECM, as suggested. Once I figured out how to disconnect the connectors, I saw that all of the pins were clean and straight. So, I reconnected the two connectors, and I cleared the ECM trouble code using the Tech 2. I will be driving around a bit today running errands, and upon completion, I will see if the ECM trouble code re-appears. (I expect that it will re-appear.)

I also tried to find the BCM, as that was suggested as the next item to check out the connectors, but I could not find the BCM. Granted, I did not take a lot of time trying to find the BCM, but any recommendations on where the BCM is specifically located on my 07 Yukon XL Denali would be very much appreciated.

tells you where bcm is Joseph...
The box to left of brake pedal is mbec(mid bussed electrical center) or something..... iirc or maybe I’m wrong... I ferget

 

[Joseph Garcia]

Hi Folks,

I have an update in my efforts to troubleshoot the B1000 Symptom 35 DTC.

I was able to find and access the BCM, and I removed each of the connectors, and each one had clean and straight pins. All wiring appears to be in good shape, as least as far a one can see from the clusters of wires taped together.

While I was there, I took a photo of the BCM part number, in case I need to replace it. This part number, 15943678, is not listed in Rock Auto or in GM Parts Direct, so I did a broad Google search. Turns out, this part number appears to be a re-manufactured Dorman unit.

I used the Tech 2 to reset the DTC codes, and I'll drive the truck around later today or tomorrow, in order to see if the code comes back (which I believe that it will).

If the code does come back, what are your recommendations for my next steps? Purchase an ACDELCO 25835966 BCM from Rock Auto?

I also took another photo of the Tech 2 DTC summary readout, and for the B1000 Symptom 35 code, it has DLC Pin: 14, 6 at the bottom of the readout. Any idea what this is, and is it something that would be useful to me for additional troubleshooting?





Thoughts and suggestions welcome.

 

[Doubeleive]

Hi Folks,

I have an update in my efforts to troubleshoot the B1000 Symptom 35 DTC.

I was able to find and access the BCM, and I removed each of the connectors, and each one had clean and straight pins. All wiring appears to be in good shape, as least as far a one can see from the clusters of wires taped together.

While I was there, I took a photo of the BCM part number, in case I need to replace it. This part number, 15943678, is not listed in Rock Auto or in GM Parts Direct, so I did a broad Google search. Turns out, this part number appears to be a re-manufactured Dorman unit.

I used the Tech 2 to reset the DTC codes, and I'll drive the truck around later today or tomorrow, in order to see if the code comes back (which I believe that it will).

If the code does come back, what are your recommendations for my next steps? Purchase an ACDELCO 25835966 BCM from Rock Auto?

I also took another photo of the Tech 2 DTC summary readout, and for the B1000 Symptom 35 code, it has DLC Pin: 14, 6 at the bottom of the readout. Any idea what this is, and is it something that would be useful to me for additional troubleshooting?

View attachment 255629

View attachment 255630

Thoughts and suggestions welcome.

the scanner is referencing the obd port pin's 14/6 low speed canbus and high speed canbus

 

[Joseph Garcia]

the scanner is referencing the obd port pin's 14/6 low speed canbus and high speed canbus

OK. So, it does not really provide me with any additional information that I can act on?

 

[Doubeleive]

OK. So, it does not really provide me with any additional information that I can act on?

not from what i can tell, but I think you can run a test on the bcm, if not you can run a test on the all the modules that and would include the bcm that may provide more detailed information
I take it you removed the factory radio and amp? no trailer brake controller? (tbcm)

 

[Joseph Garcia]

@Doubeleive "I take it you removed the factory radio and amp? no trailer brake controller? (tbcm)" Yes, correct. I gutted the entire Bose system and replaced it with an aftermarket system. Yes, there is no trailer brake controller. As such, I think that I can ignore those 'No Comm' entries on the Tech 2 diagnostics.

Update: I just took the truck out for a short drive, and when I returned, the B1000 Symptom 35 DTC was back. So, my disconnect/reconnect of the BCM's connectors did not resolve the issue.

Is it time for me to replace the BCM?

 

[OR VietVet]

@Doubeleive "I take it you removed the factory radio and amp? no trailer brake controller? (tbcm)" Yes, correct. I gutted the entire Bose system and replaced it with an aftermarket system. Yes, there is no trailer brake controller. As such, I think that I can ignore those 'No Comm' entries on the Tech 2 diagnostics.

Update: I just took the truck out for a short drive, and when I returned, the B1000 Symptom 35 DTC was back. So, my disconnect/reconnect of the BCM's connectors did not resolve the issue.

Is it time for me to replace the BCM?

At $173 plus shipping, is it worth it to just swap it out? $203 and free shipping at Amazon

 

[Doubeleive]

according to definition it is a fault in the ecu
B1000 35 Electronic Control Unit (ECU) Performance ROM Integrity

Read more: https://www.autocodes.com/b1000_chevrolet.html

 

[Joseph Garcia]

according to definition it is a fault in the ecu
B1000 35 Electronic Control Unit (ECU) Performance ROM Integrity

Read more: https://www.autocodes.com/b1000_chevrolet.html

Yes, I know, and that is a source of indecision on my part. There are references for this DTC as being related to an ECU issue out on the web, but there are just as many references to it being related to a BCM issue, out on the web. I checked with Justin at Black Bear Performance, and he seemed to believe that it was not directly related to the ECU, but rather it may be triggered from an interaction with another control module (BCM?).

I guess that I'll roll the dice and replace one of them. In the end, with my luck, I'll probably end up replacing both, as when I am faced with a 50/50 decision, 9 times out of 10, I generally make the wrong selection.

I'll keep you all updated. Thanks again for all of your continuing support.

 

[exp500]

Joseph, my experience on BCM/ECU error codes are pure programming. Before you pull the trigger on replacing either, reset Both. Make sure you Backup before. Sometimes when replacements are used, the used car lots just want the light off. not problem fixed. The factory service manual will be a BIG help here. The pre-programmed modules are generally done with other than factory tools Soooo...... sometimes there is an error. Your tech 2/laptop should be an easy fix.... But the caveat is sometimes the procedure doesn't complete correctly. Around the point of "turn ignition off then back on". If after a few tries of that not working, try starting the truck. Thats worked for me on several problem children lately. Hope this helps.