Jeez that is disappointing. I am not sure what area that you are in (sounds cold so must be way up North LOL) but I would be tempted to try to find an Independent Hybrid Specialty shop and let them do a diagnosis. Sometimes plain ole common sense and experience in dealing with multiple similar vehicles will be stronger than a GM Cubicle monkey specialist that has only seen a Hybrid vehicle from a distance..................

 

Update: I am still getting "service hybrid system" on the DTC, but it clears and stays off for the drive with the check button. I don't get any other symptoms, but the symptoms I did have are no longer there. I disconnected the 12V battery for 15 minutes in a warm, 60 degree, garage, but the message is still there. Next is to disconnect the 12V then the 300V emergency disconnect to see if the Serial Data Gateway Module resets. It hasn't been above 51 degrees for 24 hours yet so I don't know if it will clear when the temperature soak is high. The dealer says the SDGM is bad and needs to be replaced, but they are no longer produced so a new one would have to be built for $500+. I can get a salvage one for $100, but they will not program it. The GMC customer care division would not refer me to an engineer that is familiar with the system and said I had to go back to my dealer. This is ridiculous. Since I am not seeing any other symptoms I guess I just have to live with the error message.

 

Have you ever noticed hard steering effort when it is on?

 

Nope no other symptoms. In fact today it was above 51 degrees and message still came on. I think it is ghost message and entire system needs to be cleared of all history. I'm hoping if I disconnect all power from the computers for a period of time they will all reset, but I'll bet there is non-volatile memory involved.

 

Hi! Had same problem week ago. Message "service hybrid system " has been on dash mornings only, than it start showing up every 30 min or so. Dealer found Sgm b1000-39 code and quoted me 1400$ to replace Serial data Gateway module and they need to order part also. I were not able to found new module, seems like there's now one in county has it, so I ended up pulling one from wrecked hybrid tahoe and my friend did programmed it for me. Replacing took 40 min and used module cost me 50$

 

Ivan, did you go through this bulletin with your dealer? https://gm.oemdtc.com/TSB/SB-10057008-5045.pdf

After the dealer replaced the APM per the bulletin the repeated messages during the day went away. Now all I have is a one time message at start up that is cleared and never returns regardless of temperature unless I have to restart. I disconnected the hybrid battery and the 12V battery overnight and it did not reset. I'm pretty sure this is a residual message in history, but the dealer says it is the SDGM. Doesn't it require the GMC computer to program the SDGM? The dealer will not program a salvaged one and wants, like you said, over $1000 and would have to have one manufactured.

 

Hi! No, I never seen that bulletin. Guy with laptop, universal programer and gm soft subscription can program with no issues. Mechanical replacement is even easier. Ask your dealer how long it would take to get new module, since I didn't found single new one in whole country.

 

I know this is old but hopefully can help someone else - I had the same code (B1000-39), ordered the module listed above from local dealer (had it next day), installed it and had dealer program for $155. Fixed the issue and the car is back on the road!

 

Just wanted to update this thread. Still have "Service Hybrid System" on DTC, but no other systems and message is cleared every time I start it. I can't get a dealership nor GM to clear the code at no charge.

 

lvflyer, are you still having the "Service Hybrid System" on DTC come on, did it finally go away or have you seen any other trouble? Also in one of your posts above you referred to symptoms going away after the APM was replaced "battery voltage". Were you referring/watching the 12 v battery voltage on the DIC or the Hybrid battery voltage through an ODBII app? My 2013 Yukon that ,SKeith ran a grid on my battery data and said it is the best he has ever seen on a used GM battery at 120k, Data looks like a new battery. It has posted the "Service Hybrid System" on DTC about 6 cold mornings (51 degree today, but mostly 20-30 F) now over the last 3 weeks. It goes away on its own as the car warms up. The next day is warm and it does not happen. Never had any other symptoms ie: brakes, steering. mpg about 18-19 in town, heavy foot: hwy about 20-22 mpg. 12 V battery is 14 months old but reads 12.48 and 12.50 v on two different meters, resting overnight.

Comments or pontifications (SKeith) welcome