First off. I have seen this somewhat talked about on here, but the thread got long and vague and I’d like to bring it back around to get some straight answers. I own a hybrid battery repair company here in California, (which for the time being will remain anonymous), and I’m encountering about 100-130 cars per month right now. I have done everything from the gen 1 prius to the RAV4 hybrid, so I’m not a consumer nor am I a novice. But I am stumped here, because GM hybrids are a pain in the rear.

I have a customer that lives 7 hours away from our shop, barely in California, and they have an Escalade Hybrid with a bad HV battery. We do not have tech 2 (I ordered a Chinese one online). I do have a snap on scanner, but the day my tech went out and experienced the problem I will divulge after this sentence, he didn’t have it with him, since it’s rarely needed as customers are required to diagnose their stuff before we arrive.

The car has been sitting for a year, and I was told from the customer that the car was diagnosed as a bad HV from the dealer. I know him mutually, so I trust his word. When we showed up, his 12v battery was dead, so we had him bring one back from the dealer and put it in. The car still would not start. We went ahead and replaced the battery, with a tested (for internal resistance, matched capacity, and voltage) complete battery we assembled at our shop. The car would not start. I was stumped (communicating with my installer on the site) and wanted to rule out the potential of a battery bad battery computer in our core, or something else messed up (I have found shorts in the service plug contactor wires, the ones that split the battery in half, before). So my guy took our entire module pack (40) out and put them in customer’s pack. Car still did not start.


I have read on here that a module could be bad from an improper jump start, which makes sense because the customer admitted to jump steering it starting it a few times as for a while Covid put him out of work and he couldn’t afford the 12v battery or a new HV.

Any help pointing to this fix would be great. For the time being, I won’t have access to tech 2 unless I can bribe a local GM tech. It’s coming from China and will take another few weeks. Trying to get this guy back on the road and get paid.

thanks, Dirt

 

Any codes you can provide, even if not from a Tech 2 scanner?
Hard to provide advice without any codes to start with. What does "The car would not start" mean? No ICE turning over? Absolutely dead? Check to make sure the HVIC circuit is still intact. The orange plug has small contacts that complete a circuit .This circuit, if open, will not allow the truck to start. The battery terminal cover also has another jumper that completes the circuit. check that as well.

 

check the fuses
esp the 60 amp fuse for the AUX pump


the engine is started from the HV battery only and the 12v+ has to be in good shape as well..


do you hear the relay click in the HV battery? when the key is turned to the "on position "..



just wondering how much you charge for a replacement as i'm in the market for having mine pack refurbished/replaced soon


there might be another engine issue the guy has not told you about



Have you tried remote starting it??

 

I am going back with my snap on scanner since apparently tech 2 isn’t shipping due to covid. I have made sure the orange plug is locked in there properly. I have done a ton of these and have made that mistake before, but then inserted it properly and it worked.

And yes, ICE engine will not start. I am pretty sure it has the safety lockout measure now where you have to replace the module (can’t think of the name) and reprogram with tech 2.