08 Hybrid At low speed jolt cutout lerch and get codes P061B & P0AC4

8 Hybrid Bump-n-Jump P061B & P0AC4
Well I'm another case study;Tahoe #2 for me upgraded from an 02 well at least i thought i was. I have been thankful i didnt sell it yet. only I have the persistant problem happens everytime i drive it now. When its just starting off in Elec mode the throttle feels dead and stalls but its the engine isnt running yet and it bucks violently before returninbg to normal/ So i brought it in and they found #1 cycinder fouled spark plug and added a quart of oil and told me the engine is shot and to replace it.
i couldnt believe what i was hearing. So the second time i brought it to thwem i asked them to check the aux trasnsmission fluid pump and they denied me and said i needed to replace the engine first! bastards So Maher Chevrolet in St Petersburg sucks. I normally do all my own repairs but this one i am hessitant

So after hearing all the different cases with the same exact problem at least it seems to be. The one item that seems most logical is the Aux. transmission fluid pump. It only runs when the vehicle is in EV in Elec. mode, and that transmission is very particular and needs lube always. and with the engine not running it needs that secondary pump to take over. I'm not to clear on the snap ring issue that i read about and that has been known to come off of the pump, anyone know how to check that?
Anybody have any useful insight id really like to know what has been working if anything!! Thank you in Advance.

First check the 12V battery....if it is even the slightest bit weak, replace it....a weak 12v battery causes the hybrid/computer system to go bonkers. Since it doesn't start the vehicle, you will never know until it's completely dead. I recently checked mine and it had 136 CCA from a stated 800CCA.....that's completely shot and would never work in a standard/non-hybrid vehicle.

Second, have someone that knows what they are doing check the auxiliary transmission pump.

Third , and probably the most likely culprit.....check the traction battery.....when they get weak, the vehicle will, jolt, lurch and chug.

unlike a Prius, a hybrid Tahoe will chug along for years on a weak traction battery.


do yourself a favor and find a GM dealer with a hybrid/electric expert technician....this will most likely be a Chevy dealer that sells a lot of hybrids/electric Chevrolets.