08 Chevy Tahoe Hybrid - problems

Ericntasha5

I have had multiple issues with this vehicle. I have replaced the engine to the tune of $7k. I have replaced spark plugs like theyre going out of style. My latest issue, on a trip home i got service hybrid system on the display, the car shut down, i let it reset, restarted it and it was fine....now it wont start, i have all my lights. can listen to radio, use dvd, heated seats, sun roof...all of it except when i go to start it, nada. I replaced 12v battery without change. The only code it throws is P0AC4.....any ideas? Just want to trade it at this point. Its worth a whopping 4k new engine and all and im done sinking big money into this to be able to drive it for 6 mos and sink more big money into it.

thecardoc3

That is a PCM code that sets when a failure is detected by the Hybrid Powertrain Control Module. You need to go to the hybrid controller and access the codes set there to continue.

Ericntasha5

Is there an easy way to do that? Sorry not a mechanic and i know little to nothing about vehicles. 

kyfdx

Ericntasha5 said:

Is there an easy way to do that? Sorry not a mechanic and i know little to nothing about vehicles. 

No... you need a mechanic

Ericntasha5

Figured as much  

thecardoc3

More precise you need a technician who has studied more and invested in tooling beyond than the average technician in order to be ready to competently address hybrid vehicle, hgh voltage system issues.

Ericntasha5

Yes thata what they said when the deslership i got it from didnt have any hybrid techs and i had to pay to have it towed to one that did. Now it displays the hybrid battery code so thats great

George_49

I have 2008 Tahoe Hybrid. Original owner. It has been the worst car I have ever owned. It is now resting in the driveway. GM dealer I purchased car from would not let me do a test drive. I hoped for the best as l dumped 55K into the local economy. This car had a seal in transmission. Symptoms were:: over 75 MPH on slight incline vehicle pulsed and you could see the RPMs almost a perfect situation to be rocked to sleep. Took it to the dealer 4 times under warranty. Dealer told me : unable to duplicate. Dealer told me that techs can not drive over 65 MPH when test driving. At this point, I took their tech for a ride. Took tech on freeway, going 75 MPH car began to pulse. Tech gets on phone with GM techs. After many calls the GM techs told dealer tech to remove transmission and disassemble it. Next time I saw my car the transmission it was in a hundred pieces. The

George_49

Part 2
I had hoped for a new transmission. GM thought differently. After the transmission surgery I was given back the car. No more pulsing but it started lunging when idling down driveway. It was misfiring and jerking around. Additionally the car , after driving 5 miles to a gate I had to get out of car to open. Jumped back in car put it in Drive and the engine would rev up and no movement of the car. ( Routinely drove to gate almost daily) I would started shifting into different gears and eventually it would move. None of these things could be duplicated by dealer. Once warranty ran out I was stuck with it's problems and I'd decided to repair it myself.
The hybrid tech that had dealt with the car most of its life told me that rebooting the car system was the fix for most issues.
Next there came a time when leaving a stop light. I would step on gas and car would stall. I'd be coasting out into traffic with car totally dead. I would stop car and turn key off and then back on and it would start. I'd put it in manual drive and step on the gas. Once I got moving along I would put it back into automatic drive mode. I've heard and read many stories about the 2008 Tahoe hybrid 2 mode. I would think that the car manufacturer wanted happy customers. I was told that the hybrid technology for GM SUV's was a system developed for buses in Chicago. Buses roll along at low speeds from stop to stop. Sort of like a SUV hybrid stuck in traffic. My car has averaged 17 MPG. I've been afraid to drive this car on vacation. For fear of being stuck somewhere without hybrid service. I read somewhere about a hybrid owner (2008 Tahoe hybrid) that couldn't get any help with the stalling and lunging. They purchased a new transmission control module that was for a newer hybrid Tahoe. Had to change out connectors so it could plug into older style connnector's. 9 pin I believe..last I heard this stopped the stalling and misfiring.
And now the shaking, like the drive line is going to fly out of car. Like a washing machine with an unbalanced load.
Back to transmission control module. Part # the one I got online doesn't work. No part ,# exists. I'm reading about bluebook value 2008 Tahoe $3,000.? I'm hearing GM doesn't make the transmissions and their suppliers aren't getting any new replacements orders.