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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    I'm not sure but I'll check this weekend. Thank you for the heads up though.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    well, the saga continues. We believe there is a short or break in one of the wire looms between certain modules and not so much a bad module. Our Ohms seem to confirm the modules are unable to talk to each other. Will continue to update the thread.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    mechanic and I drove for over an hour with the scanner plugged into the OBD and no limp mode or dash lights. Drove it to work today with scanner plugged in with no issues. Unplugged scanner and did a 20 minute delivery and it went into limp mode again with new dash lights this time. Here is what...
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    I had my mechanic disconnect and reconnect the 16 wire connection to the transmission, checked all the grounds and yes the battery terminals are super tight. The hybrid battery checked out good at 313 volts. I ordered an OEM throttle pedal this morning.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    I put it into M4 this morning and did a 30 minute drive and the truck went into reduced engine power mode again. Lost all gears and pulled to the curb. Turned engine off and back on again and was able to return home no problem. Same codes same issues. UGH.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    never mind, I figured out what M4 mode is.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    How do I get it into M4 mode?
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    good morning and thank you for the response. I cleaned the throttle body already but I'll look at the throttle pedal too.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    I"m just now getting an update to post. When I went to pick up the Tahoe at the dealership and drove it home it went into limp mode again. I pulled the truck off to the side of the road, turned the engine off and started it backup and limp mode was gone but the check engine light was still on. I...
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    I'm in possession of the truck and it's driving great and it's not gone into limp mode yet..... they did clear all the codes so hopefully that will make a difference. If the problem persists then I will try to find another shop that has the software to dig deeper into my issues. What I'll do...
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    yep, they took it for a test drive and couldn't duplicate my issues and parked it and told me to come get it.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    ugh. Ok, thank you. I'll keep trying to figure this out. I'm super bummed the dealership wasn't much help. He actually told me they don't really work on vehicles over 10 years old either. What a racket.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    so, the truck has been sitting at the dealership for 10 days and they can't get the truck to duplicate any of my issues. Weird that with all the codes that they pulled up they can't do a little bit of diagnosing but they called and asked me to come pick it up. I asked if they can restore the...
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    thank you for your detailed response. Would the fact that I go into limp mode and lose all gears forward and reverse point to the transmission control module as being my problem? I can't afford not to fix this as I have a buyer for this truck and I need the funds. Caught between a rock and hard...
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    just an update, it's going to the dealership on Wednesday as my local shop doesn't have the proper software tools to clear the main code which is the P0ac4 code, also it being the Hybrid model he didn't want to touch the truck to be honest. Will see what the dealer thinks.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    Ok. You're probably right. I'm dropping off the truck tomorrow at my local shop. I'll post back with an update.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    ok, the problem is in order to get home after the truck went into that limp home mode I had to disconnect the battery to get out of the lane of traffic and get home. by then I had zero codes for him to check. he did put in live data mode but everything checked out ok. bizarre.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    just an update, my mechanic couldn't diagnose the problem(s) so I'm taking it to the local shop that I trust. I cleaned the throttle body which didn't really do much. I thought about replacing it but do not want to throw parts at it without knowing it's the problem. I'll keep this post updated...
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    ok, I do not have any aftermarket equipment tied to the OBD. I'll look into the fan idea, thank you.
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    thank you for the welcome!
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    2012 TAHOE HYBRID CODES P0AC4, U186A, U186B

    Good morning forum members, I've not found much info on my condition but here's the short of it. Back in March I was going about 75mph on the Garden State Parkway when I got the traction control and reduced engine mode dash warning lights/errors when it all just shut down on me in the far left...

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