Cam C.

My 2020 sierra ZRX (AT4 conversion from tuscany) thew service esc up on the dash and all the lights on the instrument panel went out. Also threw a number of other codes.

Well did you ever get it straightened out? Mine threw that code and all the lights and gauges went black as soon as i pulled onto the highway. 2020 GMC ZRX

My 2020 GMC ZRX does the same thing and sometimes it doesn’t wanna shift gears, up or down. Said they couldn’t make the truck do it again and it was shifting fine. Well it’s not by any means. Mostly 4th to 5th or 5th to 6th. I’ve heard it’s the DFM but also heard of similar problems being corrected by replacing the valve body in the transmission. I hope I don’t have to buy another transmission like I have my past 2 trucks. Did they ever resolve the issues with your truck?? Or any of y’all’s trucks?? If so, what did they do?

I have no idea honestly I was just seeing if anyone else had experienced similar issues before

It’s a 2020 ZRX by Tuscony. Everyone thinks I got the name wrong so don’t feel bad. There are only a handful of them being made every year. They start as an AT4 then Tuscany turns them into a ZRX at their factory.

It’s a 2020 ZRX (made by Tuscany). Idk how it had 2023 I guess I typed it wrong because I have a 2023 AT4 also.

None.

Mine ((2020) GMC ZRX)did something similar but all my lights and gages stopped working 3 times on my way home. The last time they came back on they stayed on and haven’t done it again. Also truck shifts weird sometimes and wayyyyy too early. Sometimes you gotta make it shift. Also the rpm’s fluctuate while driving and when I’m stopped. When I accelerate I can hear a tick coming from the motor like a misfire or something but it doesn’t do it all the time. Out of time on warranty and didn’t get an extended one.

2020 GMC ZRX (Supped up AT4) RPM’s fluctuate up and down almost making the sound of a 6.2 with a cam in it. The RPM’s drop significantly almost causing it to stall sometimes when doing the following; idling, coming to a stop, when you press the accelerator attempting to make it downshift, and when going up a hill. Also it tries to stall sometimes even with no change in throttle, terrain, or speed as if it’s taking the pedal away from you. Gas mileage and power decreased significantly since this first occurred. Forward gears 3-5 stick when you get in it a little going up a hill (only happens on a hill) and I have to let off the gas and ease back into it to get it to shift. No problems or misfires whatsoever when starting and it has never actually stalled out all the way. Also, now when I come to a stop I can hear it down shifting and running through the gears. It runs perfect when I get into it and the rpm’s are high, but when they are low is when the problems occur. I can also hear a little tick like a misfire every once in a while when accelerating. Not throwing any codes or check engine light. I’m thinking something with fuel management/distribution, combustion, air leak, or something simple