[Whatwarranty]

We lowered my fathers car yesterday and found out you have to have the mrc relearned. Took it to dealer and they state they can’t do the relearn because the cats are off the car..... that makes zero sense to me. Any input on this or how it can be done? I see nothing in hptuners so i guess it has its own controller.

[crosive]

the controller is in the trunk. Under the bose amp if you have that.

It doesn't make sense for them to not want to reprogram it because your cats are gone. I can understand charging to reprogram, but simply refusing doesn't make sense

[51FIFFT]

Never heard of this, I'm lowered with MRC and all seems normal.

[Atomic Ed]

The MRC system is set up so that at normal, static ride height, the sensors are set at a zero voltage reference point. With lowering, you've changed the static height and now have a negative (?) voltage at rest.

While in theory the BCM needs a calibration, the actual difference is nominal in ride quality and the ability of the MRC to work. I wouldn't worry about it.

And BTW, your dealer can't actually change the programing in the BCM to account for ride height differences. The flash for the BCM comes from Chevrolet only and is matched to your VIN number.

[MGD]

I had mine lowered 2 years ago and did not do anything to the MRC. Runs just fine with the sensors as they are. What happened if you put 150 lbs in your trunk? It lowers the ride height also, do you have to drive by the dealer to get it programmed?

[Soleil]

Originally Posted by Whatwarranty

We lowered my fathers car yesterday and found out you have to have the mrc relearned. Took it to dealer and they state they can’t do the relearn because the cats are off the car..... that makes zero sense to me. Any input on this or how it can be done? I see nothing in hptuners so i guess it has its own controller.

I never heard about that. You adjust the suspension/wheel alignment but that’s about it.

[nicktechla]

Originally Posted by Atomic Ed

The MRC system is set up so that at normal, static ride height, the sensors are set at a zero voltage reference point. With lowering, you've changed the static height and now have a negative (?) voltage at rest.

While in theory the BCM needs a calibration, the actual difference is nominal in ride quality and the ability of the MRC to work. I wouldn't worry about it.

And BTW, your dealer can't actually change the programing in the BCM to account for ride height differences. The flash for the BCM comes from Chevrolet only and is matched to your VIN number.

I didn't think there were any ride height sensors?

[Laststandard]

Originally Posted by nicktechla

I didn't think there were any ride height sensors?

If you have mag ride, there's a sensor at each wheel that tells the controller where the suspension is in it's travel.

[Soleil]

+1
In the pic left side of the yellow spring. That little tiny arm.

[nicktechla]

Originally Posted by Laststandard

If you have mag ride, there's a sensor at each wheel that tells the controller where the suspension is in it's travel.

I thought the sensor just read impact to determine how much dampening to apply

[Tr6]

No need to bother with MRC calibration plus there is no calibration. Only 1 calibration that was flashed on the car at the factory which is the only one dealer can flash back. Vettes did get a new MRC calibration, maybe we will too... Who knows. Plus from the sounds of it, that dealership also sells blinker fluid? Since they can't reflash MRC calibration because you don't have cats?

[Whatwarranty]

Car would act like you were on ice when going full throttle ass all over the place. We found another dealership to do it 125 bucks and runs perfectly. I personally drove the car and it would not stay in 1 lane while accelerating with 100% traction. They did their thing and all is well I’d say took them 30 minutes.

[Soleil]

What did the dealer do????

[51FIFFT]

I lowered mine and only did aliment. No issues up to 150 mph or at the track under 100% acceleration. I wonder what they did? who lowered it? My car drives the same other than its lower now.