2012 LT Model adding Cruise Control

[frobate]

I know....I'm sorry ....yes I am starting another thread on this same subject. However, I think I may have some additional information and I think Ms. Danny Stone was on the right path but never saw it to completion due to the purchase of an RS model. If I add this to the existing thread it will be lost on page 28 or 29 and may not ever help anyone.

In pouring through the 28 or so pages of the other thread, there seemed to be only two people who actually got to the point of putting steering mounted controls on and taking the car to have the BCM flashed. The flash didn't work and was performed in late 2012 or so. In my opinion, neither of these people installed the right combination of components. I feel the right combination is new wheel (with switches and harness installed) and a new clock spring. Or new switches, wiring harness and new clock spring. The clock spring, with additional circuits for the added switches is a necessity!!!

So, my car is at the dealer as I am writing this, I will know by the end of the day.

Thanks for a great page and an incredible amount of information about this awesome little car.

 

[laborsmith]

It will be interesting to learn if this works. All through the referenced thread I had often thought: it's the clock spring people! Well not all through, but once Ms.Danny brought it up.


Laborsmith

 

[frobate]

Just got a couple calls from the dealer...they are saying that the BCM and PCM have both been changed to accept cruise but the switches are not "talking" to the control unit.

They are still messing with it...crap... not a lot of hope...doesn't make sense

 

[ScarabEpic22]

Shouldnt have to change ECM or BCM, just flash it with a VIN from a cruise-equipped vehicle.

Yes, start with the proper clock spring, switches for a Sonic, proper harness, and flash the BCM with the cruise RPO-equipped VIN.

 

[qwed94]

better be real careful if you are going to flash it with any VIN # that is not "that cars proper VIN"

Some states have different methods of "emission testing". I know in MO. You will go thru lots of red tape to get your car to "legally" pass inspections, if the VINs on the computer and actual car do not match.

 

[laborsmith]

Using a cc equipped vehicle vin should not change the vin. We know several members have used RS vins to flash their non RS Sonic to get the RS steering algorithm without incident and I do not see a difference.


Laborsmith

 

[Ms.DannyStone]

I got all my parts directly from GM. They said with the new wire harness and clock spring and steering wheel it can be flashed. But never got the chance to do it.

 

[frobate]

Danny, do you have part numbers of those pieces?

Do you remember was the harness in the wheel or on the steering column??

 

[frobate]

Ok, dealer says they programmed "everything they could" to make the cruise work. But it isn't getting the signal from the switches.

I printed out the schematics from ALLDATA and checked the switch operation at the wheel.

Both the Radio function and Cruise function switches throw a resistance between the sense circuit and 12 volt (+). I have 12 volts at the switches and the lighting works on the switches. This proves that the "extra circuits" in the clock spring are attached and functioning. Well, at least power and lighting which was not part of the original clock spring.

So, on to the resistor and switch functions. The cruise switches measured correctly but in the wrong order according to the ALLDATA schematic, the radio control switches measured correctly.

My next step is to trace it back to the BCM to assure that everything is connected.

According to the dealer "everything is turned on"...may or may not be true.

 

[frobate]

Using a cc equipped vehicle vin should not change the vin. We know several members have used RS vins to flash their non RS Sonic to get the RS steering algorithm without incident and I do not see a difference.


Laborsmith

Did the dealer do the flash?? I don't get the feeling like this one would do that.

 

[laborsmith]

My RS VIN was used by several members but the difficulty for them was finding a dealer willing to do it.

Dealers who move a lot of Camaro or Corvette vehicles reportedly were more willing. Cost to do the steering algorithm flash was around $50.


Laborsmith

 

[XilliK]

Not sure if this question goes here... but sometimes when I'm driving and usually only notice when I'm using cruise control, but if i say put my blinker on or flash my brights it seems the car loses power, the rpms start to lower almost as if it wants to turn off? I've had similar problems in my zx2 but it was when i was slowing down then it would turn off on me... any clues as to what might be going on here?

 

[laborsmith]

Any aftermarket add on that use electricity? It could be the small output alternator.

Laborsmith