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Discussion Starter · #1 ·
I've had my '14 Adv since last September. In October of last year, I changed out the wheels/tires from stock, going from 19" to 17". I did this for a number of reasons including looks, range of tire choices, and desire to have a little more sidewall to deflect the crappy Boston-area roads.

Starting in December or January--can't remember--I started getting an ACC malfunction. The system would shut down, often followed by LKAS, and CMBS, but these systems would show malfunction ONLY after the ACC malfunctioned. On some occasions, only the ACC would shut off. This would predominantly happen when the outside weather was below 30 degrees, leading me to believe there may be a fault in a wiring harness somewhere, but now that the weather's warmed up, I'm noticing the faults in warmer weather as well. There seems to be no correlation between distance driven, driving style, weather, etc...at this point, it feels somewhat random.

After a trip to the dealer, they suggested it was because of the different size wheels tires, but they weren't certain. Below is the tire size comparison between stock and what I'm running, and there is only a 0.3% difference between the two. I find it hard to believe that Honda/Acura would design a sensor system with such tight parameters that such a small discrepancy would throw off the entire system, but I've been wrong before...what do y'all think?

Size 1 (Stock): 245/55 R19
Size 2 (Current): 245/65 R17

Diameter
Size 1: 29.6"
Size 2: 29.5"
Diff: -0.3%

Width
Size 1: 9.6"
Size 2: 9.5"
Diff: 0%

Sidewall
Size 1: 5.3"
Size 2: 6.3"
Diff: +18.9%

Circum.
Size 1: 93"
Size 2: 92.8"
Diff: -0.3%

Revs/Mile
Size 1: 702
Size 2: 704
Diff: +2
 

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Acura will keep on blaming the 17" tires until your warranty expires. Do you still have the 19" in your garage to swap out to test?
 

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It's generally only the overall diameter/radius of the tires and the relative differences between the mounted tires (ex: two different size tires mounted at the same time or a very worn tire plus a brand new tire) that could have an effect on systems. Nothing in the vehicle doesn't actually know or have a way to know the actual rim diameter or specific tire size. The diameters for the two sizes you mentioned are almost the same - there'd be more of a difference than that just between unevenly worn tires of the same size.

You probably have something else going on. The idea above of putting the originals back on before taking it back in to have this looked at is a good idea. Alternatively you could just prove to them that the tire diameters are effectively the same between the sizes and see if you can find a tech who can think past the first excuse to reject looking at this.
 

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Discussion Starter · #5 ·
It's generally only the overall diameter/radius of the tires and the relative differences between the mounted tires (ex: two different size tires mounted at the same time or a very worn tire plus a brand new tire) that could have an effect on systems. Nothing in the vehicle doesn't actually know or have a way to know the actual rim diameter or specific tire size. The diameters for the two sizes you mentioned are almost the same - there'd be more of a difference than that just between unevenly worn tires of the same size.
Yeah, this is what I was thinking...but to the point above re: warranty, the burden of proof is in my court.

That said, I unfortunately don't have the original wheels/tires to test the theory. I wonder if the dealer would allow me to borrow a set, or ask them to mount another set for testing purposes...
 
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