Acura MDX SUV Forums banner

1 - 19 of 19 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter · #1 ·
So, I scratched on the curb and the valve stem broke off - loosing tire pressure. Now i put on a spare and get the TPMS error - expected. However, I drove over a few miles back home and then a bunch of errors pop up ABS, Brake System, Lane Mitigation, parking brake - et all.
But the fun does not end here, the hatch does not open!!! Now I absoutely dont know what to do at all !

Any ideas ?
 

·
Super Moderator
Joined
·
1,968 Posts
Since 22 model is so new, not sure anyone has correct answer. Why not take it to dealer for investigation and report back what dealer said? ;)
 

·
Registered
Joined
·
403 Posts
117433


If I were to guess at what caused the warning lights, I'd say the spare tire has a slightly different diameter than the other three tires. Because of the difference in diameter, the spare rotates slightly faster or slower than the rest of the wheels. The ABS system probably detected a variance in wheel speed that is not "normal" and has triggered a warning light to let the driver know something is wrong. A problem with the brake system could subsequently trigger warnings/disable the other safety systems to prevent them from activating.
I haven't a clue how any of that would cause the hatch to stop working.
I predict a dealer visit is in your future.
 

·
Registered
Joined
·
29 Posts
So, I scratched on the curb and the valve stem broke off - loosing tire pressure. Now i put on a spare and get the TPMS error - expected. However, I drove over a few miles back home and then a bunch of errors pop up ABS, Brake System, Lane Mitigation, parking brake - et all.
But the fun does not end here, the hatch does not open!!! Now I absoutely dont know what to do at all !

Any ideas ?
This is with the stock spare tire?
 

·
Registered
Joined
·
3,286 Posts
Is you donut on the front or rear? It is better to flip/flop and put a donut on the rear since the front carries the most weight, the MDX is fwd bias, does all the turning, and majority of the braking. The sh-awd system is sensitive to wheel size and tread %. For down the road: It is recommended to change out both tires on the same axle with sh-awd if you get one non-repairable flat on a tire. This is assuming the other tires are around +/-50% -60% of tread life left.

I had the same error messages on my 18 RLX when I had to run the donut spare on the front waiting on replacement tire after a pothole. I didn't need to drive the RLX and just waited until the replace tire came in. I've since invested in a full-size spare to keep from getting those error messages the next time I need to wait +10 days for a replacement.
 

·
Registered
Joined
·
29 Posts
I had the same error messages on my 18 RLX when I had to run the donut spare on the front waiting on replacement tire after a pothole. I didn't need to drive the RLX and just waited until the replace tire came in. I've since invested in a full-size spare to keep from getting those error messages the next time I need to wait +10 days for a replacement.
That's crazy that the donut isn't the right diameter to prevent messages.
It almost serves no purpose then. Flat tire? can't drive? Put on this spare! Oops, still can't drive! Oh well.......

I also want to get a full size spare - it's nice to not have the speed/mileage limitations of the donut.
 

·
Registered
Joined
·
3,340 Posts
That's crazy that the donut isn't the right diameter to prevent messages.
It almost serves no purpose then. Flat tire? can't drive? Put on this spare! Oops, still can't drive!
While I agree with you that using the donut spare shouldn't by design cause any of these messages, to be fair, it serves it's only purpose - to allow one to still drive the vehicle at least to get to a point where the flat can be repaired. There's no reason to not drive despite some warning messages popping.

I have the donut spare on mine and haven't used it yet in the 8 years I've had my 2014 MDX. I still want it and chalk some of that up to luck and making sure my tires are decent. I've had flats in other vehicles that were unavoidable and where a fix-a-flat can wouldn't be of any use hence the luck.

A full size spare is even better.

Reminder to anyone reading this - more than a few people have been stuck after they go to use the donut (or even full size) spare only to discover it's very low on air because they've never checked it or topped it up. Make sure you periodically check the air pressure in the spare and top up as need be. Better yet is to also have a portable air compressor in the back to top up if need be in an emergency.
 

·
Registered
2018 Acura MDX SH-AWD Tech
Joined
·
62 Posts
Sounds like that rim will have a case of curb rash. As stated, the warning lights are due to the smaller diameter spare.

As to the rear gate not opening, have you tried the fob and cockpit buttons? Or is it just the toe kick that won’t work? If it’s only the toe kick, that system is right by the spare tire’s home, so maybe it got bumped?
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #9 ·
The car is operational finally…. and yes the donut spare disables everything! Driving the car on the spare donut is impossible…. At most you can only manage 10-20 miles!
the hatch is another big issue…. I hear from the service manager that it maybe an issue with some pressure sensor… I don’t understand what It is though and where this sensor is. I am absolutely going to hunt for a full size spare!

@jefferson88: thank you for the Manual hatch operation guide… it saved me a lot of additional trouble.
 

·
Registered
Joined
·
3,286 Posts
I added the Ryobi P737 ($34, Amazon, no battery) I used for adjusting my PSI on my fat tire MTB and vehicles. I already had Ryobi batteries from other tools. I sometimes toss the air pump in the back of my vehicle on road trips because it is so small and can pump up any size tire (including my spare to 60 PSI). I still kept my OEM/fix-a-flat air pump in my MDX when I upgraded to a full size spare in my 19 MDX. I didn't add TPMS to my full size spare and I set my PSI to 45 on the full size spare so I only need to check it 1-2 times a year.
 
  • Like
Reactions: Maverick02

·
Registered
Joined
·
29 Posts
I looked at the 2022 mdx manual.
The two normal tires are:
tire: 255/55R19 107H 30" diameter 5.5" sidewall for 19" wheel
255/50R20 105H 30" diameter - 5" sidewall for 20" wheel

The spare tire is:
T155/85D18 115M - 28.374 inch diameter.

So that answers that.
Flipping through the goodyear site, they don't seem to have a compact spare tire that has a 30 inch diameter.
They should, at the very least, write in the manual that you will get all of these errors - perhaps even something
that pops up if TPMS is not detected, asking if this is a spare tire.
 

·
Registered
Joined
·
29 Posts
Another question: Do you know how fast you were going with the spare tire when the warnings occurred?
The manual has a warning to stay below 50 MPH when using the spare.
 

·
Registered
Joined
·
3,286 Posts
I stuck to the side streets with speed limits of 35-45 mph when I had to drive the RLX. I "might" have gone +50 mph without realizing it (easy to do with 377hp/341tq). I don't know if it was going to happen eventually after X miles at Y speed OR me just bumping past the 50 mph donut limit? The warning lights didn't go away after that until I put the regular size tire back on about a week later.
 

·
Registered
Joined
·
29 Posts
So I've been doing reading, and apparently it is fairly common for a compact spare to have a smaller radius than the original tires. News to me.
The thinking is apparently that since the tire width/tire tread quality/etc is different than your other tires, you need to be conservative with your driving anyway.

I have to suspect that these warnings will only come up if you exceed the 50mph as noted in the manual. But on a sporty car where it's easy to exceed that.....
I think there should be something to avoid people shooting themselves in the foot. Especially for "spare tire noobs" like me.

LIke a big sticker on the spare tire that says, "SET SPARE TIRE MODE if you use this tire!" and spare tire mode sets a speed limiter of 50 mph.
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #15 ·
I did not exceed 40 mph… cause it was anyways city streets where most of the roads anyways are 35mph limits. They came on once I drove and stopped and then started the car again!
 

·
Registered
Joined
·
3,340 Posts
I have to suspect that these warnings will only come up if you exceed the 50mph as noted in the manual. But on a sporty car where it's easy to exceed that.....
And it's really not very safe driving no more than 50mph on a freeway and there's often no alternative than to drive on a freeway. If I was to get a flat on some of my big trips while in the western part of the country it could be a long ways to the next town that has tires for sale. When equipping a vehicle with some kind of spare the manufacturer should equip it with a tire that can at least handle reasonable and safe speeds. A full size spare will do it or worst case, a compact spare that's better matched and constructed to handle normal speeds - and if there are none available then they should just specify and provide a full size spare.
 

·
Registered
Joined
·
372 Posts
yup, look CAREFULLY at the spec's when using a donut spare. In general, no more than about 50mph, no more than 50 miles or so total distance on the tire. The run flat's also have a similar set of restrictions.

that's why I always have gone to a full sized spare. We often travel where (a) there is NO cell service for 50 miles or more and (b) nearest town is 100 miles or more away and (c) nearest town that might have a tire shop with a suitable tire is 200 miles or more away. NOT a time to depend on (a) donut spare or (b) hokey tire inflator system or even (c) run flat tire.

Yes, it has been a long time since we had a tire problem, but in any of the conditions above a flat tire could end up easily wasting a day or more to get back on the road.
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #18 ·
Well… having experienced the situation even though it happened close to home… I am in the market for a full size spare
 

·
Registered
Joined
·
2 Posts
So, I scratched on the curb and the valve stem broke off - loosing tire pressure. Now i put on a spare and get the TPMS error - expected. However, I drove over a few miles back home and then a bunch of errors pop up ABS, Brake System, Lane Mitigation, parking brake - et all.
But the fun does not end here, the hatch does not open!!! Now I absoutely dont know what to do at all !

Any ideas ?
Had a similar with my wife’s Lexus RX350. Scary driving It with the donut, went straight to discount tire and bought a regular size spare.
 
1 - 19 of 19 Posts
Top