Acura MDX SUV Forums banner
1 - 12 of 12 Posts

·
Registered
2004 MDX, 2022 MDX
Joined
·
4,300 Posts
Discussion Starter · #1 ·
Summary: The original TPMS sensors in a 2004-2006 MDX will probably need replacing soon. You can use aftermarket TPMS sensors to save a bundle of money, but you may need to clear the codes in the TPMS computer.

Background: The Tire Pressure Monitoring System (TPMS) became standard equipment on all MDXs beginning with the 2004 model year. TPMS operates based on signals provided by TPMS sensors mounted inside each of the four tires. Inside each TPMS sensor is a non-replaceable battery which powers that signal.

The original part number for the TPMS sensor for a 2004-2006 MDX was 06421-S3V-A00, which had a list price around $30 each. This part has been discontinued, and has been superseded by the replacement part number 06421-S3V-A04, which has a list price around $100 each. :mad:

So here's my story. I have a 2004 MDX. Last fall, the TPMS warning light on the dash - the one that says TPMS - came on, and was on most of the time. At that time, I was using my original wheels with their original, twelve-year-old TPMS sensors. I knew about the non-replaceable batteries in them, so I assumed that the warning light was probably caused by the failure of those batteries. At the start of winter, I swapped to my winter tires, which were mounted on wheels along with TPMS sensors that I bought in September 2011, and the TPMS warning light went out, thereby confirming my assumption that the original sensors needed replacing. Later on in winter, I switched back to my original wheels and TPMS sensors, and the TPMS light once again appeared. Because the original part number TPMS sensors are no longer available and I didn't want to pay triple the price for the replacement ones :mad: I bought aftermarket replacement sensors. The ones I bought are made by Dorman, their part number 974-037. I bought a set of four from Direct Auto for $98 with free shipping. (A quick check on Autozone's website shows sensors made by Schrader, VDO, and Wells, at prices from $45 to $60 each.)

When my (independent) mechanic installed the new aftermarket TPMS sensors on the car, he mentioned that the TPMS warning light was still on, and asked me if there was a learning cycle for it. I knew that there was, that you need to take a short drive when changing the TPMS sensors, and then the warning light should go out. (The spec in the service manual says you need to drive at least 15 mph for at least 40 seconds.) So I told him not to worry about the warning light, and I picked up the car.

However, the TPMS warning light did not go out, even after driving 40+ miles on it. Although now it was slightly different; when starting out, it would show the other TPMS warning light (the little icon that looks like the cross-section of a tire, with an exclamation point in the middle) for a few miles, then switch to the warning light that has the word TPMS.

I contacted Dorman technical support using the chat function on their website, to ask them if they had any advice. They said it was possible that their TPMS sensors were asleep (their terminology), and that I should try removing the valve cores from the valve stem part of the TPMS sensors for 3-5 seconds and then re-inflate, that the sudden drop in pressure might wake up the TPMS sensors. I tried this, but the warning lights were still on after doing so.

At this point I was guessing that the aftermarket TPMS sensors wouldn't work, and I would need to buy Acura branded ones at the dealer. Fortunately, this guess turned out to be wrong. I took my car to the Acura dealer and explained the situation to them, asking them to do whatever diagnostics they could using the aftermarket sensors (without spending too much time going down that road) and then replace them if necessary. They found that the TPMS computer had set a whole bunch of error codes. They cleared the codes and tried taking it for a short drive, without changing the TPMS sensors yet. Lo and behold, the TPMS warning light did not come back on, and has not come on since then. Problem solved! So I only had to pay a nominal diagnostic charge, and did not have to buy Acura-branded sensors for several hundred dollars.

With the benefit of hindsight, I erred in telling my independent mechanic who installed the sensors not to worry about the warning light, and should have instead told him to clear the codes. But now I know that, and I'll tell him that six years from now when we have to replace the TPMS sensors in my winter wheels, which will then be twelve years old and need replacing. :D

I hope retelling this story benefits other owners who are not sure what to do when the batteries in their original TPMS sensors wear out. Inexpensive aftermarket ones appear to work fine... but you may need to clear the codes in the TPMS computer to make the dash warning light go out.
 

·
Registered
Joined
·
270 Posts
I've got a set of Schraders in my glove box just waiting for the tires to go. (They are almost there)
Cost me $25 each but that was luck.

That's what my two different tire guys here use so hopefully it's good.

Did you get those TPMS from Ebay or something? They might be too old and/or going defective.
 

·
Registered
Joined
·
278 Posts
I just ignore the tpms light and check my tires once every 2 weeks or so using a small air pump from slime. I just set to 32 psi and let it add as needed. 5 minutes is all it takes
 

·
Registered
2004 MDX, 2022 MDX
Joined
·
4,300 Posts
Discussion Starter · #4 ·
Did you get those TPMS from Ebay or something? They might be too old and/or going defective.
Maybe you didn't read the whole post. The new aftermarket TPMS sensors are working fine. The problem was due to not clearing out the TPMS error codes after they were triggered by the original, 12-13 year old TPMS sensors whose batteries had run down.

The sensors I bought were new and AFAIK not very old. Direct Auto sells them for the same $98 with free shipping on their own website as well as on eBay. They sell a ****load of them - 259 sets sold on their current eBay listing - so their stock ought to be refreshed regularly and not getting old.

I just ignore the tpms light and check my tires once every 2 weeks or so using a small air pump from slime. I just set to 32 psi and let it add as needed. 5 minutes is all it takes
I check my tires regularly (and add air as needed). However, it's nice to have TPMS working. All you need is to have TPMS alert you once that you have a leak - yes, it's happened to me, even checking them regularly, a leak can come on quickly - and it's absolutely worth spending the hundred bucks to get the sensors replaced. (There's no extra charge for labor if you have them replaced at the same time as you're replacing the tires, as forbin and I both did.) Also, it's very distracting to have a warning light on all the time, and reduces the ability to immediately notice any other warning light that goes on. It's SO worth it, I would not want to leave the TPMS warning light on all the time on my car. With your car, though, that's your decision.
 

·
Registered
Joined
·
34 Posts
Schraders cost a lot more than Dorman, but on Amazon the reviews are like night and day in favor of Schrader when comparing the two brands for 1st gen MDX.
 

·
Read Only
Joined
·
272 Posts
"They found that the TPMS computer had set a whole bunch of error codes. They cleared the codes..."
How did they do this and how can I do this at home? I want to try this before buying new sensors. About 7 years ago I was told a sensor was bad, replaced that sensor and nothing changed. The tpms light usually stays on. I'd like to correct the issue instead of simply ignoring it.
 

·
Registered
Joined
·
270 Posts
"They found the TPMS computer has set a bunch of codes" Huh? The TPMS computer has 5 total codes....tire is low (4 lights), and TPMS can't be found (the TPMS light).

As TPMS batteries last 10 years, I suspect you had more than 1 tire go bad. You fixed one, but not all.
 

·
Read Only
Joined
·
272 Posts
The quote is from the original post.
My MDX was about 6 years at the time my issue began and when I was told I had one bad sensor.
 

·
Registered
Joined
·
430 Posts
"They found the TPMS computer has set a bunch of codes" Huh? The TPMS computer has 5 total codes....tire is low (4 lights), and TPMS can't be found (the TPMS light).

As TPMS batteries last 10 years, I suspect you had more than 1 tire go bad. You fixed one, but not all.
No...that's the number of warning lights that can be activated on the dash. The actual number of DTCs that the computer can store is 28 (that's what the chart in my Acura Service Manual shows).

Also, did you even read his post? He replaced all the sensors, so how do you figure he 'fixed one, but not all'?
 

·
Registered
Joined
·
270 Posts
No...that's the number of warning lights that can be activated on the dash. The actual number of DTCs that the computer can store is 28 (that's what the chart in my Acura Service Manual shows).

Also, did you even read his post? He replaced all the sensors, so how do you figure he 'fixed one, but not all'?
Walt92 whom I was responding to, only changed 1.
 
1 - 12 of 12 Posts
Top