TPMS malfunction

[nuQ]

My 2003 M45 has had the low tire pressure light on the dash, and also the info center saying one of the tires is low/flat. All the tires are fully inflated, and the previous owner stated that one of the sending units in a tire was bad.
I took the car to my go-to tire/repair center (Tire Rack recommended) and he said he bought the unit that can read the Infiniti cars ($2000+) and he checked for me. He stated that all four tires were reading that the sending units were fully functional and the batteries were good, and after getting another diagnostic reader and hooking it up under the dash, he said there was some type of issue with receiving unit in the car. The tire units were all good, and the trouble was inside.

I asked if I could bring it back so he could trouble shoot, and fix the issue and he said he could. Are we going down the right path with this repair, and is there something I should have him look at/test first? I'm not sure how many Infiniti vehicles he has dealt with, so I'd like to help get this fixed ASAP. I did do a search here, but could not find an answer other than, I believe, there was a factory recall for bad sending units? I could probably call or email an Infiniti dealer to see if my Vin comes up as being fixed at some point....?

Thanks for the help!

[Q451990]

My wife's G has an issue where the TPMS light comes on after about 20 minutes. I've been told the batteries get low in the sending units and causes this. Is it possible the batteries were functioning when you tested it, but then drop out after a while?

Heath

[nuQ]

Hey Heath! Well, I was told by my tech that the sending units were all firing, and the battery strength was fine in all units. He thinks the issue lies somewhere in cabin where it reads the sending units. He did say he could troubleshoot it, and ultimately fix the problem, though. He has always done right by me and I have no reason to think he would be confident if he really wasn't....but, I'd still like to see if anyone has experienced this and what was done to fix it. Even if it will just help me to help him zero in on the most likely item to troubleshoot first...

[GQM45s]

i have the same issue on my M45 right now, luckily its in warranty but not sure if the TPMS sensor is covered but they had to re register it again it work for a few days then light came back on, I have an appointment set on Tuesday so i'll let you guys know what i find out

[nuQ]

That would be great, thanks. My tech didn't make it seem like it was a big deal...but we'll see.

[GQM45s]

That would be great, thanks. My tech didn't make it seem like it was a big deal...but we'll see.

it doesn't seem like a big deal about malfunction wise, I am all good as long as my tires keep air at a constant pressure haha, the only big deal i have is the annoying light!!! i am pretty anal when it comes to light that turn on when its not suppose to

[nuQ]

I agree about he annoying light,,,,really ANY light that is on in the car that is not supposed to be on! Like yourself, the pressures in each tire is fine, so I have no worries about that, but I do hate to turn the car on and see the info screen displaying a flat, and the constant flat tire symbol being lit near the speedo...

My tire guy is pretty positive he can diagnose and fix the issue, but since it's not any of the sending units, and appears to be a problem with the main reader inside the car, I'm just hoping it's not something only the dealership can rape me over fixing!!

[White-Rush]

i have the same issue on my M45 right now, luckily its in warranty but not sure if the TPMS sensor is covered but they had to re register it again it work for a few days then light came back on, I have an appointment set on Tuesday so i'll let you guys know what i find out

I had the same issue on my M35 before I traded up. All of the tires were properly inflated (per manual gauge) but the sensor /monitor kept giving a false reading. Soo, i took the car in and had it inspected, at which time I found out that my extended warranty had just expired . Anyway, to make a long story short; the sensor was bad / faulty and it was replaced. They gave me a discount on the price & labor, which made me happy, so it was a win win for me.

GL guys and let us know how you come out?

[GQM45s]

I agree about he annoying light,,,,really ANY light that is on in the car that is not supposed to be on! Like yourself, the pressures in each tire is fine, so I have no worries about that, but I do hate to turn the car on and see the info screen displaying a flat, and the constant flat tire symbol being lit near the speedo...

My tire guy is pretty positive he can diagnose and fix the issue, but since it's not any of the sending units, and appears to be a problem with the main reader inside the car, I'm just hoping it's not something only the dealership can rape me over fixing!!

if you can hold it out a bit longer, i'll give you a heads ups when i have the dealer fix it and see if you can get it done without going there - only going since i have extended warranty ( might as well use it when i can)

[finikM35]

How much dealer wants for tpms? im selling my stock rims rigth now and too lazy to take tpms out. Should i do it?

[GQM45s]

car is currently at the stealership today, i took it in late yesterday since i was stuck at work all day. But i'll find out later today and see whats up

[White-Rush]

How much dealer wants for tpms? im selling my stock rims rigth now and too lazy to take tpms out. Should i do it?

If I remember correctly, I think they go from $70 to $85.00 each. I need to order 4 really soon myself, for my wheels.

[GQM45s]

So stealership ended up replacing the TPMS sensor which on my work order costs $117.35 and 73 dollars in labor.. seems to be working fine so far hopefully you can get it fixed cheaper. i was lucky it was under warranty

[White-Rush]

Dang... $117 huh.

Well atleast urs was warranty work.

[SteveTheTech]

That's a great reason to buy a good extended warranty especially with a used car.

As far as a blanket fix for a tpm problem for all Ms...it is just not possible. The weakest point in the system is the battery within the tire monitor. They use a basic coin cell battery soldered in the circuit and sealed with epoxy, (as do almost all TPM systems). They do eventually loose their charge requiring replacement and programming to the system. The Y34 uses a different system that does not communicate well with many after market computers. Everything newer than 07 uses bcm sub-function to monitor tire pressure that communicates better with generic scanners and mostly standard codes.

Best of luck with the repairs folks, that can get expensive fast.

[nuQ]

Ok.....took the M to my independent tech (he has all the correct readers) and again verified that all 4 sending units were functional and the batteries were good, but the problem seems to be coming from the main TPMS unit in the dash. When he hooked up the computer, it showed no communication to the main unit, which he thinks means that the main unit itself is bad, someone unplugged it, or the power source is not functioning...?? Is it possible that the main relay/module for the TPMS can be bad and/or need to be replaced? If so, what am I looking at, repair wise??

I guess my choices are, if it's repairable, get the part/module and have my tech re-stall it, or bite the bullet and head to the dealer?? Thanks

[Wangtang408]

How much dealer wants for tpms? im selling my stock rims rigth now and too lazy to take tpms out. Should i do it?

I had called the stealer before selling my stock rims to see how much they are charging for new TPMS and to compare if it was worth selling vs keeping. You're looking at well over $100 for each (not 4) TPMS not including labor.
I sold my stock rims, went to a quick and fast tire shop (Calderon here in San Jose) charged me $10 per tire and 5$ for valve stems. Total $60. Take out the TPMS and put them on the wheels on your car.

[SteveTheTech]

If so, what am I looking at, repair wise??

Unless you have a list of codes we are just shooting in the dark

There is always a lot of flaming of dealers online, but at the end of the day they are probably the only ones who would be able to give you an answer as to what really is going on.

[Larz]

Not sure how many miles you have driven since this occurance. Usually after a tire rotation, my TPMS are not read by the car until 2-3 days after. However, after my last rotation, it took hundreds of miles and two weeks before I got a reading on my dash. After each rotation, the service guy tested the units and they were transmitting, just not being read by my car. I reckon my car reader is just finiky and will work when it gets good and ready.
BTW - each time I got the readings back on my dash, they worked 100% of the time until the tires were rotated again.

[nuQ]

I wrote to Joe at Scottsdale Infiniti.....the actual module at the dash is the "TPMS Antenna" and is sold for around $81. I think the best bet is going to be taking it to the dealer and have them diagnose before throwing a part at it. As I said, my tech said there was no codes to read, since the unit itself was not showing at all (the onboard TPMS module).

[gbinaz]

had the same issue with my 2003 M45. Replaced the sensors in the rims and the Infiniti dealer could not get the sensors to download to the system in the car. I took it to Wheel Specialists in Tempe, AZ and luckily they had a tech that owns a 2004 M45 and had the same issue when he changed rims. He found a wire at the OBD connector that is not connected to anything and is part of the TPMS system. He took about a 4 inch piece of wire stripped at both ends, plugged one end in to that unplugged wire from the OBD harness and tapped the other exposed wire to the OBD plug in and tapped once, the horn beeped, twice for the next sensor, etc. It worked and for $75 now the pressures read on the dash display and all is well. Sorry I can't describe it better but I'm not a tech and am recalling what he told me. Didn't get the tech's name but am glad he worked out the problem on his own car and I lucked out finding him as the Infiniti dealer had no clue.

[nuQ]

Hmmmm, do you think the unconnected wire was just specific to your vehicle? My tech told me that when he hooked up to the OBD, he could read every other system in the M, but the TPMS was showing nothing,,,as if it wasn't there at all. All tires were registering on his handheld that he took around the vehicle, though.

Joe at Infiniti told me the actual unit that goes bad is the TPMS antenna...It's not as much as I would have thought...but still, I don't want to buy it if I'm not positive that module has gone bad.... Unfortunately I'm having a CEL (check engine light) issue now, after cleaning my throttle body and MAF , too. So a trip to the dealer might be my only option

[gbinaz]

I think the chances of that same disconnected wire being on two separate M45's of the same generation are slim. The system works fine until you need to teach it new data for replacement TPMS's sensors then you need to find and use that extra wire, at least it did for two M45's.