FatsWaller

I got this message back in June and the DIC showed that the Left Rear sensor was not broadcasting ('xxx' in place of tire pressure). When I restarted the car after stopping, the message was gone, and didn't come back until about 3 weeks ago. Same sensor, and once again OK after restart. However, after reading numerous posts on this, it seemed that the most likely culprit was the sensor battery, since the car is now 8 years old. I changed out all 4 sensors with new AC/Delco sensors (bought them on Amazon) last Thursday. The date code on the sensors was about 6 months, so the batteries should be fine. They are the correct part #, and were tested before they were installed. Then, went on a club tour yesterday, and the message reappeared after about 1/2 hour or so driving to the event start. In this case, it went away once after a restart, but came back on again soon after, and stayed on regardless of the number of restarts. Same LR sensor. Unless I'm really unlucky, and the one of four new sensors was bad just happened to go in the LR wheel, it's too much of a coincidence. However, when I went to a local car show yesterday evening, no message and the sensor was OK.

Today, I drove to a car show, about 1 hour away, and everything is still OK. So after further reading, here are my thoughts:

The problem always occurred when I was using a model 2595LM Garmin, and never happened when I wasn't. It's a 2595LM. I didn't happen in the 6600 mile road trip, using a different model Garmin. Interference from a Garmin has been suggested on this forum as a possible cause of the problem. Other posts suggest that if you are driving close to other Corvettes, that may confuse the system, and of course there were around 30 C6s near me yesterday. This seems a stretch, but you never know.

I'd sure welcome some expert advice on what I should do next, because I don't like the uncertainty of having a sensor that doesn't work at random. I guess I could get a different Garmin and see what happens - that might be the cheapest solution.

HOXXOH

When the RCDLR pings the sensors, the LR is the last one in the sequence. If you get any interference during the time the sequence starts and ends, the LR will not read. The interference can come from lots of different sources, including older cars (pre-electronics) and especially early Vettes that don't have all the RF shielding in place. Since the sensors are serialized, when your car is initialized to match the location with the RCDLR, it identifies the serial number. You can't receive a signal from any other sensor than the one the RCDLR has asked to respond.
If you continue to have a concern, reprogram the car in the reverse order.(LR-RR-RF-LF). The DIC will read the rears as fronts and vice versa. If you have an interference problem, the DIC will still show XXX in the LR, which is really the LF, but you know that sensor is good.
BTW, I've had the interference issues for about the last 60K miles. The DIC has reported all sorts of false messages at the LR. It has always reset itself after a maximum of 3 ignition cycles.

FatsWaller

Thanks - I do have a TPMS activation tool, so the idea of reprogramming the order in the reverse direction is a great suggestion. I'll try this tomorrow and see what happens.

FatsWaller

Just an update: My el-cheapo not made in North America TPMS reset tool decided to do one wheel (LR), and then not do any more. End result - one wheel is programmed, the others are in limbo. The local GM dealer attempted to help me out, but their el-cheapo not made in North America reset tool decided to do 2 wheels, and then stop (LF and RF). Now, only 2 wheels are in limbo. So, they are getting a proper GM tool from their other location for tomorrow. It's not supposed to be this complicated, is it?

HOXXOH

Discount tire does it for free and has never failed me yet.

torquetube

I think it's unlikely that two reset tools and two pressure senders were bad. The common denominator is your Corvette, so I would suspect the RDCLR radio/antenna or a source of interference in the car or on your person.

FatsWaller

All the sensors were replaced with new units, so yes, unlikely two are bad. The problem existed with the original 'green' sensors, and now with the new 'black' sensors. I was about to say that there is nothing electronic in the vette right now and when the programming attempts took place other than original equipment, but there is actually an EZ-Pass transponder. I'll pull that out first thing tomorrow, but the problem had happened once before without it being there. I don't know how they programmed the new sensors a few days ago, but they did work fine for a while. I wasn't in the car or that near the car when the service adviser tried his luck at it today, although I did have a cell phone in my pocket. I guess that leaves the RCDLR as a possibility, as well as the cell phone and transponder. I'll try programming again tomorrow without the phone and transponder.

Mordeth

I have 4 sets of wheels/tires and am constantly changing them as my car is raced and I go through a set of tires in a weekend.

When you are programming each sensor using the tool, you need to be patient and ensure the tool is placed on the correct spot on the tire. It is finicky. I have luck placing the tool end directly on the side wall of the tire right above the valve stem (where the TPMS sensor is internally located). Sometimes I have to hold it there for 5-10 seconds before I hear a honk. Other times it honks right away. And even other times I have to move the tool around slowly on the tire until the car honks.

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GMJim

It's unlikely your Garmin would cause an issue as it doesn't transmit anything. It only receives. I would bet that because your'e sitting directly in front of the left rear wheel your cell phone is suspect. I know a cell phone can really screw up communications with key fobs. Put your cell phone on the passenger side floor and see if anything changes.

FatsWaller

A further update: GM had their professional grade tool on hand as promised this morning, and it took all of 1 minute or less to reset the sensors. The service adviser did as I asked, and started at the LR wheel, then counter clockwise ending at the LF wheel. I observed this directly. And, they didn't charge for it. As HOXXOH posted, this effectively swaps front with rear, but keeps the same side. Took it out for a drive, with the Garmin on, but with cell phone turned off. Within 1/2 hour, got the message and the DIC showed that the LF sensor wasn't sending. Because of the swap, this means that the LR sensor wasn't sending, and that's what was showing when the problem was happening before. A coms error would have reported that the LR sensor was at fault. Since the fault followed the sensor, this to me pretty much indicates that the LR sensor was close to DOA, so I'm having a new one installed later this week. Maybe I can get a refund from Amazon, even though I'm outside of the return window. Just bad luck I guess that the one (so far) defective unit landed in the LR position so that it became more difficult to analyze the problem.

GMJim

What an unlucky coincidence that you would get a bad new one and it would be on the same wheel. I wouldn't buy any lottery tickets for a while.

FatsWaller

Even though changing the order in which the sensors were programmed seemed to show the LR sensor was defective even though it was new, that may not have been the case. I had it replaced a few weeks ago, and the same error occurred yesterday while driving to the Boston area. Because it's about a 9 hour drive, it gave some time to investigate and today I pretty much proved that the Garmin 2595LMT is causing the problem. The error occurs around 30 to 45 minutes after the Garmin is turned on and always results in an error from the LR sensor. If you turn the Garmin off, almost immediately the LR sensor starts reporting again. You need to restart the car to get rid of the yellow tire light on the dash. I'm not saying that this is a problem with all Garmin models, but certainly with this one. I suppose that it's not impossible that there wasn't a double fault where the previous new sensor was bad as well, but right now the error condition is very repeatable. Maybe the 'traffic' feature and its external cord mounted receiver is responsible? No cell phones were powered on in the car, and no other external electronics present.