Envoy Denali Left Front TPMS issue

[56napco]

Last month I had new tires installed on my 2008 Envoy Denali at my local GMC dealership, everything was good when we picked it up. Two days after the tires were installed the TPMS system showed the Left Front lost signal with just dashed lines in the DIC. Since then I've taken it back to the dealer and they have put three new sensors in the left front wheel, two aftermarket and one GM. There is a GM sensor currently installed. When the dealer gets the truck in they cannot get the TPMS to read or teach the left front, they install a new sensor and it then teaches and reads properly. This lasts for maybe day and not more than 10 miles before the dashed lines come back and it drops the left front again.  I've tried teaching the sensors myself after this happens and nothing happens when I try to teach the left front. The other three wheels all read correctly and have not had issues with them so I can't believe it has anything to do with the tires causing the issue. Everything works except the left front.  Is there anything left to try? I'm getting tired of taking it back to the dealership just to have the same thing happen again when I drive it home and they haven't tried re-programming the BCM.  Nothing else has changed except the tires.  The dealer has stood behind their work and has replaced these sensors without charge but there has to be something else causing just the left front to stop reading that they are not aware of.

[Jsdirt]

Sounds to me like they have NOT changed the sensor, contrary to what they're telling you. They damaged it during install, or coincidently the battery happened to die in it at that particular time. Replacement should fix that - they have the tools to reprogram the new one in seconds.

 

Try another dealer. If that dealer charges you, present the bill to the 1st dealer - make sure you get reimbursed.

[56napco]

So, if they did not replace the sensor but they somehow get it to work for a short time for me to drive home before it stops transmitting again what could the dealer be doing to make it work?  They also have not given any paperwork for the second or third sensor replacements nor have they charged me anything. The issue with taking it to another dealer is the first sensor on the invoice was not a GM part, not sure if that will not be covered by another dealership or if only labor will be covered since it wasn't a GM part and they make me pay for another new sensor.

[Jsdirt]

I'm just guessing here - I can't know what that dealer actually did - I can only speculate, given some dealership history (they're not all bad, but it seems a large majority are).  They could have just left the damaged sensor in place, and told you they replaced it, without ever having touched it. It could be cracked and working intermittently. Again, all just speculation on my part.

 

I'd call GM corporate and tell them what is happening - they should get things rolling in the right direction ... HOPEFULLY.

[56napco]

Well, going to give them one last try before going somewhere else. Truck goes in next Friday and I at least was able to get them to confirm the sensor part number, #25774006, over the phone and will ask to see the old sensor.  I agree that the first sensor may have been damaged and worked a couple days after the tires were installed. Also, I had all four sensors replaced in 2016.

We'll see how it goes this time.

[Jsdirt]

10-4 ... keep us posted.

[diyer2]

I would mark the bad sensor some way to tell if they replaced it.

Something minor, say take a pocket knife and put a small nick in the valve stem.

Any type of mark to identify it.

 

[Motor City Rick]

A dab of figure nail polish or leave a scratch on the valve stem should see if they are doing their job.

[56napco]

Just spoke to the service manager over the phone. They were able to get the sensor to teach but using their TPMS sensor tool, I have only taught the sensors per the procedure in the owner's manual since I don't have the sensor tool.  They also started with the Right Front, which the vehicle then thinks is the left front, taught all the sensors and took it for a ride. GM told them that if after 3 miles the light comes on it will be a sensor issue, after 10 miles it is a BCM issue.  Of course after 10 miles the light came on and still was saying the left front signal was lost, which is actually the right front in this case.  Now, I had the BCM replaced less than two years ago for a TPMS issue which turned out being due to having LED bulbs installed for the license plate lights, so I have a tough time believing the module would have failed already and the only way to fix this is with a $400 module and labor.  I am having them reprogram the existing BCM and we'll take it from there, even though they didn't like trying that.  My thinking is when they first reprogrammed the sensors that the programming became corrupt since everything worked find up until a few days after the new tires were installed.

[Jsdirt]

This is why I tell everyone .. DO NOT BRING an OUT OF WARRANTY VEHICLE TO THE DEALER!!! Same story, over and over. 

 

They screw something up, and the CUSTOMER ends  up paying for it. Get that truck the heck out of that dealer, and find a private garage. 

 

I must've misread the post when I responded thinking it was a '16 - I should've said this in my first post!!

[swathdiver]

I'm no TPMS expert but that sensor's PN# is for older cars and fellas with '07 and especially '08s are always posting about trouble with the TPMS on their trucks.  

 

These 3 work perfect in my 2009: 13586335, 25920615, 13598771

 

Other GM cars nearby, other remotes nearby, other tire sensors nearby can all help foul up a relearn process.  However, since it works for a time and then goes blank, assuming it is a new sensor with a good battery, then the BCM is the assumed problem.  Again however, you may have modified your truck and compromised the integrity, long term, of the BCM and other components, maybe even something aftermarket is interfering with the TPMS in that particular wheel position.  

 

Last month I had another replaced at the tire shop.  They couldn't get it right and even fouled up the other side.  I couldn't get it right either so I put it to bed so to speak for the night.  Worked like a charm the next morning.

[56napco]

So, the reason I took it back to the dealer was because that is who I got the tires from and who mounted them. So that is why I took it back to them, so they could figure out why the TPMS light came on only after they mounted the tires. It worked fine before the tires were mounted and before they taught the sensors.  I would trust the dealers around here more than a private shop. Now in Dubuque, where we work, thats a different story.

 

The part number for this sensor is the only part number that is correct for this Envoy except export models per GM, it's a 2008 Envoy not a 2009.  There is nothing aftermarket, except a K&N filter, on this truck and I have not modified it at all. Otherwise it's completely stock and it's going to stay that way.

 

Regardless, so far the TPMS light has not come back on and the sensor is still reading tire pressure correctly.  Tomorrow will be the real test when my wife takes it to work in the morning.

[56napco]

It's been a week now and no issues since the dealer reprogrammed the tailgate module.