Tire Press. Monitor Inoperative (message)
Thread Starter
Junior Member
Joined: Feb 2011
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2008 C350
Tire Press. Monitor Inoperative (message)
I recently began seeing the message on my speedo screen saying, "Tire Press. Monitor Inoperative". It is intermittent. I have been to the dealer once about this, and they can't find anything wrong. It is not a problem with pressures, but obviously either a problem with one of the senders or the receiver. Anyone else have this problem?
Member
Joined: Jul 2008
Posts: 237
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From: Burlington, VT
2008 C300 Sport 6M
I had this issue too for quite a while. It was especially annoying because even when I would clear the message the tire pressure indicator stayed illuminated. I checked the pressures and then of course as soon as I made an appointment with the dealership, the problem just went away.
Can't help you but I feel your annoyance.
Can't help you but I feel your annoyance.
Thread Starter
Junior Member
Joined: Feb 2011
Posts: 30
Likes: 0
2008 C350
I had this issue too for quite a while. It was especially annoying because even when I would clear the message the tire pressure indicator stayed illuminated. I checked the pressures and then of course as soon as I made an appointment with the dealership, the problem just went away.
Can't help you but I feel your annoyance.
Can't help you but I feel your annoyance.
Member
Joined: Oct 2008
Posts: 230
Likes: 1
From: Niskayuna,New York
2009 C300 Sport 4MATIC™ Sedan
Member
Joined: Oct 2008
Posts: 230
Likes: 1
From: Niskayuna,New York
2009 C300 Sport 4MATIC™ Sedan
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Thread Starter
Junior Member
Joined: Feb 2011
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2008 C350
follow-up on the problem
Replacing the wiring harness didn't help. Then they replaced the TPM receiver somewhere behind the dash. That didn't help.
I suppose they will now replace the sending units in the wheels, which probably would have been the simplest, cheapest thing to do in the first place.
Oh well...
I suppose they will now replace the sending units in the wheels, which probably would have been the simplest, cheapest thing to do in the first place.
Oh well...
MBWorld Fanatic!
Joined: Feb 2004
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From: SEATTLE WASHINGTON USA
'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
Must have been something else because as long as the sensor is inside the tire, it's still reading the pressure.
This happened to my car when it was new and the dealer installed my Bridgestone tires and the "tech" broke the sensor off with the tire mounting machine. It was clunking around in there for a week or so causing balance problems but no warning lights.
This happened to my car when it was new and the dealer installed my Bridgestone tires and the "tech" broke the sensor off with the tire mounting machine. It was clunking around in there for a week or so causing balance problems but no warning lights.
Thread Starter
Junior Member
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2008 C350
these people are idiots...
Replacing the wiring harness didn't help. Then they replaced the TPM receiver somewhere behind the dash. That didn't help.
I suppose they will now replace the sending units in the wheels, which probably would have been the simplest, cheapest thing to do in the first place.
Oh well...
I suppose they will now replace the sending units in the wheels, which probably would have been the simplest, cheapest thing to do in the first place.
Oh well...
This isn't just local service people... the MB tech gurus are telling the local techs this. They don't know what they are doing, so they fall back on the lamest excuse possible.
Thread Starter
Junior Member
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2008 C350
I owe MB Techs an apology
So, now they are telling me that the aftermarket backup camera I installed (see cyclops thread) is causing the TPM to fail. Despite the fact that the TPM worked fine for the 1st 7 weeks I had the camera. And the fact that a zillion people have done this camera install and no one has a problem with TPM.
This isn't just local service people... the MB tech gurus are telling the local techs this. They don't know what they are doing, so they fall back on the lamest excuse possible.
This isn't just local service people... the MB tech gurus are telling the local techs this. They don't know what they are doing, so they fall back on the lamest excuse possible.
Member
Joined: Jul 2008
Posts: 237
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From: Burlington, VT
2008 C300 Sport 6M
Wow as you were posting I totally agreed with you that the camera was a lame excuse by MB. Insane that it ended up being the actual problem. Are you going to end up adjusting the camera system to be usable?
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2008 C350
I may wait until the warranty runs out, given that the dealer spent a week diagnosing the problem and didn't charge me anything.
MBWorld Fanatic!
Joined: Feb 2004
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From: SEATTLE WASHINGTON USA
'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
Not right away. If I do, I will replace the entire cable with a fully shielded one, and set the camera to be powered by the backup lights again.
I may wait until the warranty runs out, given that the dealer spent a week diagnosing the problem and didn't charge me anything.
I may wait until the warranty runs out, given that the dealer spent a week diagnosing the problem and didn't charge me anything.
Thread Starter
Junior Member
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2008 C350
I'm not surprised that most people do not have any problems. I made 2 mistakes; 1) leaving a break in the shielded wire carrying the video signal which allowed RF to escape, and 2) wiring the camera so that it was powered all the time the car was on. My problem was likely due to this combination of mistakes. If the camera is only on during the few seconds you are in reverse, it is unlikely to produce interference long enough to cause a TPM fault. If I had used a continuously shielded cable, it probably wouldn't have mattered.
Member
Joined: May 2011
Posts: 139
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From: Jersey
2008 C300 w204
My car has this problem and I just got it a week ago. I have a bubble on 1 tire and I'm still waiting on the dealership to order a new one for me so I was kinda hoping that was causing the problem.
Super Member
Joined: Jan 2009
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From: Savannah, GA
2021 G63
i had the TMPS inoperative warning issue too, the dealer blamed it on my 22's which have been mounted for almost 2 years prior. they said the valve stem does not stick out enough and it's causing the problem. which really does not matter becuse the sensor is on the back side if the valve stem? the light came for about a week, i took it to the dealer, they cleared the warning. and said if i put my factory 20's back on it won't have the warning come up anymore. it came on for 2 days after i left the dealer, then went off and has not come back on for 8 months now. I think it was just a glitch?
