Tire Pressure Monitoring System

While they are not as accurate as those on my German cars I find my 575M sensors to be within a pound of my digital gauge and consistent on all four wheels. I don't know the answer to your ECU question. I do recalibrate when I add air to the tires but I can't tell you what it does other than to make me feel like I have done somthing I need to do!

 

The SD2 is used to set up the monitors by tire manufact. and size. it is then set to calibrate when you have all of the same at 2.2 bar thus it knows what the pressures should be from calibration state.

Button in the car just resets the unit.

If you are just checking pressure it's no big deal 1-3 lbs. off.

 

It is what it is. We all know who the best team is! Go colt.

 

Mine are within 1 psi of my Longacre gage.

 

Its a German system, BERU to be exact.

And you may already know what I think of German systems and electronics.

If I had a 575 I would just turn it off.

What a POS. They are just like Microsoft, let the public be the testers and fix it 3 or 4 generations later all the while introducing new bugs.

The Longacre system probably costs more than $150 so no car manufacturer would even consider it.

 

I really only have experience with the BERU system in the Ferrari so I have no basis for comparison but I do know theirs is a real POS.

I have a gauge and it works every time and unlike a Ferrari TPMS when it breaks it is a cheap fix.

The BERU system is not ready for prime time but thanks to Uncle Sam now every car is going to have a TPMS so we can make the US energy dependant. We are held hostage by OPEC because our tires are underinflated don't you know.

 

I had to replace the tpms ecu on my 575 because the warning lights would never go away. It was ridiculously expensive. Whether it needed to be replaced or it was the typical Ferrari 'just replace everything' response I don't know -- its hard to argue with electronics. I also run nitrogen in the tires and the pressure never varies anymore.

The correct pressure for the yokohama advan sports are 33psi in case anyone wants to know; their technical support department is amazing. Try calling Michelin's tech support and see if they can tell you what the proper tires pressure should be.

 

I like their tires but all they will tell you is they are black and round.

 

If by some chance you need the ECU let me know. I have one I will give you at cost to get it off the shelf.

 

Terry -

I'll start by confessing that I don't know a damn thing about the TPMS in a 575M..... but (big but!) the pressure sensors were superseded to a new number (224549), and I wonder if it has something to do with durability or precision. Have you had the tires off the wheels before?

 

Ah...Island Park...There are some nice fish around there... There used to be this guy who ran a restaurant there at the north end of town. He is now out of business. We brought our fish in once and he made us a really nice meal. Only away from civilization and all its rules can you get away with that.

As to the TPMS in the vette it works if you keep everything stock. Trackers had problems because the car would not run if you ran race tires at different tire pressures than the car expected or if you ran your race tires and left the RF valve stems out. But with time the vette guys figured out how to turn those dumb things off at the ecu and basically only the guys with tottally stock streetcars run them. Even many with different tires or aftermarket wheels and deleted the TPMS. I am sure your life would be much easier if you just turned the system off if it can be programmed out and just add checking your tires into your pre-flight checklist.

 

You are correct. I do not know the CAN issues when you try to extract ECU's the main ECU wants to see. I am not even sure if you take the target tpms ecu out and start the car if that may screw something up so that plugging the tpms back in will require the SD2 to tell the main where to look? I can envision all kinds of problems but hopefully you can just unplug it and plug it back in if it does not work. 20lbs here and there add up. If we all just were responsible and used our tire guages when appropriate, checked out oil, looked at our gauges, flipped our own suspension by knob etc...could we get our 3700lb beasts down to 3000lbs? I'd like my 500hp in a light nimble 3000 or better yet sub 3000lb package.

 

If memory serves me correct, the dash is the only item which expects the TPMS CAN signals as inputs. There is some NM, but nothing that can't live without it. If you unplug it, you will get the TPMS Service lamp appearing on the dash, but nothing will be adversely affected, you will just have to live with the warning lamp until you can get the dash config changed.

Cleaning the contacts on the ECU is unlikely to make a difference as the AMP connector tends to seal very well. Couple of things which are worth checking are that no pins on the ECU have been bent, and also that none of the contacts have pulled back from the wiring loom connector.

If you have problems with the TPMS, remember that key on / off won't solve anything as it is on a permanent battery feed I believe. Key on / off just puts it into / brings it out of sleep mode. Unplugging the connector is the only way to properly reset it.

The system does not know what the tyre pressures on the car should actually be. If it did then people wouldn't be able to tweak their tyre pressures down without risk of moving closer to the warning limits if they were pre-defined. When you press the button and complete a calibration, you are telling the system that the pressures in the tyres are the pressures that they should be at (hence why it should be done at 'cold' and not after a drive). It then uses these as a reference. If the pressure drops to 75% or less of the recommended pressure (which you have told it by the calibration) it must display a warning to the driver (this became law from Sept 2007 onwards). There are also conditions for warnings such as rapid pressure loss. The other reason the system has to be calibrated is so that it can learn what wheel sensors are fitted to the car. Some other systems out there require you to go to the dealer should you fit a new wheel sensor (e.g. if your tyre fitter destroys your sensor when changing tyres).

Nothing like a broad sweeping statement is there.

Last time I checked a gauge didn't have a life expectancy of over 5 years on one battery, be expected to work in conditions from -40°C to +120°C, have to survive loadings of over 2000g, and the list goes on.

Rather a lot of the problems on cars tend to be a combination of the owners not properly understanding what they should be doing, and the dealers being far too eager to just replace parts rather than actually understanding the problem.