Need help with TPMS 2004 Cayenne-S

[6182pump]

Hello,

I hope that one of you might be able to shed some light on a TPMS problem that I have. My 2004 Cayenne-S (49K miles) had the tire pressure control unit (#955-618-160-05) replaced by the dealer (Nor. Cal.) six months ago ($591.00) due to a problem reading incorrect pressures intermittently. This immediately solved the problem I was having, which is slightly different to what is now happening, but still similar. Two months ago I had new tires installed and it took about 1 week for me to finally get the Navigation system and TPMS programed correctly so the computer would stop giving erroneous flat tire or workshop codes. Life was good again! Now, several weeks after the tire installation, all of a sudden I am getting erroneous flat tire or workshop codes once again. The car has not hit any curbs or potholes, this similar problem started while driving at freeway speeds and the computer stated I had a flat tire, which I did not. I have double checked all tire pressures early in the morning when the tires are cold. I reset all computer settings so that the system states that it is in learning mode. In 20 minutes of driving/relearning it will either give a workshop code or does nothing and just states that it is still in learning mode. When this problem returned last week I also noticed that sometimes the comfort settings would be forgotten and have to be reprogrammed. I have done all of the following in varying sequences:

Reset NAV system to recalibrate tires. Reset NAV system to factory settings. Reset/reboot NAV system using 1, 4, 8 PCM reboot. Reset main computer system to proper tire type, size and load. I have tried your solution for doing a partial reboot of the system using the key and waiting 30 seconds, then removing key and unlocking door (seemed to solve comfort issues). The main computer just doesn't seem to be able to relearn the pressure settings at ANY of the four wheels, everytime I restart the car it states that the TPMS is turned off/in learning mode. The TPMS batteries in each wheel still have 23 months of life left according to the dealer. I can't believe that the tire pressure control unit is faulty again, but maybe it is. The TSB's on the Cayenne-S TPMS is beyond my scope, but interesting.

I hope that someone can suggest something else for me to try or else it's back to the dealer. If you can help I humbly thank you in advance!!!............................6182pump

[wvicary]

A trip back to the dealer is in order, the system needs to be scanned using the Porsche tester otherwise it's all just guess work.

[RFM]

I'm with wvicary, a visit to the dealer is the only option. Too complicated especially on older Cayenne.

[Jaybee52]

I had a similar problem, looked at the TSB and thought a little OTT. However by accident I solved the problem. With a bit of luck you too may be the victim of the dodgy Tyco connector. The TPMS control box is located just above the drivers footwell to the side of the steering column. (my car is RHD, should be the same of a LHD). the box has a single multiway Tyco connector with a locking cam. If you have a close look at this (the control box is a push fit in its housing, carefully pull it out) the locking cam (the purple bit) spigots break off and allow the connector to come loose with various contacts breaking connection or causing poor connections. You can buy a new connector body or devise another method of retaining the connector in the module (a small tie wrap works fine). Since I did my one never another problem

Good luck

[6182pump]

The answer to this problem turned out to be 4 new TPMS sensors, one per wheel. The rear 2 stopped transmitting, and the front 2 had less than optimum voltage, and were weak. New sensors may last as long as 8 years, Porsche is now saying to replace problematic sensors after 5 years if need be. As my Cayenne is an early '04, with a March '03 build date, I got less than 6 years of battery life, with no way of knowing how long they sat on the shelf before being installed in my Cayenne back in '03. This problem will probably become more prevalent to others in the future. Anyway, life is good, and thank you all for your help...........6182pump.