kmcapitals8

So my 2003 s500 has been with me for a year and 2 months about. When i first got the car, the car locked with the keys however, when it locked the first time i pressed the lock button the alarm went of with the lights, no sound, and then id press it again, and it locked and the alarm stopped, however after some time it stopped locking. To explain, i would come out in the morning and it would unlock, now if i did not start the car, say i got something from inside the car, i could lock the car, but the alarm with the lights, no sound, would go off and i would have to press the lock button on my key again, and then it locked and the alarm stopped, but if i unlocked the car and drove somewhere, it would not lock with they key button so id have to manually lock it. So i had my mechanic take a look and he thought it was the pse pump, but when he put a different one in, he says he reprogrammed it to the car which i believe because i have trusted him for years and he has the software to do it, it still did the same, so i was left clueless. then i went to another mechanic and he said that there was a communication problem with the modual and the remote and only a dealer could do it because of safety reasons with the immobilizer and he did not have the software to do it and only the dealer could fix it. so i went to the dealer and they tested the com bar because i had rear tinted windows, with the infrared and radio frequency but they ruled that out most likely saying it still didnt work when they blocked the com bar signal. The dealer than said the pse pump was throwing out a lot of error codes, i will out the print out in this thread. he said i need a new pse pump and they gave me an estimate of around $1300, 900-1000 for the parts, and labor plus tax, etc. now i am not crazy enough to spend that money on a part that is basically going to be worth a fifth of my car. So i have a few questions. I asked the dealer if i bring them a part and they could reprogram it and they said yes, but no guarantee it would work given its not the part they order, so my question is has anyone dealt with buying a used or oem pse pump, having the dealer reprogram it, and it working, also can anyone tell me what the codes actually mean, like is the circuit in the pump fried, or is it leaking etc. any other advice or knowledge would be greatly appreciated. The dealer said it is most likely the pse pump, but its a 1200-1300 dollar bill, i want to be certain. They said that my mechanic probably did not reprogram it correctly and so the other one didnt work either. and one last thing, i am a bit hesitant on the pse pump because the car's immobilzer or alarm goes of after i am able to lock it with the key, if anyone can give an input on that. Thanks for your time

MikeKerr7

KM, what state do you live in? If you are in the PA, NY, NJ, M area I may be able to help.

kmcapitals8

I live in NJ, but i am out in the midwest region now for college. Anything you could think of that you have seen or experienced with this issue?

tusabes

I have a feeling it's the alarm siren box . It has an internal non replaceable lithium battery and at this age they are all failing

ibeforreal

I'm thinking the same thing as Tusabes. I would have that alarm checked out before buying anything else. It is under the driver's side front fender behind the plastic covering.