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Discussion Starter #1
I have a 97 S420. Parktronic worked with no problem until I had to get it painted. Two things are different from before I painted anything:

1. The front bumper had to be replaced so I got a new one and transfered all the sensors from old bumper to the new. I did brake the lock on the connerctor (there's a lock on the connector on the wire for the sensors going from the body to the bumper, in the left wheel well)


2.The rear bumer was ok but I had to align it a little bit so I had to take it off. There was a small connector on the driver's side that went into the trunk on the CD changer side. When I pulled the bumer off I did not see what it was connected to. By the looks of it it is a ground or antenna of some sort because it is connected to a metal flexible plate in the corner of the bumper. The wire is a single lead wire. The connector for the parktronic sensors is on the passenger side and was not difficult to find and reconnect when I put the bumper back



Now that I have the car all together the biggest dissapointment was when I started the car was that the parktronic system showed two red bars on both sides (no yellow barrs at all), it beeped fro a while and then shut itself off.
I looked for a fuse for the system and could not find it.

Anybody know what it could be? Please, help! Thanks in advance.
 

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take it apart and do it right. it's user error. what do you expect anyone to tell you?

it's a touchy system. if you pointed a sensor badly it will read wrong and throw weird things

if you painted over the sensor covers, same result

and of course check if you screwed up wiring/connections. almost sounds like it is not making contact to the sensor array. why, well gotta be there to figure that part out
 

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The sensors need to be orientated on the correct axis. The wires comming out of the sensors should line up on the horizontal plane. On the front bumper look at the foam rubber blocks that go behind them. They have cut-outs for the wires. If the sensors are 90 degrees off then they will be too sensitive in the vertical plane and pick up the ground as an obstacle. Unfortunately you’ll need to take the bumpers off and rotate the sensors. Been there, done that.

Do the front bumper first because the rear system is only active when the car is in reverse.
 

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The sensors need to be orientated on the correct axis. The wires comming out of the sensors should line up on the horizontal plane. On the front bumper look at the foam rubber blocks that go behind them. They have cut-outs for the wires. If the sensors are 90 degrees off then they will be too sensitive in the vertical plane and pick up the ground as an obstacle. Unfortunately you’ll need to take the bumpers off and rotate the sensors. Been there, done that.

Do the front bumper first because the rear system is only active when the car is in reverse.
Very well said!! And politely:)
 

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Be sure the wiring harnesses for the 6 sensors in front, and 4 sensors in back, is intact. If any of the wires are broken it will error out, as you are experiencing. Usually, when the bumpers get hit, even lightly, it can throw the wiring out. And if even one sensor is non-functioning, the whole line will not work, sort of like Christmas tree lights.
 

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Discussion Starter #6
Thank you all for your replies. Few things:

1. Orientation. I was carefull not to screw up the orientation and the order in which they were on the bumper and as falconspirit pointed out the foam has cut outs which makes it impossible to put it in the wrong way, the cut outs in the foam force you to put the correct sensor where it belongs. Moreover, the outside flange on the sensor makes it impossible to place them upsidedown, it would not fit to the bumper.

2. Christmass tree lights thing. This is what I was hoping to understand. Though I didn't pay that much attention but visually I remember or may be I just assumed since it just makes sense, that the system is wired in parallel i.e. an individual failure will not render the whole system useless.

So, before I start taking my front bumper apart again, I note a few things and guys, if you have experience with this system correct me:

a) it is not possible to put the sensor upsidedown because of the flange on the outside. Even if I could, it should saturate one or two sensors and the display would show something to be close, i.e. all yellow bars are on plus the two red bars are on. Mine just shows two red bars no yellow, indicating that something wrong with the system.

b) you can paint over them, there was old paint on the sensors. Unless it is some special paint (hmmm that could be a possibility, I guess one way to find out is to call the dealer and see if they are selling them by color, thinking out loud here :)

c) good point regarding the rear ones. They are the least played with, i.e. I didn't take them off the bumper, and hopefully, given I assume correctly that the sensor can be painted, I should be able to see if those work and if they don't whatever the central place where the signals are analysed needs to be checked. Anybody knows where/what that is? Anybody knows where the fuse/relay for this system is? I could not find it in the two fuse boxes (under the hood and in the trunk)
 

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It is doubtful the orientation is the problem. These sensors are round tube-shaped units, so how would you know which end was up?

They ARE very sensitive to painting and cannot sustain more than two light coats of paint, that's color and clearcoat. They DO sit in a plastic collar that fits into the bumper and there are a couple of different shapes to the collars for the same car, they differ around the corners I recall.

You may have a bad sensor. I personally think that is your problem. As stated, if one is bad, or the wiring is not right or damaged, you will not get it working right. One failure will fail the entire set. That's what the interior time-out feature is telling you.

Someone who could help you out would be a competent body shop, if you don't want to visit the dealer.
 

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As the post above, these things resonate at 22khz in the front face, if you paint then too thick they cannot resonate. I would remove them and clean off the paint,,, all that is needed is a couple of passes with an aerosol and they will work just fine again
 

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Discussion Starter #9
Yes the more I think about it the more I realize that it must be the paint. Besides the old paint and the new paint and clear coat there would be a primer there too, right?

Would aceton pain removal save me from removing the bumper? Also, the system worked before the body work. I've been driving the car with screwed up bumer for almost a year and everything worked.
 

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Do the job right.

Take the bumper off, seperate the sensors from their individual plastic frames (which probably wasn't done when you painted the bumpers and the paint/clearcoat is fusing the two pieces together) and take acetone to the front of each sensor. You'll get to a gold-ish color at the bottom of the paint and you'll know you're where you need to be. Repaint and re-clearcoat the sensor fronts and reassemble.
 

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i suggest you read out the codes before messing with the paint. The codes will tell you which sensor is bad.

regards
Odd
 

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@oddemann
How can I read the codes? Do you mean OBD codes, is this system part of it?

On the progress with this issue:
1. I've removed the paint and the system still doesn't work.

2. I don't believe it is a particular sensor since it would seem odd if front and back would have one failed sensor where before the whole system worked (here I'm assuming that if one, let's say, front sensor failed and I would get the time out for the front, the rear would still work. I don't know if this assumption is correct, though)

3. It is not wired in series: there are two wires that go specifific to each sensor. What ever system is evaluating the signals from these sensors may in fact either ignor a particular sensor or disable the systme because of one failure. This I don't know. Does anyone know where the brain of this systme is?

4. Does anyone know what the resistance is on these sensors and how to troubleshoot them through a connector under the bumper (front or rear)

Thanks.
 

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When the Parktronic system on my 1999 wasn't working, I found that not only were a couple of sensors bad, but the wiring harnesses that connected the sensors were also broken and had to be replaced. There are two wiring harnesses, one for the front, the other for the back. The front bumper has 6 sensors, the back 4, for a total of 10 sensors.

You may have issues with the harness(es). Start with the one that had bumper damage. The harnesses are located just in back of the bumpers.
 
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