Yet Another Parking Sensor Test For You

[arryp0tter]

:P right here we go i recently bought a 2002 1.9tdi at a bargain price i might add but have spent a bucket already, anyway back to the story. i have the usual parking sensor problem, engage reverse both buzzers go off continually for around 10 seconds then cut out and light on switch flashes continually to indicate a fault.

 

heres where it gets interesting.

i have ignored the 'check for a tick' from the sensor to see if its working.

i have stripped the front and the rear of the car established that there is a pwer feed to eachsensor ( red wire) there is an earth to each sensor ( brown) and that there is a 'signal' being sent from the sensor when plugged in this being on average around 9.5 volts each sensor has its own wire colour front and rear for the signal wire. anyway this information tells me there is a signal coming out of each sensor so THEY MUST ALL BE WORKING would you agree on this ok i hope you do . now i have also had the standard issue from Fraud with the parting of the rear screen wash pipe ( this was found to be open upon purchase ( one of the first thing i checked having had a flood regularly on my old mk1 ) so it is unknown how long this had been leaking for asume ages . i am thinking that despite there being no obvious signs of water damagethat the unit is indeed toasted. I have not checked to see what is coming in to the unit as there are too many wires and you just cant get to them all to get a voltage reading with this info would anyone like to hazard an educated guess at my diagnosis

I NEED A NEW UNIT LOL

thanks in anticipation for the generous help this is THE best ford help forum going.

[Mirez]

:P right here we go i recently bought a 2002 1.9tdi at a bargain price i might add but have spent a bucket already, anyway back to the story. i have the usual parking sensor problem, engage reverse both buzzers go off continually for around 10 seconds then cut out and light on switch flashes continually to indicate a fault.

 

heres where it gets interesting.

i have ignored the 'check for a tick' from the sensor to see if its working.

i have stripped the front and the rear of the car established that there is a pwer feed to eachsensor ( red wire) there is an earth to each sensor ( brown) and that there is a 'signal' being sent from the sensor when plugged in this being on average around 9.5 volts each sensor has its own wire colour front and rear for the signal wire. anyway this information tells me there is a signal coming out of each sensor so THEY MUST ALL BE WORKING would you agree on this ok i hope you do . now i have also had the standard issue from Fraud with the parting of the rear screen wash pipe ( this was found to be open upon purchase ( one of the first thing i checked having had a flood regularly on my old mk1 ) so it is unknown how long this had been leaking for asume ages . i am thinking that despite there being no obvious signs of water damagethat the unit is indeed toasted. I have not checked to see what is coming in to the unit as there are too many wires and you just cant get to them all to get a voltage reading with this info would anyone like to hazard an educated guess at my diagnosis

I NEED A NEW UNIT LOL

thanks in anticipation for the generous help this is THE best ford help forum going.

 

 

You can't make the assumption they are all working just because you get a voltage on the signal line as you don't know what you are measuring there. If its an analogue signal it could be putting a "dead" signal out in the low Hz which would show as a voltage, and a "healthy" signal of faster Hz would still show a voltage of similar reading. Without knowing exactly what the sensor sends, measuring a voltage from it is almost irrelevent.

 

I wouldn't ignore the "check for tick" suggestion as that will tell if the sensor is actually doing anything, VagCom would tell you if you have a sensor gone though, and more importantly it would tell you which one(s).

 

That said my own reasoning would probably lead to to conclude the same as you that the controller is defective.

[arryp0tter]

thanks for your input Mirez and again from what i have read regarding these sensors ( found a very good reasoning on a bmw site ( apparently some use the same sensors) the frequency thing is logical i have me a vag=com just not round to firing it up yet so maybe i will install it and give it a road test thanks for the help i enjoyed a wasted afternoon in the sun putting my tests into action lol

:P right here we go i recently bought a 2002 1.9tdi at a bargain price i might add but have spent a bucket already, anyway back to the story. i have the usual parking sensor problem, engage reverse both buzzers go off continually for around 10 seconds then cut out and light on switch flashes continually to indicate a fault.

 

heres where it gets interesting.

i have ignored the 'check for a tick' from the sensor to see if its working.

i have stripped the front and the rear of the car established that there is a pwer feed to eachsensor ( red wire) there is an earth to each sensor ( brown) and that there is a 'signal' being sent from the sensor when plugged in this being on average around 9.5 volts each sensor has its own wire colour front and rear for the signal wire. anyway this information tells me there is a signal coming out of each sensor so THEY MUST ALL BE WORKING would you agree on this ok i hope you do . now i have also had the standard issue from Fraud with the parting of the rear screen wash pipe ( this was found to be open upon purchase ( one of the first thing i checked having had a flood regularly on my old mk1 ) so it is unknown how long this had been leaking for asume ages . i am thinking that despite there being no obvious signs of water damagethat the unit is indeed toasted. I have not checked to see what is coming in to the unit as there are too many wires and you just cant get to them all to get a voltage reading with this info would anyone like to hazard an educated guess at my diagnosis

I NEED A NEW UNIT LOL

thanks in anticipation for the generous help this is THE best ford help forum going.

 

 

You can't make the assumption they are all working just because you get a voltage on the signal line as you don't know what you are measuring there. If its an analogue signal it could be putting a "dead" signal out in the low Hz which would show as a voltage, and a "healthy" signal of faster Hz would still show a voltage of similar reading. Without knowing exactly what the sensor sends, measuring a voltage from it is almost irrelevent.

 

I wouldn't ignore the "check for tick" suggestion as that will tell if the sensor is actually doing anything, VagCom would tell you if you have a sensor gone though, and more importantly it would tell you which one(s).

 

That said my own reasoning would probably lead to to conclude the same as you that the controller is defective.