Pico Parking Sensor Tester TA329

I have a customer with a parking sensor issue the problem is currently on the back burner until I return from holiday but when I saw the Pico Automotive Parking Sensor probe Link to Pico page I thought thats a good tool and the price is fair so I ordered one.
It promptly arrived an tested Okay although the signal gain is a little low. I quite like it, how useful it will be as a diagnostic tool I don't know yet but it occurred to me you could DIY your own using either a 2 wire reverse sensor or a cheap ultrasonic transducer from Radio Shack or Maplin, eBay or Amazon.

Link to Pico Guided Test

That's pretty cool, I've never had to troubleshoot one of those systems.
After reading the Pico test description, I can see how you'd be able to rig up a tool to measure the signal using an old sensor like you say. But for the price, why bother?

I saw the video on the Pico channel recently. Thought it was cool and handy but didn't ever bother to check out the website and see how much it costs. Now after reading Andy's post I saw it's only 25 bucks :woohoo: That's cheap!

I'm buying one for sure!
Thanks Andy

That Pico parking sensor testing page is blowing my mind. :ohmy: I had no idea these things were so complex!

I finally go a chance to try out the Pico Parking Distance Sensor Probe.
This from a late 1990's /early 2,000s Range Rover

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almost the same system as used by BMW
The customer complaint system not working emmiting a constant beep when reverse gear was engaged.
Traced turned out to be one faulty (dead) sensor



The trace below is from a home build probe which was simply a 2 wire aftermarket parking distance sensor.




Conclusions
(1) The Pico PDS probe made it very easy and quick to find the dead sensor.
(2) Scope settings took a bit of tweaking to get right.
(3) The home build probe also works and produces a higher voltage amplitude signal than the Pico PDS probe.

That's a neat tool. I wonder if it would work with a Vantage? I had to troubleshoot one of these on my 08 Honda Odyssey Touring. The message on the gauge display just says check parking sensor, and gives a long beep, but gives no details on what to check. With this vintage of Honda, the other sensors continue to work even when one fails so I simply put the car in reverse and drive and listened for the chimes when I walked in front of each of them. I found one on the front that didn't chime when I walked in front of it. I simply swapped it to the other side to confirm the sensor was the failure. On some later model Hondas even a burned out bulb in the switch can cause the message to appear. I didn't connect the Autel to it to see what data pids are there for them but I could easily reach the sensors after removing one screw from inside the inner fender lining so that seemed faster anyway.

On the Rangey I had no way into the system I and one bad sensor took the whole system down so using an ultrasonic probe was the only easy way to identify the bad sensor, I had previously scoped individual sensor wires at the module , the 4 sensors are connected by 5 wires to the PDC module, each sensor sends and listens on the same wire and they share a comon ground. to the parking distance module but really didn't find anything useful back probing at the module except the module had good powers and grounds and was talking on the bus.

I'm gonna go very low tech here but I always put my finger on the sensors to spot a dead one. You can feel it.

Dylan wrote: I'm gonna go very low tech here but I always put my finger on the sensors to spot a dead one. You can feel it.

:ohmy:
Wow! I'm going to try that the next time I see one!

So Andy, what can we discern from those waveforms? Are those captures of functioning sensors? The Pico seems to show some oscillations that the home made didn't pick out.

Love the scope captures, Andy.

Dylan, you're blowing my mind over here! I'm gonna try that on my parking sensors today.

So I couldn't feel the sensors working with my finger, but I definitely could hear them. Each sensor made a distinctive tick about every half second. Nice quick testing tip, Dylan!

Tyler wrote: So I couldn't feel the sensors working with my fing er, but I definitely could hear them. Each sensor made a distinctive tick about every half second. Nice quick testing tip, Dylan!

COOL. Yeah it's a quick test for spotting a dead one. Not high tech but it can help

I'm not sure what you would gain from knowing the wave form. Those sensors either work or they don't. I listen to them with my stethoscope and if ones not clicking I peel the bumper cover off and look at the bumper harness. The sensors themselves rarely fail unless damaged. It's almost always a broken wire.

I've only seen one sensor that was clicking and not working. But I think after the whole thing was done it just had to much paint on it from a previous body repair.

Andy.MacFadyen wrote: On the Rangey I had no way into the system I and one bad sensor took the whole system down so using an ultrasonic probe was the only easy way to identify the bad sensor, I had previously scoped individual sensor wires at the module , the 4 sensors are connected by 5 wires to the PDC module, each sensor sends and listens on the same wire and they share a comon ground. to the parking distance module but really didn't find anything useful back probing at the module except the module had good powers and grounds and was talking on the bus.

Not sure what you mean by listens and sends on the same wire. If the system was doing the solid tone thing and never stopping then it's not faulted out yet and thinks your right up on top of something. Kind of shows the circuits intact from a seat of the pants thing and does in fact indicate a faulty sensor. If it had a solid tone then shut off like I think you said yours was doing then you usually find one not ticking and a harness behind the bumper cover broken.But those early sensors did have a water intrusion problem.
The I bus connecting the system to the inst pack is a LIN bus on this system but later it was on a CAN network and takes on the job of rear view camera and then after that surround cameras.



Learning your board here but I hope I've attached a schematic of the system you mentioned. Pretty much the same system in all Land Rover Products.

Nice, thanks for the schematic Skip!