75 Tourer Parking ECU

[MWMan]

I'm trying to get to the parking ECU on my tourer to do some diagnostic tests on the parking sensors. I have followed the instructions in my Haynes manual to remove the rear side panel, and have got to the point where I try and jiggle the side panel around the spare wheel cover and pull it out. All the screws and clips are off, but can I heck as like get the thing to pull away from under the wheel cover near the seat. I don't want to do any damage and if I can, I don't want to have to remove the seats and the spare wheel cover.

Can anyone suggest what I am missing or point me to a How To.

thanks

[GeoffWW]

Your access to the parking sensor control unit behind the rear side lining is the last thing you need to be doing to check the system. There are other more easily done checks you can do before going to the trouble of removing the side lining.

Have you checked the other audible 'indicators' to give an indication of the 'Reverse Parking Aid' and it's non-performance.

When you select reverse gear, do you get a very short buzz to indicate that the RPA is working, or a continual buzz indicating a fault?

Does your reversing light work? If not, the reversing switch on the gearbox could be faulty or maybe a cable has come adrift? Or maybe the fuse has been blown or been removed to stop the warning continual buzz.
Access to the switch is behind the F/N/S/wheel arch cover, just past the various suspension arms. If your reversing light comes on, then the fault is not there.

If you get a continual buzz, this indicates that you have a problem with either one or more of the sensors on the rear bumper or a bad connection on the cabling feeding one or more of them?

On the sensors themselves, with reverse selected, placing an ear close to each of the sensors, can you hear a almost inaudible buzz from all four of them?. They should all buzz. Any not buzzing need to be checked on the cable connections and the main connector, 'inside the bumper', accessed from underneath .

If you have a continual buzz on selecting reverse above, do any of the sensors have paint bubbles on the painted flat surface of any of the sensors. The air-gap under the paint bubble gives the same effect as the car being parked right up against another. Any bubbling should be carefully removed and the sensor face repainted. Once all the above are checked out, I am sure you will have found the problem and have no need to remove the side lining

If you still have to remove the side lining, have you removed the rear seat side bolster. The side panel you are trying to remove has a screw fixing it to the wheel-arch under the bolster. The side panel should then be 'rolled' inwards at the upper edge and the lower side 'unhooks' from below the floor panel.

Hoping this helps

Geoff

[MWMan]

Hi Geoff

I am actually trying to follow up on a thread started by mac-1990 "Parking sensors not working at all", in which I asked a question about my sensors. I do have reversing lights, I cannot hear any clicking at any of the sensors when in reverse. The sensor paint covering is good. I do get a continual tone for about 5 seconds when reversing off the drive.

Daznkel sent me some photos of how to do some continuity checks, but it needed access to the parking ecu. I have removed the bolster on the rear seat and the screw that is behind it. The side panel is very loose, but I just can't seem to roll it clear of where it catches under the spare wheel cover near the seat. Having got this far I will continue trying to get the thing off today and if need be I'll remove the spare wheel cover. Following the testing, I have no doubt I will have to be into the wiring in the bumper. Your detailed notes will be very helpful.

many thanks

Quote:
Originally Posted by MWMan View Post
Sorry Daznkel - I had a bit of computer trouble while posting!

My connie is an auto tourer, and I do have a multimeter to carry out any fault finding. Any tips would be gratefully received.

thanks
No Problem.

Locate the parking ECU in the boot behind the black lining on the right hand side.



Remove the black connector from the rear of the parking sensor control unit. Start the car, get someone to engage reverse. Ensure the reversing lights are on. Measure the voltage between the following;

Pins 1 & 6 = Approx 12V (This is the power supply via fuse 2)
Pins 12 & 6 = Approx 12V (This is the reverse relay feed via relay R217)
Pin 6 is the Ground.

Here is a pic on the connector you are looking for showing the numbering;



Post back with your findings.

[Mike Noc]

When I had the long beep and then nothing when selecting reverse it was down to one of the sensors being faulty.

As your reverse lights are working and you are getting a warning beep, the next two common faults are a faulty sensor or corroded/damaged wiring.

[GeoffWW]

Hello again MWMan,

I have just seen your reply and the other from Mike Nok. I am not sure as to whether you have to unbolt the load-space cover side clamp from the top of the wheel arch. (see below. This has to be removed according to the Haynes Manual).

Can you move the top round part of the arch cover away towards the middle of the car?
If you raise the spare wheel cover/floor of the load area all the way up (on it's hinge), it gets in the way of the side cover you are trying to remove.
You need to raise the floor panel only a few inches at the tailgate end, and lift the side panel's rear end out of the sunken pocket to the rear of the wheel arch, rolling the top pf the side cover to the middle, just enough to 'ease' the side panel's lower fold out from under the partly raised floor, moving the cover back as far as the bodywork allows.

After writing the above, I have just referred to my Haynes Book, which, although not favoured by many Forum members does give a detailed procedure, albeit with rather dark pictures, on pages 11.35 and 11.36 from para 84 to 94, including the loadspace cover locking mechanism on top of the wheel arch.
Are you sure you have released all the fixings shown in the various photos, including the two clips shown in photo 25.92, under the edge of the floor? Photo 25.93 shows the opposite side's panel being tipped over onto it's side to release the panel.

[MWMan]

Goeff / Mike

thanks for the further info. I did finally manage to get the side panel off using a bit of brute force to get the panel to come out from under the spare wheel cover. The Haynes manual was pretty good at walking me through the removal except as you say the quality of the photos. Once I got in there, I managed to get the plug out of the ecu and tested the voltages as suggested by Daznkel. Pins 1-6 and 12-6 both had 12v on them. It sounds like my next step will be to pull out the sensors and test them. ( I might wait for better weather !).

thank you both for your information

John