Front Bumper Project Gone Wrong

[Righteousness]

Hey all,

I handed in my 2015 Volkswagen Sportswagen TDI SEL (White - LC9A) to a local auto-body shop for a personal project. I decided that I wanted to have the MK7 GTD Sportswagen style so I committed myself into purchasing a genuine GTI front bumper alongside, GTD grille and other appropriate parts to match the replication of a GTD model which was not offered here in Australia

Issue 1: [RESOLVED] After my car being at the shop for a week, I came to collect my car and instantly noticed the front bumper hue was mismatched and appeared 'blue' in the white: https://imgur.com/gallery/WjWFJiA

(It was more noticeable in person).

Issue 2: [UNRESOLVED] On top of this, the front parking sensors were detecting objects in front whereas there was nothing to detect except the road in which it drives on. The sensors in the front don't work correctly but the outside sensors work fine. The interesting part is that the sensors do not detect anything whilst the car is on a light coloured road but when I enter onto the main road (black asphalt) the sensors experience a nervous breakdown. I have cleansed the sensors and there has been no difference. The workshop mechanically heated my old parking sensor brackets into the new bumper and they made a statement, "The old parking sensor brackets do not correspond with the new bumper so we'll need to order in the correct parking sensor brackets". This made me upset as this was a 'guess' and added to the cost of the bumper cost...

The auto-body shop firstly repainted the front bumper again to the correct match (the auto-body shop utilised my side mirror caps to colour match - big mistake prior as the side mirror caps were manufactured in another country as opposed to the body of the car! They don't properly match the bumper whether plastic or metal). The parking sensors still display the same results as before although the paint match is immaculate.



Speculation: Is the sensor not flush with the bar? Is the sensor angled too far down? Was the wiring harness damaged during removal and installation? Are sensors allowed to be resprayed, if so, is the resprayed sensors interfering with the proximity? Is the bumper causing the issue? (Manager deterred to this issue although I doubt this as it's interchangeable and no one else has experienced this issue before). Have the brackets been welded incorrectly to the bumper?

I am looking forward to anyone who has answers, cheers!

[Righteousness]

Anybody got anything? Feel free to ask your mate if you’ve got not idea, lol.

[DV52]

@Righteousness: Hi. wow - you must have liked the look of the GTD a lot!!!

I'm just guessing (emphasis on "guess"), but since this is a not-common retrofit, I would suggest more information gathering is needed. If this was my car, I would start my data accumulation by hooking-up a diagnostic cable to the vehicle - and looking at what the car's CAN network says about the sensors. The mk7 has a quite sophisticated error handling facility that can be very instructive in chasing these types of "odd behaviors"

Anyway- the proximity sensor operations are intimately tied to the car's CAN network and the car itself has the ability to provide valuable information towards diagnosing the problem. Seems illogical not to use the facility (no offense intended)!!

I suspect that you might not own a diagnostic cable -if so, this forum has a "pimping-facility" whereby members can ask for help from others that own such devices - see HERE

Don

[Righteousness]

Hi Don,

Thank you for the response. I have a VCDS scan tool already. I scanned it and I don’t think I had anything related to the sensors show. There wouldn’t be an error for this would there?

[Righteousness]

I spent more time looking further into this. I'm glad I was wrong. I've noticed also Don that you're a great problem solver whilst jumping across different websites!

Here's some code:

Address 10: Park/Steer Assist Labels: 5Q0-919-294.clbControl Module Part Number: 5Q0 919 294 E HW: 5Q0 919 294 A
Component and/or Version: PARKHILFE 8K H03 0048
Software Coding: 0031151011
Work Shop Code: WSC 00028 028 00067
ASAM Dataset: EV_EPHVA18AU3700000 002024 (VW37)
ROD: EV_EPHVA18AU3700000_002_VW37.rod
VCID: BD2CD38EADFD92130C7-80E8
1 Fault Found:


1113107 - Front Parking Aid Sensor(s)
B10FC 13 [008] - Open Circuit
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 3
Fault Frequency: 1
Reset counter: 132
Mileage: 32220 km
Date: 2021.11.16
Time: 14:42:56

[DV52]

@righteousness: haha- not quite sure that you are correct - better to say that I attempt to problem solve (often unsuccessfully-alas)!!

So, the DTC in your scan tells the following story:

• Fault first registered on 16th Nov 2021 @ about 2:42 PM (maybe an earlier version of this fault was cleared before this date/time?). The nature of the error has been confirmed as being "intermittent" and in the intervening period since first registration and the date of the auto-scan (?), the error hasn't reappeared in a subsequent ignition cycle (Fault Frequency=1)

Intermittent faults are a bitch to trace because of their transient nature. But, clearly the module is saying that somewhere between the module connector and one (or more) for the front sensors, there is an occasional break in the wire/connectors. The fact that the DTC doesn't identify a particular sensor suggests that the fault is common to all sensors - but this is a guess!!

Given the probable "common-nature" of the DTC, maybe start at the coupling point; you should be able to trace the wiring loom for the sensors back to a single coupling point in the engine bay - check the pins at this coupling point.

Each of these sensors (not sure - maybe, 8 x sensors on your car?) is a 3 x pin device and they share a common power supply on two of these pins. So you should be able to measure battery volts on 2 x pins using a multi-meter on each sensor. Check ALL connections are tight and that there are no bent/broken pins in connectors

Don

[Righteousness]

Evening Don,

Thank you for that depth of information! I plan to see Volkswagen soon so they can diagnose it and properly give a diagnosis on the situation so the independent auto-body shop can be faulted which I believe to be true. Their workload appears to be hefty and that can be mean a fast pace installation. They have blamed the bumper but how can that be faulted?

[Hillbilly]

Evening Don,

Thank you for that depth of information! I plan to see Volkswagen soon so they can diagnose it and properly give a diagnosis on the situation so the independent auto-body shop can be faulted which I believe to be true. Their workload appears to be hefty and that can be mean a fast pace installation. They have blamed the bumper but how can that be faulted?

Perhaps because as you said they had to reposition the sensor mounts and they may not be done properly