W208 Parktronic PTS Fault

[BenzRule]

Good afternoon members,

I have been trying for months to get an issue solved for my father and multiple garages and diagnostic reports have confused us no end.

Reaching out to you good folk in the hope someone has the experience none of the Benz specialists I use has to solve what is in essence a simple query.

The issue:

Dad's W208 convertible has front and rear factory fit parking sensors. They stopped working. Had it diagnosed and it was :

Control Module N62 Faulty

Ordered a spare 2nd hand module, being told its plug and play and the part numbers matched. Did not work, so had it diagnosed and all 10 sensors and the module say:

A43b10 (Left outer sensor, rear bumper) :The plug connection has poor contact or is loose, or the sensor or cable is faulty. This fault is recorded for each sensor.

and

Control Module N62 Faulty

Went back to the seller who assures me it needs coding.

Had the code data from the old data copied it said successful, but the issue remains.

We clear the fault and it returns. I expected that.

Got a 2nd unit and the issue is the same.

I know these are prown to water ingress from the front water drain, so it could be both units are faulty but to save my sanity I have two questions of your members:

1) does the Parktronic control module need to be coded and if the original is faulty as in my case how can its data be copied to the replacement? The process claims successfull but my inquisitive mind wants to understand how

2) do you need Xentry to successfully code or will any decent high end system do the job?

We have tried 4 diagnostic systems and all have the same outcome. A walk test (actuation I think it's called) shows the internal displays working but no graph data from the sensors front or back.

Could it be wiring loom damage? If so surely the coms would not run, diagnose, clear and then re-find the fault.

I'm at a loss. We could do without sensors but dad is 81 and has a tight parking spot. Dont want to trouble him unduly.

Hoping someone can help as I am out-of ideas.

The vehicle is a w208 320 with the AMG 430 body kit from factory. She's old but we love her.

Thanks in advance.

Raj and Dad

 

[noogieman]

You might have to take the rear bumper off and look for the problem.

 

[BenzRule]

You might have to take the rear bumper off and look for the problem.

Did that when we traced each of the 10 sensors manually for corrosion etc.

Today to make matters worse :

Main Dealer tells me the Parktronic is a one time coding unit and cannot be swapped between vehicles!

An independent tell me, they are plug and play and he's done a dozen over the years. No coding at all required.

Another independent tells me his lead technician agrees they are one time coded from MBenz but can with time and effort be coded to the doner car.

Me, I'm confused and exhausted. Could be I have two damaged units. Sheer bad luck.

I was hoping someone on here had swapped one and knew the answer. Will wait a little longer in the hope they have.

 

[noogieman]

These toys are fun to have on a luxury car but when they start to fail they give you nothing but headache!
Have you checked for blown fuse and possible broken relay ?
You have to start check everything before spending money on parts.

Dealerships has no clue about older cars, their technicians mostly work on newer cars and have very little knowledge about classics.

 

[BenzRule]

These toys are fun to have on a luxury car but when they start to fail they give you nothing but headache!
Have you checked for blown fuse and possible broken relay ?
You have to start check everything before spending money on parts.

Dealerships has no clue about older cars, their technicians mostly work on newer cars and have very little knowledge about classics.

Thanks for taking the time to reply

Blown fuse ruled out else the replacement or original parktronic unit would not communicate or be recognised by the diagnostic kit. Relay, I suspect the same as the actuation tests all pass.

What's thrown me is one garage saying they have plug and play swapped many out, and another saying they are coded to the car by MB and are therefore hardcoded with no option to copy the data over and code.

I work in IT and find these problems intriguing and bet this one is going to be simple when solved.

My wife is very happy as now she thinks I will sell the car, especially as Mr Khan the London mayor is extending the ULEZ to outer London in August. This vehicle did 500 miles or so last year and will do the same this year so scraping her or selling to a Northerner when we have had her for 17 years feels wrong. Give a bloke a little summer fun.

If I find the answer I will share it here and if anyone else has experience of swapping a unit out they could save me a lot of time.

On the plus side mortgage rates are slowly dropping each week

 

[noogieman]

This is what you had done so far to fix the problems but didn't help?

Scan codes - clearing codes resulted in no fix.
Dismantling front and rear bumper checking wires and each sensor resulted in no fix.
Buying a 2nd hand PTS relay resulted in no fix.
Checking for blown fuse in engine compartment - found no issue
Checking relays in the fuse box in engine compartment - found no issue

You must have noticed if critters had chewed on wireloom shorting the PTS system?

Must be one of the PTS modules giving up or possibly some of the sensor(s) acting up?

 

[BenzRule]

Indeed I have checked for squirrel or rodent damage, as have I checked every sensor when I cleaned them one by one

One thing I have wondered is if the diagnostic kit can see the parktronic module is it actually the loom that has an issue. Usually when a sensor goes the same symptoms are given: red bars and beep and then PS switch lights red and they go off. So if the loom was bad it may do likewise, but then surely the error would be sensor related not module. Driving me nuts as you can see. A new diagnostic image attached.

No reply from the main dealer after 3 calls to answer two questions:

1) New Parktronic module cost
2) Does it need coding and at what cost

They said they will get back to me. Won't hold my breath.

But I will solve this eventually as my mind is set on establishing what the truth is:

1) one time coding from MB
2) possible to recode
3) plug and play part swap

Will save someone else the trouble when I post the answer as its the same module used in the E and C class I am told, so not a CLK only issue.

3 days till the weekend

 

[MSinghMerc]

Hello Raja, did you solve the issue in the end?

 

[BenzRule]

Hello Raja, did you solve the issue in the end?

Morning,

Unfortunately not yet.

I am having the wiring loom traced (sensor side) from Parktronic Module connector to all 10 sensors. Probably at the weekend. Will update on what they conclude.

 

[noogieman]

I hope my PTS don't screw up?

If 12V doesn't activate PTS module when you turn the ignition ON then it's most likely fried?

 

[andy27168]

Hi
The control unit on a 208 doesnt need coding, and is plug and play. If the car never had it fitted when new and it was retro fitted then the car not the control unit would need coding and my understanding of this era MBs was the coding was only to tell the diagnostic to look for the control unit to scan it.
I am almost 100% you have a damaged loom.
If it was mine check for damage at the main plug behind the bumpers for each of the looms, liberally spraying with contact cleaner.
Also try reading the codes with each loom disconnected in turn, noting any different behaviour in the display lights.

 

[Jobsworth]

Are you 100% sure the part numbers match? Variations in part number have the sensors wired to different pins. May also be worth checking with Mercedes parts what the correct part number for the car is. I suppose it isn’t beyond the realms of possibility that the part has been swapped before and the outer case isn’t matching the circuit board within. You might be able to plug your original unit in and read the part number from the diagnostic machine, just to check it matches.

 

[MSinghMerc]

the PTS is right pain, on my W204, the Mercedes diagnostic also said its hte white pst moduel behild the passenger footwell, i ordeere the 3rds one, and it still ha snot fixed the problem, so will have to check the loom and the sensors, sma ethign with my w208.

 

[BenzRule]

Hi
The control unit on a 208 doesnt need coding, and is plug and play. If the car never had it fitted when new and it was retro fitted then the car not the control unit would need coding and my understanding of this era MBs was the coding was only to tell the diagnostic to look for the control unit to scan it.
I am almost 100% you have a damaged loom.
If it was mine check for damage at the main plug behind the bumpers for each of the looms, liberally spraying with contact cleaner.
Also try reading the codes with each loom disconnected in turn, noting any different behaviour in the display lights.

Thank you Andy

Apologies for not replying but for some reason I never got any emails for the last three responses.

No one would confirm that they do not need coding, but I was sure it had to be the case. Now I have 5 control units and none work. All matching part numbers. All from a similar age and model. All claimed to be from a working doner vehicle.

Whilst I have removed the sensors (all 10) front and rear and checked for damage (none found) and sprayed and cleaned and reseated, no joy. I will now try tracing the loom from PTS module to front and rear bumper.

What gets me is that I can run the actuation test that turns the two front and single rear displays on and off, but not the 10 sensor test via the diagnostic hardware. But I suspect the loom has two parts:

1) Power and Displays
2) Sensors

All points to the sensor loom.

Will be a fun afternoon but It's worth it for the love we all have for our baby benz beauties.

Mr Khan the Mayor just emailed me to say scrappage price £2000. No thank you. I would rather pay £12.50 each trip and use her in the summer months. £500 a year and she's as reliable and still turns heads.

Thanks for the pointer and your time

 

[BenzRule]

Are you 100% sure the part numbers match? Variations in part number have the sensors wired to different pins. May also be worth checking with Mercedes parts what the correct part number for the car is. I suppose it isn’t beyond the realms of possibility that the part has been swapped before and the outer case isn’t matching the circuit board within. You might be able to plug your original unit in and read the part number from the diagnostic machine, just to check it matches.

Hi Jobsworth ,

The system is factory fit and as the footwear and plate was secure I am 99.9% sure its not been replaced internally, leaving me with a red herring case and part number. Images attached of the ones I have. Quite a collection. Have also read the original part number and it correlates.

So the loom is my area of focus. No rain today so we shall see if my persistence and your help (everyone) pays off.

Wish me luck.

Cheers,

Raj

 

[BenzRule]

the PTS is right pain, on my W204, the Mercedes diagnostic also said its hte white pst moduel behild the passenger footwell, i ordeere the 3rds one, and it still ha snot fixed the problem, so will have to check the loom and the sensors, sma ethign with my w208.

I feel your pain Mr Singh ...... don't give up!