Hello everyone,
Just wanted to write the finishing post for this thread, now well over a year later.
After checking all of what I would regard as "basics" - stuff that doesn't involve completely ripping into the ABS system and getting brake fluid everywhere - such as sensors, ecus, wiring, switches, accumulators and finally the pump. It finally came time to try the one remaining piece of the system.... The ABS Modulator block.
I can report that this morning I was able to successfully remove the old block from the car, install a good one from my parts vehicle and bleed the whole system.
Thankfully, just after a quick test down the drive, I no longer get an instant ABS failure and Traction Fault the second I turn to ignition 2 - Instead it now does its proper self checks, leaves the abs light on until 5mph and then turns off... The entire system is working!
Feels amazing, for the first time since buying this vehicle 3 years ago - this is the first time I have had all of the bulbs installed behind the instrument cluster in the dash and had them all successfully extinguish themselves with no faults present.
I have a feeling I might be back again in the future, this time with a new thread, as I have yet to test this properly on the road for an extended period of time. At least this time, it might be one of the simple fixes, rather than replacing the entire core that the abs system is designed around.
So to anyone out there who is experiencing instant ABS fault and Traction Failure messages on the dash, and has tried all the easy stuff. I highly recommend you get a known good modulator and test it like I did in one of my earlier messages from April - simply unplug the big multiplug from the side of your existing modulator, then place the new modulator loose inside your engine bay with the plug installed into it. Then if you turn on the ignition and get no faults, bingo - modulator is at fault.
Another easy way to find out if its the modulator is if you have a capable scanner, I have had success with the Autel Maxidiag but ended up buying a Nanocom for doing things like EAS when I eventually get around the reinstating the system.
You are able to individually test the valves inside the modulator using a Nanocom, it has a little test that fires all of them individually. For me, my rear left and right valves made no clicking noise when being tested - hence they were either stuck or had a bad ground.
I feel as these vehicles get older only more of them will start the experience this issue, hopefully what's been written here will get picked up on google search results so more people will be able to fix their P38s. Without having all these years and years of threads to read through, there's no way I would have been able to diagnose and eventually fix the vehicle to this degree.
Thanks to everyone who still stays active on these forums, they are kind of an ancient source of information at this stage but certainly the best when it comes to knowledge, experience and passion for the cars.
View attachment 289867
My modulator collection right before installation.
Dashboard with zero faults, 232K with no warning lights is pretty impressive! Id like to see a L460 get to that mileage with no issues! Everything fixed with common hand tools and a good diagnostic computer.
