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the crazy wheel speed sensor you're showing should pull a code + ABS light On.
The way none of this is happening means the ABS/ESP wants your attention.
It's weird that the shifter is involved in messing that up... The CAN bus out of ABS must be disrupted... so unplug ABS and see what happens to crazy speeds. Normalized ?
++++ EDIT++++
Small world @KT landed on the same module
Visualy inspect connector male/female
Clean nearby GND screw(s)
Check F-SAM fuses collection
ABS/ESP VIP must get alive on bus scan - No alternative choice to that!
🤞
Last edited by CaliBenzDriver; 08-30-2022 at 06:10 PM.
Thank you, CaliBenzDriver and konigstiger. When I last posted, I expected to have some time within couple of days to measure speedsensors and stuff. Well, within couple of days I got sick, and couldn't do anything! And still sick, but now with medications (wasn't just regular flu).
Anyway, I know that I have two grounds and two positives on the module connector (one from the passenger footwell and other from the drivers SAM). There's also ABS light present on the cluster, but zero codes about wheel sensors. Pull the fuse, pull the connector, I loose connection with the module.
When konigstiger sent those pdf-files, I quickly went through them with my phone, and really didn't read the function description of the ESP control unit. Yesterday I had my laptop open, and paid more attention to that particular pdf file.
I was puzzled as why the shifter position would affect the speed reading of the sensors. Well, turns out the ESP module needs to know which gear the transmission has, to be able to control the brakes correctly. Also, found out the front wheels play the most important role on the whole brake ansd stability program. That's why they show "stationary" speed, but rears don't. Still, why they show speed, and insane speed that is, when the car is not moving?
Yet another also, N47-5 needs torque value from the engine control unit via CAN message. What I just thought, is that even though to my understanding, ESP unit doesn't need to be paired with other modules when the part number is the same (It's the same, and acts the same like the old one), but does the ESP control unit expect to have certain CAN message from the engine control unit? The EM/ESL/EIS combo that I bought last year, naturally has different vin number. I just run it to a lastvin, and noticed that donor car had a SBC brakes, mine doesn't. Could that be the issue that ESP unit doesn't understand the message that comes from the engine management? Probably not. But just for giggles I could plug the old engine control unit and see what happens (I know it won't start).
Scanner connects to the ESP unit, but all the CAN messages don't go through from the other modules. Something is wonky with the CAN.
I had read through that ESP installation, but completely overlooked the STAR section. I figured that since the scanner was showing exact same with either of the ESP units, there's something wrong elsewhere.
Like the rear suspension module. Before I changed the EM/EIS/ESL, I overrode relays to see if I get anything to wake up. Chassis relay overridden, I got rear suspension to raise to the correct height, so I thought good, at least that's working. Well, it doesn't. Bought another, does not work. There is positive, negative, CAN bus... but scanner does not find it, and cluster says malfunction on suspension. But I'll dig deeper to that after I get brakes to work.
But I'll ask from my co-worker if his friend has time to come over and check out my car with STAR next week, we'll see what happens. I should've asked him on May when I changed the ESP unit, but I was bummed that it didn't work so I lost motivation to do anything with it. I have soo many unfinished projects, that it's hard to find time to do them.
Don't beat yourself down, you've done and learned a gread deal with this project car.
What would really empower you is your own Xentry tool to diagnose activation faults. With out that you don't get the full picture and this slows down your progress 2nd guessing choices.
I've actually already looked the pricing of the Xentry, and maybe someday I'll have my own. It would make this project so much easier. On my day job I have my own diagnosis laptop, access to wiring diagram and all, so when I'm used to have all the needed tools to chase down electrical gremlins, it's really frustrating now that I have somewhat limited tooling. Though scanner has taken me a long way, and also information that I've gotten from here, I appreciate that very much!
But, there's still the same issue as before, different module didn't change anything. Now I'm wondering that is there some other module that I haven't noticed. Older W211's had a ABS module next to a front SAM, and ABS pump was a separate unit. My car has nothing else than a front SAM in the left rear corner of the engine bay.
I found out something weird, though. When the car is standing still, and I'm reading the speed sensors, notice the front leftt sensor. Shifter on park:
Shifter in reverse:
Shifter in neutral:
And shifter in drive:
Why does the sensor reading change in relation to the shifter position? Transmission module, neither shifter module has no codes, and both are working as should
Surprisingly I really haven't had time work with my car, too much everything. But today I had some spare time and manage to open the mystery of those weird speed sensor readings... When I choose the vehicle, there is a window that has three model years under W211; to 05/2005, 06/2005-05/2006 and 06/2006 forward. IIRC I chose to use 06/2005-05/2006 based on registration card. But today I tried 06/2006 forward, and it gave different brake system! No weird speed readings or anything else, then I took a little spin to see what it says about sensors. I can check gap, rotation, speed... all checks fine except for the front right which is in verge of having too much gap.
Motivation to work with this has been next to nothing. Even though my car has been buried under the snow constantly, there was a good opportunity to get it lifted, so I had good times making new rear brake lines!
Pedal feel is 8,5/10, there's still some air in the rear lines. But now I don't need to worry about that hack job I did earlier with the lines.
Today I fixed the front right sensor issue. Figured since the sensor reads the speed, I'll try with a new magnetic ring. And it worked, no more ABS light on the cluster! At least on the low speed, couldn't take it to the road. However, there was ever so slight play on the bearing, could the sensor be so sensitive that little play messes up the gap?
I really could use a wiring diagram for the rear self leveling suspension. I have two supposedly good, working control units, but neither of them actually works. Cluster says suspension malfunction, and iCarsoft can not connect to them.
Would like to check the wiring, to see if there is anything missing.
Thank you, konigstiger! Function description revealed that it's much more complex system than what I anticipated. Really didn't thought that door locks or key fob would have nothing to do with the rear suspension. I suspect that suspension control unit is not getting wake-up signal from the front SAM.
It's fun to learn how all the systems work, but also really frustrating when you try to get things to work and realize that problem may be multiple reasons for something not to work properly.
Apparently, if you keep the scanner constantly connected, some things do not reset themself. Like the steering angle sensor. Week ago I though to try keep the power on (battery connected) for a longer period of time. Previously I connected it only when I was working with the car, just because I didn't know when I have time or interest to work again so to prevent battery dying I disconnected it. And kept the scanner connected to an obd port because on my actual job I've seen that the more you connect/disconnect the obd connector, the more they get mangled, leading to poor connection.
Anyway, noticed when after the work I went to start the car, I had no ESP message or abs light on the cluster.
Currently there's just SRS light and engine malfunction light. SRS is because airbag module and EIS have mismatch VIN number, and engine malfunction because of catalytic converter soot content. Which shouldn't be an issue as the engine control unit is not the original unit, so I believe that when I go to drive it, it should regenerate and light goes off. Before the lightning strike there were no engine light.
There are bunch of messages, though. Pre-Safe message (which I think is connected to a SRS light), suspension malfunction, and one more which I can't remember now... Anyway, when I switch the lights on, I get more messages from the lights. Front parking lights are out, they just flashed occasionally, now they are fully dead. But rear light messages are odd, as all of them work, excluding the outer tail lights. But message says tail lamps and brake lamps are out, and back-up lamps are on (which they are not). But I think there's an issue with the rear SAM.
About the front parking lights, are these original?
I was looking for them from interwebs, but mostly found ones that are regular 5 watt bulbs.
Rear SAM is a 2nd hand part. IIRC it was the first module I bought when I started to dive into depths of the W211 eletrical mysteries. This is the original:
Sooo... Not looking forward to dismanteling it, it's the most annoying module to take apart. Front SAM is much nicer design. But prolly do that before I source another one.
Ok, got it. This is a replacement SAM ghosting your rear lights.
1-- Have you cleaned all your GND posts in the trunk ?
I have not. Last saturday I took out the left rear light to see if the bulb is burnt. It wasn't. I did see that there is bunch of ground wires next to a rear SAM, but didn't take any closer look. But I'll clean them when I pull the rear SAM.
Originally Posted by CaliBenzDriver
2-- Do you have a way to scope your CAN-B signals ?
Might be. If I have time tomorrow, and if I remember, I'll check if we tools for that at work.
Originally Posted by CaliBenzDriver
3-- Scope your tail light power lines (even without a schematic).
Will do.
Got temporary plates for wednesday so I can take a road test, to see how transmission and ESP work at higher speeds.
Road test went well, no other issues didn't appear than what I already knew. Except couldn't perform the regeneration as the the soot content is too high.
I had driven some 20 kilometers, when I looked to the left and saw something on a corner of my eye: drivers seat belt has ton of mold!! Didn't noticed it before, as the belt is clean for some 30-40 centimeters when you pull it out. First I though to just clean it, but since there is no communication with the right seat belt retractor, I sourced two used units.
Headlight height adjusting seems to kind of work. There's no communication with the left module, and right one has a code from the adjusting motor, and also a code from missing suspension module. But they both work, though left one has a slight delay.
But damn it was nice drive! Went down the road like a train, and the three features I just love worked like a charm: automatic transmission, cruise control, and automatic wipers!
Where exactly is the N71 (HRA) located? On a W211 Networking pdf file, on the cover page, there's an overview of location for the modules, and there the N71 looks to be located somewhere around the left side of the dash. Though that image may be deceiving, and it's actually under the center console. Anyway, I pulled the plastic under the steering column and looked up and behind the dash, and couldn't see any module there.
N71, like all the previous modules were, is dead. It's doing something with the leveling motors, but since the scanner does not find it, I'll just check the part number and buy replacement part.
Took me a hot minute to see that there's no voltage on pin 15. I had already checked the fuses, I knew that there are two and both are good. Just didn't know which pin should have voltage. Circuit 87 is down.
That was about all I could do, as I noticed the battery voltage was down, just around 10 volts. Took it out for charging, I'll get back to it on friday.
I had driven some 20 kilometers, when I looked to the left and saw something on a corner of my eye: drivers seat belt has ton of mold!! Didn't noticed it before, as the belt is clean for some 30-40 centimeters when you pull it out. First I though to just clean it, but since there is no communication with the right seat belt retractor, I sourced two used units.
Well, I'm dumb! I've tried to keep it so, that before I purchase any parts, I check the actual p/n from the part. Kind of forgot it when I was looking those retractors because the belts on most of them were black. Found the correct color and didn't pay any more attention to it. Got the parts today, took apart b-pillar and instantly saw that I have wrong parts!! At least I now have the correct number, and found the correct part from couple of places.
Originally Posted by Heguli
Headlight height adjusting seems to kind of work. There's no communication with the left module, and right one has a code from the adjusting motor, and also a code from missing suspension module. But they both work, though left one has a slight delay.
Originally Posted by Heguli
Where exactly is the N71 (HRA) located? On a W211 Networking pdf file, on the cover page, there's an overview of location for the modules, and there the N71 looks to be located somewhere around the left side of the dash. Though that image may be deceiving, and it's actually under the center console. Anyway, I pulled the plastic under the steering column and looked up and behind the dash, and couldn't see any module there. N71, like all the previous modules were, is dead. It's doing something with the leveling motors, but since the scanner does not find it, I'll just check the part number and buy replacement part.
While I was taking apart the b-pillar, I removed the passenger seat. To my surprise there was nothing besides the yaw rate sensor. Connected the scanner and pressed auto scan. No HRA, but instrument cluster was looking for it. There was also XALWA-R (A1648205326), which have had connection issues. Sometimes I can get into it, sometimes not. Today I lost connection twice, but manage to get to it. I thought it was just a xenon ballast, but when I went to view data, there was stepper motors etc. So do I have the N71, or does the XALWA deal everything concerning the xenon light adjusting?
08-30-2022, 05:37 PM
