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I should be doing any number of things for my employer, but I think it'd be more fun to post here.
The following is taken from what appears to be a BMW document, titled "E46 Traction and Stability Control Systems".
I'm posting it here because there are so many damn features in the Mk60 system that the acronyms become annoying.
The Teves MK60 system is designed to maintain the vehicles stability during:
ABS braking regulation
ASC+T traction control
DSC for oversteer and understeer control
Additional features are also programmed into the control module to enhance driver safety and comfort. These features are:
CBC - Corner Brake Control
EBV - Electronic Brake Proportioning
MSR - Engine Drag Torque Regulation
ADB - Automatic Differential Brake
DBS - Dynamic Brake System - comprised of
DBC - Dynamic Brake Control
MBC - Maximum Brake Control
It's clear to me that I only want ABS and its sub-functions. The sub-functions are described thusly:
Corner Brake Control (CBC)
CBC can occur if the vehicle is cornering and ABS regulation is not taking place.
If the control unit detects transverse acceleration in excess of 0.6g and the brakes are applied, CBC prevents a build up in brake pressure to the inside rear wheel. This prevents the vehicle from entering into an unstable situation that can lead to Oversteer.
The MK60 accomplishes this by closing the Inlet Valve, thus not allowing brake pressure to increase at the brake caliper.
The difference in braking force between the two rear wheels creates a yaw force that opposes the oversteer and allows the vehicle to handle neutrally.
Electronic Brake Force Distribution (EBV)
EBV will adjust brake pressure to the rear axle based on the rate of slow-down of the rear wheels, ensuring even brake force between the front and the rear of the vehicle.
The control unit monitors the wheel speed when the brakes are applied and compares the deceleration of the front and rear axle to determine required regulation.
If the vehicle is moderately to fully loaded, the rear axle will take longer to slow down, rear wheel brakes can then be applied at a higher pressure .
If a vehicle was lightly loaded, a similar brake pressure would be too great and result in an unstable situation.
Regarding CBC, at first I was concerned that this might have a negative effect on trail-braking, but from reading this passage, it seems like CBC would only step in if the brakes were not already applied, the car was experiencing +0.6g of lateral force, and the driver then applied the brakes. I'm no track wizard, but I can't think of any time I would want to apply brakes at +0.6g lateral force in a turn. Seems like a "save the underwear" feature to me.
I think it's worth noting here that EBV does not substitute for static brake proportioning on the BMW. In the BMW master cylinder, there are two different sized pistons (to my knowledge). So the proportioning is done inside the master, before the pressure sensors. I've put included a brake proportioning valve placed before the pressure sensors for this reason.
Some other relevant gems from this document:
The brake fluid level switch is incorporated into the cap. The switch is a reed contact switch. If the brake fluid is at a sufficient level, the switch is closed and switched to ground.
If the fluid level drops below a specified level , the reed contacts open and the MK 60 responds by switching off the ASC/DSC functions.
Normal braking and ABS operation is unaffected.
Having re-read this now as I was writing this post, I think I'm going to remove the wire I tied to ground for this pin, to ensure that the MK60 doesn't try and do any ASC/DSC functions. From my reading (not cited), I believe that without the steering angle sensor and without communication with the engine computer, it won't try those things, but I don't have anything in my hands to verify that.
Brake Pressure Sensors
The sensor provides the control unit with an analog signal proportional to brake pressure. Voltage increases with increasing brake pressure.
Plausibility with BLS (brake light switch)
The signal input from the brake light switch is compared with the pressure sensor values.
The pressure sensors must not detect more than 5 bar when the BLS is not actuated.
Both signals are used to form a redundant BLS input which is constantly monitored.
Short version - you may not actually need a brake light switch, but it's probably a good idea to have it working. Note that the switch wiring pretty wonky (and something I messed up and need to fix). The wire for the brake lights should be grounded, unless the brakes are on. This seems like an odd choice of logic to me, but I don't design circuits for a living.
Originally Posted by 3DMMotorsports
Brake Light Switch: The MK60 requires an input when the brake pedal is depressed. The wire that senses this needs to see a chassis ground when pedal is NOT pressed (Normally Closed) and open circuit when the pedal IS pressed.
Last edited by thebeerbaron; 05-26-2020 at 04:41 PM.
Reason: Editing for scanability
I'm done plumbing the system and actually have the car running and driving and stopping. I have not been able to really test the ABS function...
I chose to put everything on the driver's side, where the stock intake sat. In the "E46 Traction and Stability Control Systems" document, it says:
The pre-charge pump used on previous systems is no longer required. Rapid pressure build up is possible because of the close proximity of the hydraulic unit to the master cylinder and improvements in the design of the return pump.
. This seems like a fine reason to keep the run between the master and the hydraulic unit. This also reduces the number of tubes crossing over the transmission - I only used the existing stock lines.
The E46s I found in the junk yard mount the MK60 at an angle. Maybe it's a good way to angle the ports so there's always somewhere for air bubbles to travel upwards and out of the unit. I went ahead and mounted the unit at a similar angle.
I mounted the BrakeQuip tees to a piece of bent aluminum to keep them from flopping all over the place. I placed the pressure sensors at the bottom of the tee so that air bubbles don't get trapped in the sensor. I'm hoping it also serves as a shield against heat from the header - apparently these sensors don't like excess heat. The Wilwood prop valve fits nicely underneath the master here.
I mounted the OBD port I pulled off a junker near the hydraulic unit. It wasn't the greatest idea as the BMW procedure for bleeding the pressure requires you to both use the PC software and press the pedal. The cable I used wasn't long enough to reach, so I had to dig out an old USB extender. Not a big deal, but don't make this mistake.
I've now lost the ability to organize thoughts into a cogent post. More later.
Last edited by thebeerbaron; 05-26-2020 at 04:43 PM.
Reason: Add title/subheading for scanability
I took it out at Thunderhill West for a track day with TrackTime (who I think ran a great day). It was six 20-minute sessions on the 2-mile track. I was in the Advanced group with a bunch of faster cars, so I had no one holding me back. I have stock 1.8 brakes with GLock R10 fronts and R8 rears. I did two sessions on older 205 RE-71Rs on 15x7s and the other four on brand new 225 RS4s on 15x9s. I didn't futz with the ABS module at all.
Observations:
You can still lock up a wheel if you're completely ham-fisted in a braking zone.
You can definitely feel the system working when you hit a bump under braking and you lose traction in an individual wheel.
I did not feel the system fight me or do anything I wouldn't want it to do. There were a couple times where I turned the wheel while braking and it did not get confused or try and make me go straight. I don't mean to say I was trail-braking, I was just being stupid and turning in before I was really going slow enough to do so.
I don't generally trail-brake, so I have no results to share on that.
The feedback through the pedal was not disruptive. Yes, it'll do that ABS-pulse thing, but it only seems to do that when you've really working it.
If you're not familiar with your car's braking capabilities, it might actually be a bit dangerous: your foot is all the way to the floor, your tires aren't locked and are perfectly silent, you're not slowing down as much as you thought you could...and you end up in the grass/wall/pond/parking-lot. You all know I'm a dumb-***, so I'll admit that this happened to me in the first session after I threw on the new tires. I went into the dirt, no big deal. Lesson learned.
You can spend a lot less mental effort in your braking zones. Get on the brakes and wait to turn in. I'm guessing this will, eventually, increase my repeatability for any given corner.
I didn't get my data capture set up for this event, but based on the fact I'm nowhere near as good a driver as most of you on here, I'm driving a non-turbo Miata on FM Foxes instead of the requisite Xidas, and my car setup is probably lacking, what data would you find helpful for me to capture the next time I'm out?
After hearing your observations, i'm beginning to wonder how much an improvement this system is over the NB2 ABS. Does anyone have any thoughts on this? The NB2 system is way easier to retrofit, cheaper, and if only marginally less performance, im not sure this is worth the $ and effort.
After hearing your observations, i'm beginning to wonder how much an improvement this system is over the NB2 ABS. Does anyone have any thoughts on this? The NB2 system is way easier to retrofit, cheaper, and if only marginally less performance, im not sure this is worth the $ and effort.
No Comparison, you will throw rocks at the NB2 system once you have driven both.
Does anyone know of a solution to convert the active BMW sensor signal into a passive type? I've seen things to do the opposite but not for this. I have a Race Logic TC which uses passive sensors so I'm trying to find a way to use the BMW sensors with it. Otherwise I guess I'll have to go NB2 if I want to stick with the RLTC.
At a track day, looking for some input. I keep getting a 5E24 code, “Pressure Sensor 1/2 Not Plausible”. I clear it and it comes back the next session. Anyone have a clue on what to look at? Thanks in advance.
Medium - "Receptacle, 1.5mm". These are female contacts used in the large 47-pin connector for the control module. The TE part number I used is 1355556-1. I bought mine from Mouser - $0.129 each.
Seals - For the small and medium connectors, I used TE part number 967067-1. They worked OK, not great. I think the issue was my crimping. I do not have the proper tool (see below). I bought mine from Mouser - $0.146 each.
The seals didn't work great for the 47pin plug because you used the wrong MQS contacts. 1355556-1 is to be used without those seals.
The proper TE contact to accommodate the seal is part number 1241603-1
The TE part number for the seals are:
For 22awg wires 967067-2 (yellow color)
For 18-20awg wires 967067-1 (green color)
Blanking seal: 967056-1 (blue color)
Does anyone know of a solution to convert the active BMW sensor signal into a passive type? I've seen things to do the opposite but not for this. I have a Race Logic TC which uses passive sensors so I'm trying to find a way to use the BMW sensors with it. Otherwise I guess I'll have to go NB2 if I want to stick with the RLTC.
The ABS pump has outputs for the 4 wheels (at least the MK60E5 one has) but the case should be the same with the MK60. The ABS unit grounds the output on every tooth pulse, so you use a pullup resistor to either 5V or 12V (or any other) to generate a square wave amplitude what your Race Logic TC expects to see
The seals didn't work great for the 47pin plug because you used the wrong MQS contacts. 1355556-1 is to be used without those seals.
The proper TE contact to accommodate the seal is part number 1241603-1
The TE part number for the seals are:
For 22awg wires 967067-2 (yellow color)
For 18-20awg wires 967067-1 (green color)
Blanking seal: 967056-1 (blue color)
Thank you for that. I was just wondering the other day what is the correct connector for seals because I got the same thing and notice if they were too short. Question for you though, What is a good tool to crimp the seal for that size? I have several tools with the circular crimp on them for seals but they were all too big for this one.
The ABS pump has outputs for the 4 wheels (at least the MK60E5 one has) but the case should be the same with the MK60. The ABS unit grounds the output on every tooth pulse, so you use a pullup resistor to either 5V or 12V (or any other) to generate a square wave amplitude what your Race Logic TC expects to see
Doug Wardell‘s harness as an option to get the analog outputs for wheel speeds from each of the four sensors.. You could use that to feed the RLTC I think since they are coming out of the harness as an analog signal
Thank you for that. I was just wondering the other day what is the correct connector for seals because I got the same thing and notice if they were too short. Question for you though, What is a good tool to crimp the seal for that size? I have several tools with the circular crimp on them for seals but they were all too big for this one.
The proper crimper for these contacts is TE part number 539635-1 with die 539693-2. It's expensive though. I'll try find if there is still a third party one which can do the job.
Which m10 are bubble? I thought the pressure sensors screw into the BQ44 adapter?
I believe all four outputs from the ABS module are M10 bubble. The two inputs may be M12 bubble. That sounds right - I'm not in front of my car right now.
All the Miata stuff is M10 inverted flare.
Regarding the mill work - I'm afraid I've got too many projects going on right now to help you out. You should see the lack of progress on my K-swap!
I believe all four outputs from the ABS module are M10 bubble. The two inputs may be M12 bubble. That sounds right - I'm not in front of my car right now.
I'm pretty sure there are 4 M12x1 Bubble flare and 2 M10x1 Bubble flare ports in the module, it's only the right hand front and rear outputs that are M10.
You also need to use long thread brake flare nuts in the module, the short ones run out of thread before the pipe seats, found this out the hard way.
The pressure sensors use an M12x1 inverted flare and yes the BQ44 adaptor is the right one for this.
05-11-2020, 10:14 PM
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