ABS Operation . . . . . how??

[Brett]

Just wondering if anyone knows how the abs is powered and works. Only reason I ask is because I want a new more simple wiring loom with stand alone ecu. I'm just worried this will deactivate my abs which given its a road car, I would really like to keep. Any help would be great.

 

[Cold fusion]

Hi Brett,
I always thought that the ABS management system was a seperate box and only connected to the engine management if there traction control and ESP. When the Scorpio Granada first came out it had abs controlled by a seperat management system.


Nigel.

 

[Brett]

I'm hoping that is the case Nigel. It would make things much easier for me.

 

[hualpa_jo]

Check out the wiring diagram in chapter 38C of the TN 3681A. Nigel's right there's no direct connection to the ECU. Of course there's the speed signal going over 119 speed signal interface...
The ABS control unit is fully integrated on a PCB inside the hydraulic unit.

 

[Brett]

Excellent! This is what I was hoping for. My wiring guy said it should be fine but I wanted to double check before I start to remove the cars nervous system.

 

[Steve-V6-D61]

Abs unit sends a speed signal to the engine ecu for fueling information, then the signal is then sent on to the speedo on the dashboard.

So although the ABS ECU is a stand alone unit it does supply info to other ECU's and dashboard, I ran my old Clio v6 without a working ABS ECU unit for about 200 odd miles the car was much better when i fitted a replacement unit. presumably because the fueling was adjusted for speed as well as the other normal paramaters and the speedo then worked.

Cheers

Steve

 

[Brett]

Excellent info as usual Steve. This is to a degree what I thought. Ideally I would like to keep the original dials etc but after you saying that I'm dead sure I'll have to ditch them. So long as I can keep the ABS with a stand alone ECU, I'm happy. Stack dash it is then! Lol

 

[Spike]

Another issue with loosing the abs is the MOT situation, i know its not physically tested within the mot at the moment but is there any legislation that is looming that may alter your descision, the legislation for idiot lights (dash) is at the moment being introduced and the next step could be an ecu or vehicle interogaton as part of the mot.... dont burn all your bridges brett.

 

[Brett]

Yeah this was one of the reasons I thought it best to keep the ABS. The dash light issue is a problem though as I know they are enforcing that nowdays. However, could it fail if there isn't any? In a similar way I suppose that cars can will fail MOT's with bald spare wheel/tyres but not if there isn't one. The ecu will be unreadable to them aswell due to it not actually being there.

 

[hualpa_jo]

I don't know how it's handled in the UK abut here it would fail without ABS. They have a type certificate for every car they test. In there is all the information they need. Using the example of the braking system it says what types of brakes are used, how the braking circuits are split, presence of an ABS, details about the handbrake system and much more. So there is no way to pass with modifications unless the tester fails to check it which isn't very reliable though. And yes the ABS is physically tested here!