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21 Turbo 2WD R21 Turbo ABS Question (Alpine A610 related)

r5gordini

Well-Known Member
Not really asking this for the sake of the R21 - just trying to diagnose my Alpine A610!
Just a question - if you jack up a 2WD R21 Turbo and run the engine with it in gear, so that the front wheels are turning, does the ABS light come on?
Just want to compare the behaviour with what I am seeing in the A610. And no, I don't get the ABS warning light if I run the A610 wheels in the air.
No idea if the systems are similar or not!
Symptom with the A610 is that the warning light works properly as in it comes on when I turn the ignition on, then extinguishes when the engine is running. Just no functioning ABS :-(
 
are you sure the abs light isn't wired to another indication light and there is really an issue with the abs?
Normally the light comes on and blinks with a fault code if its not working
 
You know, I was thinking the same as I wrote it! To my knowledge, it only blinks if two pins are shorted in the diag socket but I have no idea whether the same applies to the A610 as it does to my Quadra. Solved my Quadra's problem by using that method - short the pins, then count the blinks. There's nothing in the A610 manual that talks about diag codes for the computer (even the Renault original manual). Could be worth a try but I have no idea what the pins are and whether they are the same! I might give it a go.
But yes, I am pretty sure the warning light is connected to the ABS. If I disconnect a specific ABS relay, the light illuminates.
 
I have no idea whether the same applies to the A610 as it does to my Quadra.
It does not. Only the Quadra has self-diagnosis, it's a very different system considering they look the same and even has a 5th sensor on top of the transmission tunnel for sensing lateral G force. The whole system save the brake calipers and front brake lines is quadra specific. Master, Computer, Wiring loom, all of it.
 
Yes - the A610 has the same sensor!
Does the A610 have the same electronic brake system that the 21 does? ie, no servo, electronic accumulator? Or does it have a servo?
It has a more conventional system. A servo. So presume the whole setup is different. I was hoping to maybe try my Quadra computer in my A610! But I think that's a silly idea... I was going to look at pinouts and part numbers before just whacking it in there and potentially blowing something up though!
 
Yep! Definitely a silly idea. Could end up with two non-working cars instead of just the one!
Master cylinder is buried underneath the car under a shield! Not easy to get to but I assure you it's standard as they come. I will post photos of the bits I can get to easily.
It's an interesting one as the Alpine club doesn't have much idea what to do to properly fix the issue. Apparently none of the A610s (apart from the very early ones) works!
And yes, those are the symptoms. Light comes on when the ignition is switched on. Goes off as soon as the car is started. Stays off, never comes on again. Wheels lock if I brake hard enough! Well... I say wheels, but it always seems to be the left front. Probably coincidental.
I have got full troubleshooting instructions in the manual but they are confusing to say the least and always refer to the Bournier thingy... Yeah, right!
 
The most common cause I came across on A610 for non working ABS was the heat fuse in the white relay blowing due to various issues with the main wiring to the valve block (60amp wiring)
I will take a picture later
Also if the Abs is working I found that the system didn't detect a sensor issue until at least 15 mph for couple of minutes was done, plus the trigger point for activation seemed higher than you would normally expect especially if comparing with modern cars.
 
Thanks! I have checked the fuse in the white relay. It is fine, presuming it's the one and only fuse in there!

All interesting stuff. I drove for quite a while before testing it. Braked hard at 30-40mph. Want to try wet grass at some point!

There's another potential clue in that it looks like there were once earth wires attached to the front hub carriers but the wires are now absent.

Sent from my HTC One_M8 using Tapatalk
 
The ABS system didn't have any earth wires on the hubs only the inductive sensors, so they may be remains of pad warning wires.
If you got access to an oscilloscope check the sensor pattern at the ECU connector to see if they are all the same pattern.
In the meantime I will dig out my repair manual and refresh myself with the system.
 
Ok! Thanks. There did appear to be earth wires attached to the stub axle carriers at one point as there are connectors on both sides. I'll see if I can take some photos.

Yes, I have an oscilloscope. Will check the sensor patterns.

I don't want to get too distracted from the fuel computer project either, but the A610 was broken so it got me starting to wonder...

Sent from my HTC One_M8 using Tapatalk
 
Oh and on that note, I have done a tiny bit on it in order to try to read fuel pulses. Will let you know how it goes. I know it's academic for you but I do want to solve it so it works for both OE and standalone

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