ABS removal

[mutley]

Well now that I seem to be left along, I've been promised that I won't be disappearing overseas again this year (heard that one before) so I can FINALLY get back to work on my poor neglected NSX.

SO, going on from my MoT fail last year, the ABS on my car has never worked, so rather than try and refurb/repair, I'm thinking of removing the ABS pump. My question is this : What will I have to remove so that the MoT would disregard ABS on my car, and is there anything needed to connect so that the brakes would work normally?

(History behind this: it never affected MoT in the past as the ABS light functioned normally even though the ABS didn't work, but now as I have the S2K dash in my car, the ABS light doesn't work hence the MoT failure on that point).


Anyone?

Cheers
Jim

Edit: corrected typo's

[britlude]

i'd double check with yr MOT station, i think there was mention of once having an ABS system, it must always have an ABS system...... so stop people removing them! there's been a few changes with the MOT coming in this year!

however, i think their check is just for the ABS light function...

have you shorted the pressure sensor connection to fool the ABS into thinking the pressure is there???? the ABS then thinks things are good to go!

[mutley]

It is very probably something to do with the wiring connections with the S2K dash kit. My other option, I was just doing to wire the ABS light to the Oil light, that way it will come on then go off as per the MoT checks.

[Kaz-kzukNA1]

Hi, Jim. Welcome back.

Could you elaborate on your comment, 'the ABS light doesn't work hence the MoT failure on that point' ?

MoT manual is very clear on failure condition with ABS light.

Does the ABS light never light up even during the bulb check mode?

Or, when you turn the IG key into P2 ON position, does the ABS light switch On immediately or does it light up after about 1 – 2sec? Does it stay On forever after this point?


Based on your post, it seems that even if the ABS itself didn't work, the ABS light operated properly with the classic ABS controller before S2K dash conversion.
Therefore, your issue is more of electronics I/F circuit so removing ABS may not change anything.

It all depends on the answers to my question above, but you may just need to reverse the logic.


Kaz

[mutley]

HI Kaz,

Yes it is more than likely to do with a wiring issue. But as my ABS has never worked, I won't miss it, and I guess its another weight saving!

When I get a chance, I'll give it a bit more investigation. The MoT failed on a couple of points, and I had to argue about my exhaust, as they say it failed due to being de-cat'd yet they have passed the car with that exhaust before. But that is a side issue. I'll have to see what the other points are, I think one was a rear brake pipe too.

The dealership were less than helpful, even after the exhaust conversation, I asked for a quote for the other rectifications required, and the service department just couldn''t be bothered, really terrible attitude and customer service (yet the previous year when I spent a fortune doing the cam belt/ water pump, the car flew through MoT - with that exhaust)

Anyway rant over, I won't be going back to Honda with my car, I'll be using independent garages from now on.

I'll report back once I get the dash out again and see what can be done.

Also I think I have a wiring issue with the headlight retractor switch, the connection is a bit loose, and the switch can make the lights go up, but won't retract them! ARGH!

Jim

[Kaz-kzukNA1]

Hi, Jim.

I'm quite sure the S2K dash conversion kit has some sort of instruction to cope with the different ABS warning circuit used based on NSX year models.
There are at least 3 different circuits.

Following info may help you.

S2K ABS dash warning light circuit is nothing special.
It uses IG1 for the power and uses RC circuit with about 2sec time constant for light bulb check mode.

If the capacitor is charged, it will switch On the Zennor diode connected to the Tr base and this will enable the collector current resulting in ABS warning light.
So, if you want to keep the ABS light On, you just need to create open circuit at the WALP line of the S2K dash so that the capacitor is always charged.

If you want to switch it Off, you need to keep the capacitor discharged.
Just drop the WALP line to GND using the WARN circuit on the classic ABS controller.
It will take about 2sec to switch it off and hence, used for the light bulb check mode.

With classic ABS controller and the ABS warning light circuit configuration on 91 – 94 NSX,
the logic is reversed so if you just connect the WALP line of the S2K dash to the WARN terminal of the classic ABS controller,
it will continuously switch On the ABS light in about 1sec after turning the IG key into P2 or after starting the engine even if no ABS issue is detected.

You just need to reverse the logic and use NC (Normally Closed) type relay.
91 – 94, 95 - 96 and 97+ models use different ABS warning light circuit and above method is only for the 91 -94 one.


For your headlight issue, if both headlights don’t retract themselves,
then please first check the state of your retractor switch located at the right side below the gauge assy.




https://lh3.googleusercontent.com/mRNpCQ4ntxXtqyBerV3iykAQ1I4V14x7d-GGV5aFUgdj1zsQwhcj3fGpO3JqcakwIgcYCWjjYa61d6xJZllL zmYqSujfNLWMq4vP5k_65OxQVVbD1FHRNiljI-n7UNNycdPmBe-JT1iVEkCJjIS1p6cBa2NobIB4Vr4ottXkMTquDbhVSBTirVhP2 FtYVyCOITw6KqNKvErbhiI6tN5qUGeoqyZrGfNRuMGtQqYBHg5 nzJWJqeHV9BvDW5O4xtgRPKpulhLrhBMBq1E06rgM-4rLYzufFU5yhTB5YiaKWgRCTJ0RkV388OHWD3CQcnCcV0oFx7t BRWCZ3svmJoA8H73M_JRPwpbuJSPB9fhLeUhvV0xmbyTkeVHUW ZcnJzsD8ci6akQiTq55aRgqub15iY_pfq1ZfGWRWhqXMHuakpC iPfSAdSWdoXRODiHKZz3UqIO49SifTtba_PYycAUGff_uY2Abw i8HUKBWJJtVaTooLtoXcx2U4gyUJfXOq4B3v_9FQ18R9LQGPBr 17BlTlQS5L5lPUdH4yO4XQ_ZvePjH0zogkyvIBofEmw7Zr5ZWd vQEg3vghKmE_Ya8M5B5wFveFTQpXtUTneh2KbHXMcjrIczBxhO q=w800-h600-no
This photo is not the retractor switch but it showed another issue for the same reason.

Please make sure that there is no gap between the connector housing and the circuit board indicated by the green arrows.
If there is even a tiny gap there, it will cause open circuit that you can pop up the headlight but it won’t retract.

If the diode inside the retractor motor is dead, it will cause the same issue but when this happens, it’s very likely to be at just one side and not at both sides.


Kaz

[hkz286]

just to answer your question about MOT and ABS removal

"If an ABS or ESC system has been intentionally rendered inoperative, the whole system must be removed. However, this does not apply to sensor rings or other ABS components which are an integral part of another component e.g. brake disc or drive shaft."

thats from the MOT manual, presumably to stop people just taking out the ABS fuse and putting it back in, just to get through an MOT.

[paulc]

Is the removal easy? Think mine is giving up the ghost, lots of air forcing the brake fuild to be pushed out of the cap!

[Pride]

Is the removal easy? Think mine is giving up the ghost, lots of air forcing the brake fuild to be pushed out of the cap!

I went through that problem about 10 years ago, I pressure bled the system and it cured the problem with no problems since.

[paulc]

I went through that problem about 10 years ago, I pressure bled the system and it cured the problem with no problems since.

Many thanks,did you pressure bleed the system yourself or get the garage to do it for you?

[Pride]

Honda Chiswick did it for me while I waited for a couple of hours from memory.

[paulc]

Honda Chiswick did it for me while I waited for a couple of hours from memory.

Many thanks might give the local garage a shout and see what they can do.

Regards

Paul

[Pride]

Many thanks might give the local garage a shout and see what they can do.

Regards

Paul

Just make sure they can pressure bleed them:

http://www.nsxcb.co.uk/entry.php?1897-Brake-OH-Cooling-Sys-etc-28

[britlude]

Is the removal easy? Think mine is giving up the ghost, lots of air forcing the brake fuild to be pushed out of the cap!

I take it the fluid is coming out of the ABS reservoir cap, in which case pressure bleeding the system won't help, they are separate systems

if the solnoids/ABS hasn't been exercised for some time, they might be stuck, and will need energising a few times to see if they can free themselves....

try this... http://danoland.com/nsxgarage/brakes/abs/abs.htm

you don't necessarily need the maintenance bleeder to do it, but measuring the volume of fluid that is released will give an indication of the accumulators condition. if you are a competent mechanic, it can be done with a 9mm cranked 12 point spanner and a tube to a container on the bleed nipple 'maintenance bleeder' but BE VERY CAREFUL as it's under high pressure. if in doubt energising the solenoids releases the pressure anyway....

[Pride]

In that case I stand corrected but it's strange I had no more similar problems after it was bled though.

[mutley]

Hi, Jim.

I'm quite sure the S2K dash conversion kit has some sort of instruction to cope with the different ABS warning circuit used based on NSX year models.
There are at least 3 different circuits.

Following info may help you.

S2K ABS dash warning light circuit is nothing special.
It uses IG1 for the power and uses RC circuit with about 2sec time constant for light bulb check mode.

If the capacitor is charged, it will switch On the Zennor diode connected to the Tr base and this will enable the collector current resulting in ABS warning light.
So, if you want to keep the ABS light On, you just need to create open circuit at the WALP line of the S2K dash so that the capacitor is always charged.

If you want to switch it Off, you need to keep the capacitor discharged.
Just drop the WALP line to GND using the WARN circuit on the classic ABS controller.
It will take about 2sec to switch it off and hence, used for the light bulb check mode.

With classic ABS controller and the ABS warning light circuit configuration on 91 – 94 NSX,
the logic is reversed so if you just connect the WALP line of the S2K dash to the WARN terminal of the classic ABS controller,
it will continuously switch On the ABS light in about 1sec after turning the IG key into P2 or after starting the engine even if no ABS issue is detected.

You just need to reverse the logic and use NC (Normally Closed) type relay.
91 – 94, 95 - 96 and 97+ models use different ABS warning light circuit and above method is only for the 91 -94 one.


For your headlight issue, if both headlights don’t retract themselves,
then please first check the state of your retractor switch located at the right side below the gauge assy.




https://lh3.googleusercontent.com/mRNpCQ4ntxXtqyBerV3iykAQ1I4V14x7d-GGV5aFUgdj1zsQwhcj3fGpO3JqcakwIgcYCWjjYa61d6xJZllL zmYqSujfNLWMq4vP5k_65OxQVVbD1FHRNiljI-n7UNNycdPmBe-JT1iVEkCJjIS1p6cBa2NobIB4Vr4ottXkMTquDbhVSBTirVhP2 FtYVyCOITw6KqNKvErbhiI6tN5qUGeoqyZrGfNRuMGtQqYBHg5 nzJWJqeHV9BvDW5O4xtgRPKpulhLrhBMBq1E06rgM-4rLYzufFU5yhTB5YiaKWgRCTJ0RkV388OHWD3CQcnCcV0oFx7t BRWCZ3svmJoA8H73M_JRPwpbuJSPB9fhLeUhvV0xmbyTkeVHUW ZcnJzsD8ci6akQiTq55aRgqub15iY_pfq1ZfGWRWhqXMHuakpC iPfSAdSWdoXRODiHKZz3UqIO49SifTtba_PYycAUGff_uY2Abw i8HUKBWJJtVaTooLtoXcx2U4gyUJfXOq4B3v_9FQ18R9LQGPBr 17BlTlQS5L5lPUdH4yO4XQ_ZvePjH0zogkyvIBofEmw7Zr5ZWd vQEg3vghKmE_Ya8M5B5wFveFTQpXtUTneh2KbHXMcjrIczBxhO q=w800-h600-no
This photo is not the retractor switch but it showed another issue for the same reason.

Please make sure that there is no gap between the connector housing and the circuit board indicated by the green arrows.
If there is even a tiny gap there, it will cause open circuit that you can pop up the headlight but it won’t retract.

If the diode inside the retractor motor is dead, it will cause the same issue but when this happens, it’s very likely to be at just one side and not at both sides.


Kaz

Thanks Kaz, I'll try and have a proper look at it when I get time. IS there a way to short the connector before the switch to miss out the switch altogether? I don't really need the switch to work if by bypassing the switch would make them operate normally with the headlight switch.

Cheers
Jim

[paulc]

I take it the fluid is coming out of the ABS reservoir cap, in which case pressure bleeding the system won't help, they are separate systems

if the solnoids/ABS hasn't been exercised for some time, they might be stuck, and will need energising a few times to see if they can free themselves....

try this... http://danoland.com/nsxgarage/brakes/abs/abs.htm

you don't necessarily need the maintenance bleeder to do it, but measuring the volume of fluid that is released will give an indication of the accumulators condition. if you are a competent mechanic, it can be done with a 9mm cranked 12 point spanner and a tube to a container on the bleed nipple 'maintenance bleeder' but BE VERY CAREFUL as it's under high pressure. if in doubt energising the solenoids releases the pressure anyway....

Many thanks, yes the fuild is coming out of the reservoir cap. I suspect/know that the solnoids/ABS have not been exercised for a long time, so will have a go at energising them.