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Old 25th October 2020, 20:07   #1
drjonts
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Default ABS Light on...could this be the reason?

Hi Folks,

Hope everyone is OK during these strange times.

MOT is due on the ZT-T at the end of this month and just as I started to get things together to check it over and put on my set of refurbished hairpins and new rubber the ABS light came on with the handbrake light. Failing the electronic self-check and light on all the time. No speedo and a possessed fuel gauge made me buy a new front sensor as a matter of course from DMGRS. Plugged it in and still failed the self test.

So, bit the bullet and whipped out the battery to access the ABS module connector to check for corrosion. Hey presto, slightly fluffy pins! So small bronze brush and some isopropyl alcohol and started to clean the pins. One bends over and then snaps off when straightened...followed by 3 small pins giving up! So, that's that for the module/solenoid side of the ABS unit.

So I got a s/h unit ordered off ebay and with nothing to lose I started to undo the 6 screws that hold the module and solenoids onto the unit body to have a look at the potential for replacing that rather than breaking into the hydraulic circuit (did this on a Mondeo previously with a good result).

After much awkwardness and using all manner of ways to drive / turn several different Torx T20 bits, all the screws were out and the module front can be simply slid off...or so I thought.

Had to lever it off and in doing so 7 of the 8 solenoid coil units remained on the posts of the main body and look at the state of things (apologies for the large images...now sorted)! Quite surprised to see corrosion like that inside a pump's solenoid unit. Seal appears intact but water or water vapour has been in there doing damage to everything for some time!




So I put some PlusGas on them and left them for a while to soak. I returned with my medium-sized SuperWrench and had to rotate each solenoid back and forth to loosen the corrosion bond and slide them off the posts.

Here's the remains of mine on the left compared with the module box off the replacement.



Hoping that this will solve the problem. Fingers crossed and I'll let you know.

Cheers and stay safe,

Jonty

Last edited by drjonts; 26th October 2020 at 12:24.. Reason: Biiiiiiiiiig pictures!
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Old 26th October 2020, 09:39   #2
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Morning!

Having a 'just-in-case' thought here...if a brand new modulator/pump unit were obtained from Rimmer Bros...what is needed via T4 to get it to work? The listing says that the new ones require a T4 session.

S/H ones seem to work OK as plug and play by all accounts.

Do the brand new ones come without any programming and so needs a session to link to the car?

Any advice gratefully welcomed.

Thanks.

Jonty
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Old 26th October 2020, 11:01   #3
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WOW. Your three foot wide post is very hard to read.------Why so BIG ???
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Old 26th October 2020, 11:51   #4
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Sorry Jon...I think it's the hosting site...left the pictures huuuuuuuuuuuge.

Will try and re-size for everyone...hang on...

...and done!

Last edited by drjonts; 26th October 2020 at 12:06..
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Old 26th October 2020, 17:01   #5
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Update...

Solenoid and connector / electronics block from the S/H module installed on the pump / valve body in the car so no need to break into hydraulic circuits.

ABS light goes out as it should so the system is passing the static test!

Now I'll need to take the car out for a drive and make sure the sensors aren't going to give me a headache, but so far...it's looking good!

Jonty
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Old 26th October 2020, 21:18   #6
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Have you sorted it out . Abs light and fuel gauge issue all usually leads down to o/s/f hub from my experience .
You won't find a fault . Hub . Bearing and abs sensor cured the issue for me and looking at it you could not find a fault the mystery of rusty old metal maybe
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Old 26th October 2020, 21:55   #7
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Quote:
Originally Posted by drjonts View Post
Update...

Solenoid and connector / electronics block from the S/H module installed on the pump / valve body in the car so no need to break into hydraulic circuits.

ABS light goes out as it should so the system is passing the static test!

Now I'll need to take the car out for a drive and make sure the sensors aren't going to give me a headache, but so far...it's looking good!

Jonty
Wow, what a mess. Waiting to hear if it's all worked out. Got the same ABS issue myself but until your post had no idea what to do next - thanks it's likely saved me a T4 session and £50.
By chance I'd obtained a S/H modulator only a couple of days ago (off 2-Diesels on here) so I have (I hope) a doner replacement solenoid unit to try rather than upset the hydraulics.
Initially my light came 'on' but would extinguish with the ignition being switched 'off'. On restart the light would remain off and I could drive for any distance until I used the brakes (which was accompanied by a sort of intermittent light grating/grinding noise) then the light would come on again; now the light is constantly on and the intermittent noise has ceased altogether (in other words the modulator has completely ceased operating).
I also found my cruise control stopped working so can I presume cruise control utilises the wheel speed sensor(s), anyone know if that is because the ABS is showing faulty..?

Last edited by rab60bit; 27th October 2020 at 11:03.. Reason: Spelling....
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Old 26th October 2020, 22:18   #8
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Quote:
Originally Posted by rab60bit View Post
Wow, what a mess. Waiting to hear if it's all worked out. Got the same ABS issue myself but until your post had no idea what to do next - thanks it's likely saved me a T4 session and £50.
By chance I'd obtained a S/H modulator only a couple of days ago (off 2-Diesels on hear) so I have (I hope) a doner replacement solenoid unit to try rather than upset the hydraulics.
Initially my light came 'on' but would extinguish with the ignition being switched 'off'. On restart the light would remain off and I could drive for any distance until I used the brakes (which was accompanied by a sort of intermittent light grating/grinding noise) then the light would come on again; now the light is constantly on and the intermittent noise has ceased altogether (in other words the modulator has completely ceased operating).
I also found my cruise control stopped working so can I presume cruise control utilises the wheel speed sensor(s), anyone know if that is because the ABS is showing faulty..?
Thanks John - will let you know what happens when I go for a spin. I am hopeful that it will be OK.

I think (and someone please chime in) that cruise control uses a signal from the NSF sensor. I would take a guess that if the light extinguishes after the ignition is turned on that the sensors and module are passing their static test. If the problem then manifests on driving / braking then it could be the reluctor ring in the bearing (or maybe dirt etc somewhere) that is causing signal problems when braking and your ABS is then kicking in as it thinks you have a wheel locking.

I am just theorising here and I am sure someone has a more definite answer that might narrow down your problem solving options.

Keep us posted.

By the way...taking the front of the modulator is a bit tricky and I had to unbolt the modulator and brackets as far as I could and then went through many types T20 torx bits, extensions, flexible drives and spanners until I was able to get them all undone. it was a tad awkward and you need to flex the pump position without straining the hard pipes too much to get everything unbolted and free but it is possible.

Jonty

Last edited by drjonts; 28th October 2020 at 07:41..
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Old 26th October 2020, 22:24   #9
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Quote:
Originally Posted by It runs View Post
Have you sorted it out . Abs light and fuel gauge issue all usually leads down to o/s/f hub from my experience .
You won't find a fault . Hub . Bearing and abs sensor cured the issue for me and looking at it you could not find a fault the mystery of rusty old metal maybe
Thanks Peter. With the light on all the time the car wasn't passing the static test so looked like a sensor problem. I took a punt that the OSF sensor was most likely at fault, so I got a new one from DMGRS and just plugged it in to see if that got me through the static test...it didn't.

I looked further upstream in the wiring of the sensor itself and then got back to the main ABS module plug where I found the corrosion on the pins...some of which subsequently snapped off and then the fun began!

The light is now extinguishing with the replacement connector and solenoid block so I am hoping things are looking up. Mind you...yet to go for a drive but I am crossing my fingers.

Will let you know how it goes.

Cheers,

Jonty

Last edited by drjonts; 26th October 2020 at 22:41..
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Old 27th October 2020, 18:04   #10
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Hi folks,

Just to update that the swap of the ABS ECU/solenoid block has in my case solved the ABS light being on, speedo not working and the haunted fuel gauge.

Light now extinguishes after ignition on, speedo fine, fuel gauge steady and ABS working when required. So, it's adjust the handbrake and fit the spare alloys with new boots tomorrow and off for MOT on Thursday.

Cheers all.

Jonty
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