Abs not working

[papin]

Hi all,

Coul anyone help with an ABS please?

Last Monday went for an MOT, failed.
Need some welding as expected, but they found problem with an abs light on dashboard not showing went ignition on before start.
I went to try it and to my surprise when I hit the brake pedal, front wheels locked without abs working.
Would that be a faulty sensor?

Thanks
Martin

 

[jims-terrano]

When a sensor was faulty on mine the light was on all the time shortly after setting off and would stay on.

Check fuses and then check the bulb in the dashboard hasn't failed.

 

[solarman216]

If the light is not showing then someone has diabled it and the ABS is not working, as for why, yes most likely a front wheel sensor, but could be more a hook up to a compatible diagnostics unit will tell you more and it does not have to be Nissan many garages now have the program, Rick

 

[rustic]

Hi all,

Coul anyone help with an ABS please?

Last Monday went for an MOT, failed.
Need some welding as expected, but they found problem with an abs light on dashboard not showing went ignition on before start.
I went to try it and to my surprise when I hit the brake pedal, front wheels locked without abs working.
Would that be a faulty sensor?

Thanks
Martin

Just a bit of history required.
How long have you had the truck, have you put it through an MOT before?
Did you notice the abs light working in the past?
Have you just noticed the front wheel lock up before?
Just asking, in case it was a bodge to get it through the last MOT.

The cheapest fix is to repair a broken wire on a wheel sensor, a bit of soldering and heat shrink sleeving required, or replace the sensor.

I am just going by what had been said in the past, mine doesn't have abs, too old... lol so never tried the fix.
Hope it helps.
Rustic

 

[macabethiel]

No ABS light showing ?

As has been said by Rustic we need to know some history to guide you as to the cause.
If you have owned the vehicle for a couple of years and the ABS check light has worked previously then start with checking if the bulb in dash has blown.

If you only bought vehicle with it's last MoT then it is quite possible that someone has removed the ABS bulb or even worse put some black silicone in the dash unit to block out the light.

That being the case re-fit the bulb or remove black silicone and start by checking the ABS wires near the wheel sensors.

 

[papin]

I bought it 2 years ago and past 2 mot. Just thinking about it, can't remember the abs light working at all, so when it went through last mot the technician must have overlooked the light.

I have checked and replaced light bulb in dashboard. It is working but stays on while driving. Possibly sensor now.

 

[elty001]

The near side sensor wire is prone to breaking inside the insulation.
I've had to replace it on two of the terrano's I've owned over the years.

 

[Mav96]

I thought it was more common for offside as on mine, but either way just check the codes to see which side if any

 

[elty001]

I thought it was more common for offside as on mine, but either way just check the codes to see which side if any

always been the nearside on mine,i suppose its the weakest link which ever side.

 

[macabethiel]

ABS lights.

On my various vehicles it has usually been the nearside front due to that side getting more water exposure when driving on the left.

It is generally one of the sensors that causes the problems as the ABS pumps are pretty reliable even when brake fluid changes have been less than regular.

Other causes can be reluctor rings of course often due to corrosion but more often than not that can start with intermittent fault / flickering light / coming on above 40 mph.

My vote is its a wheel sensor / and or associated wiring.

 

[rayf3262]

Here's a step by step guide posted by another member a while back...

REPAIRING SENSORS (1.1ohms to 1.3 ohms off the top of my head)
The sensor is a problem on T2 See below

REPAIRING SENSORS

your old sensor can easily be repaired the sensor very rarely goes wrong its the wiring that connects it that breaks down and can be replaced by a competent DIY person or an auto electrician with very little kit needed you need a multi-meter a soldering iron and solder some heat shrink (resin sealing is best) and some cable.

1. Too find the faulty sensor jack up and support the front of the vehicle on axle stands and remove the front wheels.

2. disconnect both front sensors from behind the rubber splash guard (follow the cable to the chassis) and unbolt the brackets that hold it to the suspension (do not remove the sensors from the hub as they will be rusted solid and you will damage them getting them out )

3. switch on your multi meter and set it to ohms connect the two leads to the two connectors inside the plug of the sensor lead (it doesn't mater which way round ) you should get a reading (1.1 ohms ~ 1.3 ohms off the top of my head) get some body to hold the plug and multi-meter leads while you wiggle the cable if the reading on the multi-meter changes that is the faulty sensor you may have to bend the cable quite tight to find the broken wire its usually in the last bit of protective sleeving (rubber hose ) before the sensor.

when you find the faulty one lay it on a piece of cardboard and mark the positions of the sleeving and the brackets as you will need to remove these and put them back on later you can prise the metal brackets off with a screw driver and after cutting the plug off the end of the sensor lead (leave a bit of cable to reconnect it) you can slide the sleeving off with a bit of wd40

cut open the protective casing of the twin core cable and strip it back revealing the two cables work your way to the sensor you will probably see the broken wire just after the break cut the cable and find a length of new cable of the same size (this is important) there are plenty of car electrical shops that will help you solder the new cable onto the sensor and cover the join with heat-shrink i use one that seals its self with a resin when you shrink it to make it water proof then cover both cables in heat-shrink to form another protective layer and replace the rubber sleeving and support brackets and solder the plug back on the end and use heat-shrink to seal it again reattach the support brackets and reconnect the plug replace the wheels and the job should be done make sure you check both sides as they may have both gone.

when you test it switch on the ignition and start the engine the light will come on for a few seconds then go out the pump under the bonnet will hiss once then stop road test the vehicle the light should stay off and the pump should not hiss under the bonnet.

hope this helps if not you will have to search the breakers for a second hand one which may not be in any better condition and they are as rare as rocking horse pooh trust me i have looked for one!

another thing that can effect it is the slotted ring that turns with the front hub the sensor has a magnet inside it and when this slotted ring turns it senses it and tells the abs Ecu the speed at which the wheel is turning the Ecu monitors all the wheel speeds if the abs senses that a wheel is about to skid it turns the brakes off it activates the abs mode on that wheel. The trouble is the slotted ring gets clogged with mud grease and metal fillings from the brakes and the sensor is fooled into thinking the wheel is skidding.

POWER SUPPLY FUSES
Check fuses, 21-10amp, 25-10amp, 28-10amp, 49-20amp and fuse 50-10amp these are power supplies to NATS and the ECM.

Glen

Also worth attention...........

Not sure about Patrol half shaft details, but on the Terrano there is (or should be) a snap ring that fixes the half shaft position to the hub, if not there the shaft can float, possibly allowing the reluctor ring to move out of the range of the sensor.

http://www.nissan4x4ownersclub.com/forum/showthread.php?t=20501&highlight=float

http://www.nissan4x4ownersclub.com/forum/showthread.php?t=24849&highlight=float

 

[papin]

Found the faulty sensor.
I have been trying every wheel individualy by lifting front and rear and it's nearside rear sensor. Just hoping I will find one for decent price.

 

[solarman216]

Found the faulty sensor.
I have been trying every wheel individualy by lifting front and rear and it's nearside rear sensor. Just hoping I will find one for decent price.

At least they come out easy as oily from diff oil, I might have one, but have to get it off and wire runs half way up chassis and this particular motor is on the ground, so not easy to get to, Rick

 

[Banshee]

When it comes to ABS sensors on these trucks ALWAYS go new!!!

They are such a ballache to remove :doh

 

[elty001]

The rears come out easily but will need to replace the o ring if you put in a used one :thumb2

 

[papin]

I am going to do a bit of welding around the seat belts and will have a go on the abs rear sensor.
Is it worth to get new one for £45 or shall I get used one?

 

[solarman216]

If you can get a new one for £45 then get it, Rick

 

[papin]

Hello Rick, how much do you want for a used one?

 

[solarman216]

NSR you say, will have to get it off first and check it's condition, but will not be able to do that till the week end, Rick

 

[papin]

It looks like that my abs sensors are playing about. It might be different one after all. Went to my friends garage plugged in to a computer and couldn't get any reading at all, gave to do it manually with ohmmeter I think.