Member
Hello brothers & sisters,
I've recently taken ownership of a beautiful e36 318Ti. It goes like stink and the interior roof fabric is stapled in place, ahh the joys of receiving a free car...
The condition of getting a free car was that I had to MOT it, bugger! Well it failed and I've resolved everything that was wrong with it accept the fact the ABS light does not illuminate.
Firstly, is it possible the car doesn't have ABS? It's a 1998, I know ABS wasn't mandatory until 2004.
I have replaced the bulb in the dash so it's not that. What I have noticed is that the ABS fuse relay is non existent. Am I right in thinking it should be a large red one next to the ASC relay? The car seems to have an ABS pump and it has wheel speed sensors, maybe the ABS was removed? What the fuck can I do?
Member
Is there a problem with abs? Why are you expecting it to illuminate
Verstuurd vanaf mijn LG-D855 met Tapatalk
Member
Don't know, don't care to be honest, I don't think I need it. Problem is when you turn the ignition the ABS light is meant to flash on for a second or two. Mine doesn't come on at all and that's causing it to fail its MOT.
Beautiful car by the way
2nd is the 1st loser
Here is a layout of the fuse box that is under the hood, please make sure you have ABS and ABS pump relays:
Member
Ahh i have neither, I think i need to take it to a different garage...Originally Posted by DJ Genius
Here is a layout of the fuse box that is under the hood, please make sure you have ABS and ABS pump relays:
Member
It may be defective and someone pulled them so you would not notice the light on to say broken when you bought the car
- - - Updated - - -
Check the relay and fuse diagram on your fuse box lid before jumping to conclusions.
Also you may be better on a UK forum. My understanding is in the US as long as it passes emissions no one appears to care if the car is falling to pieces
No warranty of any kind implied or given and no liability for any loss, damage or injury, no matter how incurred accepted.
Member
Just to update I gave bmw the chassis number and they confirmed the car does not have ABS
Member
I'd be very surprised if that's right.
No warranty of any kind implied or given and no liability for any loss, damage or injury, no matter how incurred accepted.
Member
Me too.
If there was a chance it did not have ABS, the MOT inspector should know and not require a light to work on a feature that is not even installed.
My guess is that the ABS does not work and somebody pulled the relays to keep the light off. The ABS valve body thingy, follow the brake pipes from the master cylinder to an aluminum cube-shaped thing with a bunch if pipes going in and coming out. There are solenoids inside that do the ABS stuff, and there is a ribbon cable in there that is known to break. When the ribbon cable breaks, the ABS light remains on continuously.
Member
Having said that, if you do not have the valve body, then you do not have ABS. I'm thinking you should see 5 pipes, two that go in and 3 that go out to the wheels. There could be 4 that go to the wheels, this would give you 6 pipes. There are two pipes going in to operate diagonal corners, and either 3 or 4 going out. If there are 3 going out, then you get one to each front tire and one to the rear axle. If there are 4 going out, then you get one to each tire on the car. You can look to see if you even have ABS, if not then the MOT inspector needs a new job.
Member
An ABS pump and manifold should be easy to spot under the hood.
Attn. NEWBIES: Use the search feature, 98% has already been discussed.
Click the search button, select "search single content type", select the "e36 sub forum" specifically, try the "search titles" then try the "search entire posts".
Member
check out the following
As a MOT requirement, the ABS warning light on the dash should illuminate at power up and extinguish after a few seconds. This means the ABS computer is doing a quick self test on all the sensors. If the ABS light stays on at power up or the ABS waning light comes on during your journey, there is a problem. But where? Fortunately on most ABS systems you can read the fault codes it stores either by a TECH1 reader or by the free DIY method. Most sensors of the ABS system are 'hall effect' sensors. These are little robust sensors that have no moving parts or maintenance required. Hence they are usually very reliable. A hall effect sensor is bolted to every road wheel, to monitor the movement of each wheel. These are commonly know as 'road speed sensors'
What do I need to test these 'road speed sensors' ? To test these sensors, you need a DMM (Digital Multi-Meter) and some metal. A oscilloscope is an advantage as you can 'see' the sensors return signal to the ABS system. How do these 'road speed sensors' work ? A hall effect sensor 'sees' iron. It works on magnetism. When a metal containing iron passes by the sensor, it cuts 'flux' on the coil of the hall effect sensor. In this sensor is a coil of wire, with a current flowing through it. When you 'cut' the flux, it varies the current flow. The ABS computer is monitoring this change and can tell when metal is passing its path. On the wheel hub is a crown wheel, with lots of gaps in a metal ring. The road speed sensor is bolted near to this crown wheel and when one of the teeth comes spinning past, it cuts the flux on the hall effect sensor winding. This is how the ABS computer knows if the wheel is rotating or not. If the wheel stops, the teeth stop passing by and hence stops sending a signal back to the computer. The ABS system now knows that the wheel has stopped rotating.
How do I test these 'road speed sensors'? There are several methods on testing the sensor. Most will tell you straight away if there is a problem with the sensor. But first you must make the basic checks first before pointing blame at a sensor:
Check any fuses for the ABS system. Check that the ABS warning bulb is NOT blown on the dash. If it is, the system is inhibited as a fail safe procedure. Check that the cable form leading to the sensors are in good condition with no cuts, burns or splits. After these simple checks, the following test methods can be applied.
Measure the resistance of the road speed sensor.
Method 1- Check Resistance: Jack up the car and take off the road wheel. The ABS road speed sensor cable should be visible within the wheel arch. Locate the connector (usually 2-pin) and disconnect it. Behind the wheel hub should be the road speed sensor, which is bolted on and near the crown wheel. With your DMM set to ohms, connect the probes to the connector, road speed sensor side (so it measures the sensor and not the ABS system). Take note of the value with the road wheel stationary. Now rotate the wheel hub and you should observe the resistance changing. It may not be a smooth transition, but it should change. If the resistance value does change, then the sensor is OK. If it doesn't, then you may be looking at a new sensor, or there is a broken wire in the small amount of cable form leading to the sensor.
Method 2 - Check Voltage: Jack up the car and take off the road wheel. The ABS road speed sensor cable should be visible within the wheel arch. Locate the connector (usually 2-pin) and disconnect it. Behind the wheel hub should be the road speed sensor, which is bolted on and near the crown wheel. The method here is to monitor the voltage going to the sensor and its return signal. To do this you need to monitor the voltage with the connector connected, flying leads are required. Fit thin flying leads onto the end of the DMM probes. Fit the flying leads onto the connector pins so that when the connector is plugged back together, they still make a connection (but don't short each other out).
With you DMM set to voltage (10v max), turn on the ignition (to supply power to the ABS system and sensors). You should see a voltage reading (you are reading the voltage difference between the two pins). The norm voltage is +5v or +12v (depending on ABS model). Rotate the wheel hub slowly and you should see the voltage difference change. This means the sensor is working and its sending a signal back to the ABS computer.
If the voltage doesn't change, then you may be looking at a new sensor, or there is a broken wire in the small amount of cable form leading to the sensor. If there is no voltage reading to begin with, then the ABS system isn't supplying a voltage source to the sensor. Locate the ABS computer in the car and check the mating connector, ensure it is securely on.
Method 3 - Monitor Voltage Signal: Jack up the car and take off the road wheel. The ABS road speed sensor cable should be visible within the wheel arch. Locate the connector (usually 2-pin) and disconnect it. Behind the wheel hub should be the road speed sensor, which is bolted on and near the crown wheel. The method here is to monitor the return signal supplied by the sensor with a oscilloscope. The scope allows you to 'see' the signal, and it should look like a square wave. To do this you need to monitor the voltage with the connector connected, flying leads are required. Fit thin flying leads onto the end of the scope probe. Fit the flying lead onto the signal connector pin so that when the connector is plugged back together, they still make a connection (but don't short each other out). Connect the ground part of the scope lead to an earth point on the car, anything metal should suffice.
With the scope set up, turn on the ignition (to supply power to the ABS system and sensors). You should see a constant voltage reading (you are reading the voltage coming from the sensor. Rotate the wheel hub quite quickly and you should see the voltage alternating up and down. This means the sensor is working and its sending a signal back to the ABS computer. If the voltage doesn't change, then you may be looking at a new sensor, or there is a broken wire in the small amount of cable form leading to the sensor. If there is no voltage reading to begin with, then the ABS system isn't supplying a voltage source to the sensor. Locate the ABS computer in the car and check the mating connector, ensure it is securely on.
FAQ:
How much does a new ABS road speed sensor cost? Depends on the model of the car, but don't expect much change from £50. Most sensors are only available from a Vauxhall dealer. There aren't many pattern part items available.
How easy is it to change one? According to the Haynes book, the sensor should be bolted to the back of the hub. Simply by removing the bolts, the road speed sensor should come off the hub. Then by unplugging the connector, fitting a new one is the reverse or removal. However, due to personal experiences, the bolts come out easily enough but the road speed sensor appears to be (or rather fells like) its welded to the hub
Can I fit a second hand one from another car? Yes you can so long as its the same type (i.e. for the same model as your car). As previously mentioned, hall effect sensors are very reliable items. If you do get a second hand one, you can follow the simple checks above to see if the sensor is working or not. Just this time wave a metal bolt or screw driver blade past the head of the sensor and see if the sensor detected it or not. They either work, or they don't.
Member
^ Pretty good post but a bit general, for example the E36 ABS prior to the traction control versions only has one brake pipe to the rear and only one speed sensor just on the diff. No point checking anywhere near the rear wheels.
The OPs however, probably does have all those nice things, but if the OP has to ask BMW whether they have ABS as opposed to looking for the ABS unit in the engine bay then they probably won't be able to test it out themselves.
Last edited by E36328Coupe; 08-13-2017 at 07:23 AM.
No warranty of any kind implied or given and no liability for any loss, damage or injury, no matter how incurred accepted.
Member
I'm aware of the ABS pump being on my car which is what has prompted this thread. The BMW rep I spoke to said this is a common problem where some of their older cars are failing due to having some of the ABS parts but the system isn't actually in place.
Member
Your words are confusing. If your car has the ABS pump etc piped in then the ABS is in place, it is just broken / disabled / not working.
If your headlamp bulb was broken you would not say your headlamp system was not in place.
No warranty of any kind implied or given and no liability for any loss, damage or injury, no matter how incurred accepted.
Member
Yes it sounds rather silly, I'm just being told different things from different people. According to this thread some of the E36's didn't come with ABS. I have a list of all optional extras that came with the car. ASC is one of them but no sign of ABS, but if it was as standard it wouldn't be on that list. Maybe I'll take the pump off, it's not like it's doing anything if there's no fuse for it.
Member
The ASC system is an expansion of the ABS
Standard things like ABS are not listed as options
- - - Updated - - -
If it was mine I would replace the missing fuses and relays and then if the light is on read the fault codes.
https://mattersoftesting.blog.gov.uk...y-mot-testers/
No warranty of any kind implied or given and no liability for any loss, damage or injury, no matter how incurred accepted.
Member
I am not aware of any E36 where ABS is an option. It is standard equipment on all E36 cars. ASC (traction control, which has different abbreviations that don't matter here) is an option that some cars will have and others will not have. The main fuse block is located next to the left side hood hinge, between the strut tower and the base of the windshield. Take the cover off of the fuse box, there is a legend and a map inside to show which fuse to look at, and where the relays are located.
It might be possible that the early E36 could have an option for ABS, but surely by the time the end of production rolled around, ABS was standard equipment. I see no evidence that ABS was an option, ever. Your car is EU-spec, so your mileage may vary.
The first thing you have to do is obtain and install the proper relays and get the light to come on. Then you have to figure out why it stays on all of the time, if that is what happens. Just a guess here, but if the light remained on at all times, then someone might remove the relays to make it go out instead of actually fix something to make it go out. If the light goes out on engine start and remains out until some random point after the car is moving, then look to a wheel speed sensor as the cause of the issue. If the light goes off after engine start and then immediately comes on again, then look to the ABS controller/valve body thing as the source of the problems. There are posts on repairing the controller internal wiring -- broken ribbon cable -- on YouTube.
Member
Keep in mind that if you pull the ABS controller, you will be required to fully bleed the brake system before you can drive the car.
I'm not certain, but I believe your car has 4-channel ABS, that means there is ABS control of each of the tires. Any tire that goes into a skid is controlled by the ABS system individually. Two or more tires can be controlled at once, but any tire that comes under control of the ABS is itself skidding.
There is also an ABS that is 3-channel, this gives ABS control of the two front tires individually, and the two rear tires together. If either of the rear tires in the 3-channel system goes into a skid, both tires come under control of the ABS system.
I believe, but am open to correction, that no E36 has 3-channel ABS. It is my position that all have 4-channel ABS.
Last edited by JDStrickland; 08-14-2017 at 12:50 PM.
Member
99% already said
No warranty of any kind implied or given and no liability for any loss, damage or injury, no matter how incurred accepted.
2nd is the 1st loser
Seeing your car is 1998, I believe your ABS is together with ASC, therefore it is called ABS/ASC unit instead of ABS unit. That is where your dealer guy made a mistake, he was probably looking for ABS unit only. Some people call this unit simply ASC or ASC-T.
Member
If you have an ASC on/off switch in front of your shifter, then you have ABS and ASC. If those relays are not in place. The first thing you need to do is buy them and install them in their respective spots. The red relay (ABS relay) goes into the blue colored socket and the grey relay (ABS pump motor relay) goes into the grey socket. Part numbers are as follows. 61-36-1-393-404 Red ABS relay and 61-36-1-393-403 Grey ABS pump motor relay. From there you'd need to get scanned for trouble codes or manually begin with ohming out wheel speed sensors, etc...
Member
Make a big picture of your engine bay and we will tell if you have abs and/or asc
Verstuurd vanaf mijn LG-D855 met Tapatalk
Member
I have two E36s with only one front to rear brake pipe on each and only one rear speed sensor on the diff.
That's how they were until the later years / the ASC TC or whatever stuff came in
- - - Updated - - -
He at least has something
No warranty of any kind implied or given and no liability for any loss, damage or injury, no matter how incurred accepted.
Member
I have a question that I can't find a thread to. I'm just discovering that a previous owner pulled several important bulbs from the instrument cluster. They removed the airbag warning, seat belt warning, system check control, and catalytic converter warning bulbs. I have replaced all the bulbs but when I turn the key on for the self check cycle, only one of those I mentioned lights up. That one is the seat belt warning light and then it goes out after a few seconds.
Can you tell me if all the lights are supposed to light up and then one by one go out as they self check or are there certain ones? If so, which ones are they? If the air bag light is one of the ones that's supposed to light up, why won't it?
I know nothing about this stuff. Thanks in advance for any help and guidance you can give me.
Posting Permissions
Reply With Quote
Bookmarks