ABS light

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Chongo

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When replacing the front brakes, if your ABS light comes on it probably means you disturbed the sensor. If you remove them and then reseat them, the problem most likely will go away. They are not positively retained like on most cars. Another common cause of ABS lights coming on is loose wheel bearings.
 

ravensfan1996

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My ABS, TC and downhill lights all came on yesterday. The car seems fine and brakes. Is this one for those quirky things that happens to land rovers that can be fixed? or does it indicate a problem?

I havent had any "recent" brake work done. I did have the rear brakes and brake line redone about 3 or 4 months ago.
 

Chongo

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We need the codes.

If the lights on the dash came on You need to go to someone who can read these codes and post your results. Without knowing the trouble codes it’s anyone’s guess.
 

Redrocker

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Could be several things, but this did happen to me under warranty and I had a bad wheel hub sensor. Could be worth checking into.

Chad
 

Chongo

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Warranty

I sure hope it is still under warranty, it's more money in your pocket. If you have an air compressor try blowing the dirt off of it and re-seating it first. In my findings I'm finding alot of small magnetic mateial from the road clung to the sensor, making it misread as a faulty sensor. i've been removing it by forced air from an aircompressor. And it has worked so far every time. Sometimes it takes a little re-seating too.

Have a good one.............
 

ravensfan1996

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Nope no warranty, its a 2000 i bought used. Ive heard others state try power washer or air compresser to get out the dirt. So ill try that first. Its been very dry here in the md/pa area so might be very dusty/dirty. Im no gearhead but is it "easy" to rseat?

and where are the ABS sensors located? is every wheel? or only front wheels?
 

Chongo

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ABS systems

ABS Systems
The Discovery II electronic braking system, called SLABS (self leveling antilock braking), is made by Wabco of Germany. Wabco is a subsidiary of American Standard, a company better known to the public for toilets than brakes. In the automotive field, Wabco specializes in braking and suspension systems for trucks. According to the Wabco, two out of three commercial vehicles with advanced braking systems are equipped with Wabco products. The Land Rover system includes four-wheel antilock braking, hill descent control, and four-wheel traction control. The SLABS control unit also controls the self-leveling suspension, if the vehicle has that feature. The Discovery air suspension is also a Wabco product. As an aside, Wabco air suspension is also found in the new Audi A6 and the Mercedes CLS.
One of the most common ABS questions is, Why do I see the ABS, Traction Control, and Hill Descent lights coming on? All three of those systems share a common set of
core components. The wheel speed sensors, the hubs, the modulator, the controller, and other parts serve all three systems. So a fault in any one of them will cause a problem in the other two. It is actually rare to have a fault that would only disable one of the three systems. 99% of the time, if one is affected, they all are. To see what’s wrong, you will need to connect a Land Rover test system and read the faults. These systems are not OBD II compatible, so a generic scanner won’t talk to them. You can use the T4
or Autologic tools for this work.
The most common faults are wheel speedsensor faults.
The wheel speed sensors in a Land Rover are coils that sense the motion of a toothed wheel that’s a part of the wheel hub. The rotation of the wheel induces a sine wave signal in the sensor whose frequency is proportional to the speed, and whose amplitude increases with speed from 0.5 volts to more than 5 volts. If your Rover has a speed sensor fault, there are two paths to repair. The first is to replace the entire hub on the affected corner. This is the approach favored by dealers because the toothed wheel – called a reluctor ring – and the actual sensor are both part of the hub. The reluctor can get damaged by rust or corrosion, and it can also get damaged by a bad wheel bearing. The only way to service it is to change the hub, or you can try and have it sand blasted. As of this writing, hubs (front-RND646 / rear-RND694) cost around $400 and take about three hours to change. The sensor can be removed from the hub fairly easily. If you remove your sensor and look inside you should be able to see if the reluctor ring is damaged. The reluctor ring can get damaged if the wheel bearing gets loose. It can also get damaged by corrosion. That’s especially true for Rovers that run on beaches. If you see reluctor ring damage, or corrosion, or if the hub has any free play at all – you need a complete assembly. If there is no damage, you may be able to fix the vehicle by changing the sensor (front-RN292 / rear-RNH293) alone, a $100 part that’s less than an hour to swap. The path you choose should be determined by examination of the reluctor via the sensor hole. If the hub looks good, there’s an “8 or 10” odds that a sensor alone will fix your problem. Every now and then you will see a Rover that has wiring problems, usually at the connector between ABS sensor and body. Always pull it apart and look for corrosion.
The next common fault in these systems is called shuttle valve failure. The shuttle valve is a part of the brake modulator – that big thing in the location where a master cylinder would be. The modulator incorporates the functions of an ABS servo and a brake master cylinder into one unit. If you have shuttle valve problems, you will see the three warning lights on the dash and there will be one or more stored faults for shuttle valve failure. Land Rover has a test procedure to determine if these
faults result from a failure in the modulator or if they are caused by wiring troubles in the ABS harness or grounds. Unless you have corroded grounds and cables, your trouble is probably in the modulator. Until now, this problem was addressed by replacement of the brake modulator (RNH082). That’s a $1,500 part. As you can imagine, shuttle valve failure produced a lot of unhappy owners and Land Rover
finally listened up and developed a fix. As of March 2006, Land Rover sells a shuttle valve repair kit for under $100. You will have to remove the modulator and flip it over to install the valves on a workbench. Removal of the modulator, replacement of the valve, and refit to the vehicle takes three hours or so. This shuttle valve repair is a huge improvement over the former method of addressing this problem.
The part number for the repair kit is (SW0500030). If you buy it from a dealer you may also want to ask for the March 2006 bulletin that gives test and installation instructions.

Another common problem is a mushybrake pedal. In my experience, the only explanation for a mushy pedal is improper bleeding procedure. Bleeding a Discovery II takes two people and the Land Rover test system, and it takes the two of them a bit over half an hour. You need the tester to operate the pump and valves to make sure all the air is purged from the modulator. If you are paying for this service, expect a labor bill in the range of one and a half hours and $20-30 of brake fluid. If you are not at a dealer, make sure they use the correct Castrol LMA fluid. Don’t even start this process unless the shop has a tester to run the pump and valves. You could bleed brakes in the field without one in an emergency, but there is no way to get a really good pedal without cycling pump and valves, and there is a way to do it yourself without an expensive machine.

Stop lamp circuitproblems. The usual way this problem manifestsitself is a truck that won’t shift out of park. Discovery II models have an interlock that prevents shifting out of park unless the brake is pressed. So, if the brakelight circuit fails, the car won’t go into gear. If that happens to you, the first step is to check the stop lamp fuse. I’ve seen several trucks where the stop lamps were fitted wrong, or the contacts corroded, and the fuse blew. Also check the trailer connector, if your Rover has one. A short there can pop fuses. If the fuses are good, you should check the stop lamp switch. It’s located above the brake pedal. If you are stuck somewhere, it is possible to get out of park by jumping the switch temporarily with a paper clip.

Finally, you should check your Rover to see if the brake modulator recall was done. If it was, you should have a B148 sticker on the radiator support. All Discovery II models built before spring of 2003 are subject to the recall. Land Rover found the caps on the ABS modulator were cracking under heavy off-road use. Therefore, they came up with heavier replacements. The caps are a quick bolt on installation. If you are near a dealer they will do this for you at no charge. If you can’t get to a dealer, or you’re
outside the USA, the part number for the kit is SWO500010K. Complete illustrated instructions can be found in the B148 recall bulletin, available from your dealer with the kit. This recall does not involve any hydraulic system disassembly, so the brakes won’t feel or act any differently. The heavier caps are plainly visible on top of the modulator. Once you see them, you’ll be able to tell it was done. Note: Recalls should always be done at your dealer so they can be properly recorded. Only do this yourself if you absolutely can’t get to a dealer, or if your Rover is not eligible because it’s a rebuilt salvage vehicle. Remember that you can access all of the most current service information, including workshop manuals, electrical manuals, recall notices, and service bulletinson Land Rover’swebsite,

http://www.landrovertechinfo.com

If you look on the Land Rover site under “training”you will find the introduction to the 1999 Discovery II. That training book has a 23-pagedescription of the Wabco electronic system.

I hope this helps………. Chongo :bandit:
 

FFNPMcD

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Does this same information apply to the 96 Disco?

Will the ABS light reset itself after the problem has been corrected or does the dealer need to clear the code and reset the light..

If you can save me a trip to the dealer give me some common reasons the ABS light will come on .. and fixes (as detailed as possiable ...I'm not entirely sure what the sensor looks like ... so if one potential solution is to apply soap and water let me know where)

thanks,

Neill 96 Disco SE7
 

Chongo

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Abs

Neill: I will always recommend taking the vehicle to have it hooked up, to the proper diagnostic tools when finishing a repair. To answer the question, “will the light go out if it is fixed? “ The answer is maybe, granted the system is satisfied, but the trouble code will remain in the processor even though the light is off. I don’t remember how many trouble codes the LR - ABS processor retains at one time, I believe it was 4 at one time, I don’t know about a 1996 model. Clearing all the codes is a professional way to do it. This way if a new code is present it won’t send you in the wrong direction, chasing old issues.
Diagnostic tools:

Faultmate sv - will work on only one vin number around $1200.00
Sv = single vehicle

Faultmate mv - will work on more than one vin number around $10,500.00
Mv = multiple vehicle

T-4 - works on all and starts around $5,000.00 I use this one, it’s a little
Clumsy, but I love it, and it's totally upgradeable.

Autologic - works well, smart looking, handy and around $10,500.00 plus accessories.

I hope this helps……………………….. Chongo :bandit:
 

DZACKERY

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If The Ecu Is Bad And U Change, Will It Reset The Lights? I Dont Wanna Pay Another 100 Dollars Just For That. I Know This Sounds Redundant But Im Happy To See That U Guys Are Knowledgable About This Subject.
 

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