ABS relay location on an 89?
 

I've been reading the ABS relay's internal fuse can go on the early XJ6's ... Where is this located on an early car? (89) Is it under the drivers side jag someplace? I see a lot of posts mentioning the boot/trunk but that was on the later cars...

Thanks!
Pete

Hi Pete,

See page 165 of the Haynes manual pdf, which you can download at the link below (and which no XJ40 owner should be without!):

http://www.mediafire.com/?hx8bttsy4kxxr#3267xri9vx4v6

It looks as though on the LHD '88-'89 XJ40s the ABS relays are behind the driver's side knee bolster, probably clipped to the front of the AC blower fan housing. Removing the knee bolster is simple. The photos at the link below show the process on our '93:

Welcome to Jag-lovers - Members Photo Viewing Page

Cheers,

Don

Hmm...I saw that in my book too...but I'm not seeing anything up there... I've removed the drivers side bolster, the driver side fuse box cover, and the instrument cluster, and all I see is a single green relay that's related to the restraint system. Don't see anything on this left side yet.

Hi Pete,

Any chance yours is a late '89 car and is wired like a '90? I think that would only be possible if your car has a 4.0L engine rather than the 3.6L, but who knows...

It might help the rest of us help you if you shared the actual symptoms that are prompting you to suspect the ABS relay? Is your ABS warning lamp illuminated?

Thanks,

Don

I'm trying to get the anti lock failure message off my dash :) I took some looks around and there was a lot of references to this relay, and it seemed like the less dirty of the inspections to start with as well, so I started there. Guess they didn't say it was the easiest to find! :)


Looking in the back, I do have 3 relays in the back left, but according to Haynes, no models have three relays in the back left...according to the workshop manual from Jaguar, the relays are in the proper spot, and they are:

first relay - empty - frontmost
Brake Light Simulation Relay-LS50 (green)
Overvoltage Relay-LS55 (blue)
Fuel Filler Relay-LS11 (black-rearmost)



So I'm not seeing an ABS relay yet, that has a fuse in it...:)
Pete

Pete,

The Overvoltage Relay is the ABS relay you're looking for. In addition to the information available at this forum, it would be worth searching the archives at the Jag-Lovers forum for mountains of information on that relay and ABS diagnostics. Here's just a representative post:

JagFORUM Logon

You can check the VCM for stored fault codes, but unfortunately if I understand correctly, the OBD I system on the early XJ40s did not have any fault codes for ABS problems.

P.S. Note that problems with wheel speed sensors are common, such as accumulation of brake pad dust and gunk, or damage to a sensor's wiring harness.

Cheers,

Don

I am not sure if this is what you are looking for
but with my 88 XJ40 the overvoltage relay was causing the same problem... ABS failure
it is located in the boot on the left side bank of relays...
right under the fuel filler neck
it should be a taller than usual relay and IIRC grey color.
mine has 4 relays on the left side and 3 on the right side (antenna etc)

if your cover is fitted... it will tell you which one anyway lol

Thanks, yeah - I found that one and found some cracked solder joints, etc... the whole thing looks a little sketchy..but I fixed the solder joints and it seemed to go away briefly, but I don't trust it for long... I'll have to do some more research on what this relay cross references to, etc...


Probably good to get a replacement...


Pete

Soldering the relay circuit board is the fix for the Bosch ABS. The relays are expensive and I don't know if they are still available.

I kept several in my toolbox when customers wanted new ones (20 years ago) and I just repaired the old ones and put them back in a drawer. I still have a few somewhere.

Sometimes the fuse in the 'crowbar circuit' blows but it is more common for the solder joints to crack. The fuse is something like a 1 amp or some low value.

I have been known to use a single fine strand of copper wire across the fuse to duplicate the low amp fuse.

It is just to cut power if the voltage exceeds somewhere around 16V (Zener Diode) to protect the ABS module.

bob gauff

Pete, I am new to Jags but this I know...my overvoltage relay is located beside the fuel filler neck in the trunk on the LH side. This is an 88 XJ6 (40). It has a Sovereign badge but the jury is still out on that. It is a LHD Japan spec car. Yes, it is LHD. Incidentally I just found that the relay fuse (internal) was blown. This is an 8A fuse approx. 3/4" long. The relay circuit is simple. A fuse and a zener diode and a relay. If the voltage is adequate the relay pulls in and makes contact. If the voltage is too high the zener effectively shorts to ground blowing the fuse and shutting the circuit off. It's a one way deal. One overvoltage incident = 1 new fuse. Hope this helps. Ron.