Hi I have an 89 xjs, and recently the abs and brake light come on when you hold the pedal roughly 5 seconds go by with your foot on the pedal and then the abs pump starts running and you can feal the pedal pulsing. checked fluid, checked codes, no codes, bled brake system. checked and adjusted brake switch, and swapped out the accumulator and pressure switch. still have the same problem. any suggestions?

 

Most likely your accumulator is on the way out. Put in park, wait till ABS light is out. Switch off. Press brale pedal repeatedly. Pedla should go hard after +/- 15 times. If significantly less replace accu.

 

Ya I put a new acummulator in it allready as per my first post.

 

Do you know what pressure the system is sitting at? The pump operates when pressure drops to 140bar and switches off at 180bar. Have you checked for fluid leaks?

Both ABS and Brake warning lights on indicate system pressure has dropped below 105bar and ABS has been switched off to the front wheels. If this is actually the case there should be no continuity between pins 9 and 10 of the ABS ECM. This is controlled by the pressure switch which I see you have replaced.

 

Anyone have the connector view for the pressure switch on the abs pump?

 

Or if anyone has one of these cars and is willing to take a pic with the wires exposed so I can make sure I have the right wires going into the right spot I would appreciate it.

 

New, or new remanufactured? It is rather too well known that the remanufactured ones are dud or fails in a few days.

 

I could not get a good enough pic to show the wiring colour code so here is the pin out from the book

Connector wiring for switch
Pin Number Colour
1 B
2 BY
3 PG
4 WP
5 WU

 

Thanks, I think that I need a pump. Checked the wiring, and yes the accumulator is new from jag, tried another pressure switch too that didn't work either.

 

I had a similar problem with the pump running for no apparent reason, even coming on while driving on the highway. This usually happened if it was hot out. Solved the problem by using contact cleaner on all connections at the pump AND at the resevoir. Hope this helps

 

Of course great advice and most certainly to do before you buy anything else