Jaguar XK8 Brake Switch Replacement

I recently experienced a FailSafe, Transmission Fault & ABS failure as I was going down the road about 55mph.  Pulled off to the side of the road turned the key off and restarted the car and all was good.  Conditions were no OBDII or check engine light and the cruise control was on and active at the time of the problem also this car has 122,000mi on it.

I had heard several say the brake switch is a common cause and that it was difficult to replace the brake switch and for that reason I elected to look over this job and attempt to take the right approach.  I replaced the switch but it took two of us to do it.  One person on the top to guide the person installing the switch on the bottom, this procedure took about 30min.  I would recommend that the smaller person be the one installing.  You will see the stick that helped to maneuver the switch around that made it a little easier but the key to the install is the proper aligning with the bolt holes that you are unable to see.  We paused for a moment to look the situation over for an easier approach and what we came up with was to align the switch with the switch striker from the brake pedal and it worked.

After looking at the switch much after the replacement I noticed 2 bolts that would enable you to remove and reinstall the switch assembly from the mounting bracket.  I did not do this myself but I feel it was a possibility.

I asked myself why this switch was such a problem.  After looking at it and evaluate the process I come to the conclusion that the switches were out of sequence because both switches worked in unison every time I tested it.  As they work in unison one switch is open (NO) for the brake and the other is closed (NC) for the cruise control and both report directly to the engine control module.  If Either one of the switches had an intermittent problem or they were out of sequence and the computer saw this it would have identified this as a problem causing it to go into a FailSafe mode.  I will continue to monitor to be sure it took care of my problem.