Today, my wife's XKR 2001 went into Engine Fail Safe Mode and No Cruise Control.
I checked first with my Autel code reader and there were no codes stored so I then tried IDS and it found P1696 stored. I checked in the 2001 DTC summary and it lists P1696 as a CAN fault on the Adaptive Cruise Control system. This causes the ECU to inhibit cruise control.

The DTC summary lists the probable cause as a wiring fault between the cruise control module and the cruise control booster module and the ECU, or failure of either of the two control modules.

Does anyone have any experience of this or able to offer any guidance please?

Incidentally, just to confuse matters, the Climate Control has simultaneously decided not to expel any hot air. It works perfectly in every way except no heat and this coincided exactly with the above fault.

I checked the climate system and there are no codes stored and the external temp was pretty much exactly what I expected.

Thanks,
Andy

 

Off the top of my head, I would say check the fuses. I somehow remember that the fuse that handles the heater pump (responsible for pushing hot water into the heater core) is also responsible for other sub systems as well. If you are lucky, the cruise control module is one of them...

Best of luck, keep us posted.

 

That makes a lot of sense. I'm just going through the fuse charts now and I'll see what I can find.
Thanks
Andy

 

Resolved.

It was a fault within the security sounder, blowing fuse No.3 in the engine fuse box. This also knocked out the power supply to the two cruise control modules which created a CAN fault which triggered the engine control module to go into Fail Safe Mode and logging the P1696 code.

This fuse also supplies the power to the heater pump relay, hence no heat............and the front fog lamp relay as well as the centre switch pack, so no seat heaters either.

Disconnected the security sounder and popped a new 5 amp fuse in and hey presto..........

Andy

 

This has been reported before. The UK security sounder modules come with a built-in battery that can leak over time and fail. From memory, they can be restored, or replaced. Glad you were able to find out and isolate the problem.