How to use Foxwell NT624 to diagnose 2003 XK8 convertible with 93000km?

Car model and year: 2003 XK8 convertible with 93000km

 

Symptoms:
– Rain detector doesn’t work
Steering column doesn’t retract sometimes
– Day/night auto light doesn’t work
– No MIL lamp or message

Those are not big things, but when I read out the BPM fault codes, there are many and I don’t feel confortable with them.

Body Processor module fault codes from my reading device (Foxwell NT624 – nice tool!)

foxwell-nt624-full-system-scanner-1

U1041 Vehicle speed not obtained
U2012 Communication bus error
B1595 Ignition switch – Illegal input code
B1897 Horn switch – circuit failure
B2368 Column adjust switch – out of range
B2351 Column adjust switch
B2331 Column drive reach out of range low
B2334 Column drive tilt out of range high
B2335 Column drive tilt out of range low
B1446 Wiper park sense – circuit failure
B1875 Turn signal switch left and right switch active
B1450 Wash/wipe switch circuit failure

I would like to narrow down to the root cause of those failures, I am suspecting the following possibilities:

– Bad earth or B+ connection somewhere
– Bad connection in the BPM connector
– Partially faulty BPM module
– Partially faulty ICM module

Where would you begin the troubleshooting?

(The battery looks fine)

 

Analysis and solution:

It would seem that most of your problems are centered around the steering column and the turn signal switch. I can’t speak specifically to Jags but in general a heck of a lot of electrical problems affecting everything from brake lights, turn signals, wipers, and even cruise control on occasion can be traced back to a bad turn signal switch and its mechanism. A hell of a lot of a cars circuits go through that single assembly.

As for the steering column tilt and telescope feature there are several threads dealing with the motor and circuits that handle those chores and often it’s nothing but a matter of getting into the motor and gears and cleaning out the aged lubricant/grease that has stiffened with age and lack of use. Could be more serious of course but you can always hope for the best.

Will the steering column move if you repeatedly hold the switch manually? Does in move in small increments manually until it’s where you want it or is it stone dead?

The rain sensor is a microphone hidden in the rearview mirror’s stalk that is facing the window and is sensitive enough to ‘hear’ the rain hitting the windshield. The mike could be bad but given your other problems coming from the trunk signal area I’d bet the problem is there and not at the mirror.

If it was me I’d start with the suggested pinpoint tests dealing with the communication errors so you can rule out problems with the affected modules even though I’m betting it’s the turn signal switch that’s bad.

One other thought. Have you cleared any codes previously or are these the result of your first attempted scans? If they are your first attempt keep in mind that codes stay resident pretty much until cleared and some of them may no longer even be relevant and may have been essentially transient. You have a record of them now so I might clear them and take it for a several drive cycles like you normally would and do a rescan or three to see which ones return. That way you’re not chasing ghosts of a no longer existing problem.

Just my 2 cents though.