Hi all, after slowly working though various codes on the Daimler for all sorts of other things I'm left with just this one:

U1135
SLCM
Security and Locking Control Module
Ignition status (ignition switch position) not obtained

Everything on the car now works, no dash messages or other codes. What is odd is that I can't clear the code even momentarily. Looking through the electrical guides there appears to be just two wires going from the ignition switch to the BPM and then out to the SLCM. Presumably the SLCM can't get the Ignition status from the BPM for some reason. I've looked at loads of threads related to this code but it always seems to be part of a bigger problem with cars not starting or central locking issues.

My thinking is that if there was a problem with the ignition switch circuit it would show in other ways as well. This leaves the SCP network connection between the BPM and the SLCM. The DTC guide gives the following circuits/pins to check:


BT40 -8 -16

Ignition switch to BPM switched ground circuit(s) fault BPM SCP Key Status error

BPM SCP network fault

SCP network fault

Obviously I can check continuity from the BPM to SLCM but as far as a signal that should be getting to the SLCM what would I expect to see if anything when checked with a voltmeter? presumably being a SCP network it's not as simple as 12v when the ignition is on or 0 when it's off?

Battery is good and connectors clean, no obvious water damage to the circuit boards in the SLCM. I've just replaced the Transmission controller with a very similar non visible issue and that fixed a stubborn code so I'm leaning towards it being the SLCM at fault but want to eliminate everything else first before I replace it.

As this code is so isolated and it's not effecting anything else it feels like it must be SLCM specific. Or am I on the wrong track? I could of course ignore it but it's the last one left and it's bugging me!
Thank you in advance.

 

Go and re do slmc solder joints. I bet there is many bad.

 

Do you mean on the module board or the connector?

 

Ok so a bargain replacement part number module has made no difference, reprogrammed the fob to it and again everything works as expected. Same code U1135 sticking still. Pouring down with rain all day so haven't been able to check connections but I read a few threads about the iCarsoft scanner sometimes not be able to clear or reading phantom codes. For a test I used the OBDII function on it instead of diagnostic and that doesn't pick up the code. U1135 isn't listed the DTC lookup part of the scanner either.

Could it be the scanner?

It feels like this is a scp network issue maybe but without a bit more expert info on what I should be checking apart from continuity with the BPM I'm a bit stuck. I can't find a single other occurrence of my particular issue anywhere in any forum. Lots of issues with the SLCM and rear lights, boot locking or non-starting but nothing about just this code with no other issues.

I realise possibly Jag dealers may have better software setup but the car isn't mot'd yet and it's a fun plaything so would rather avoid the potential big bills to track down a code on an old car. My nearest main dealer said they "don't do old cars" which hardly filled me with confidence anyway!

 

I would recheck the network diagnostic description.
The X100 and X308 DTCs are somewhat related and I can't find my X308 listing.

See the XK network .pdf.

 

Ok that maybe points to a problem between the ignition switch and the BPM rather than BPM and SLCM so maybe the fault is further up stream, ok something else to check out first then. Appreciate that thank you.

 

Pcb, but you replaced the module allready.