Car: Jaguar XJ6 X300 Sovereign, 1997, European model 3.2

Symptoms:

1. Central locking:
   • Keyfob blinks but does nothing.
     
   • Dash/console lock/unlock button does not work.
     
   • Trunk release button (interior) does not work.
     
2. Lights:
   • Interior and exterior lights work normally.
     
   • Side indicators do not flash when pressing keyfob. No sound, nothing.
     

Observations:

• Checked visually all relevant fuses in LH/RH heel boards and trunk; all appear intact also checked visually and reconnected BCM behind glove box and Security module in the trunk. Nothing
  
• Car was parked next to several other vehicles overnight and locked successfully; in the morning (-3 Celsius), it wouldn’t unlock with the keyfob. Replaced Keyfob battery. Unable to dot he keyfob reset connection procedure cause valet button seems to not work.
  

Any ideas?

 

Main car battery charged as may have drained , this would be a resolvable parasitic battery drain you can resolve yourself

Trunk fuse 3 or 4 as the SLCM fuse

Large connector above the fuel tank ( have to remove fwd trunk panel ) has a tie wrap on it clamping connector tight < do not remove connector yet

The batteries in the Fob can be easily installed wrong polarity

Do not install main car battery in backwards , positive post car fwd

Do not over tighten the positive battery post bolt , breaks special nut underneith

There is a SLCM " Hard Reset " but yours is European so a precaution if you have the original Jaguar / Alpine stereo head

Check to see which frequency version of antenna you have on rear glass

 

Car sitting in rain overnight ?

This allows water to pool in the fuel cap well and if the drain line is clogged water will spill over the well on the SLCM 4 connectors driving it nuts or hung up in a logic step not zero state

To clean connectors the battery positive terminal must be removed for SLCM connectors removal and install , keep track of which connector goes were or one at a time still battery cable removed

 

greetings, we have the same issue with out Jaguar x300 4.0L 1996.

the vehicle battery is brand new (very high quality AGM and professionally installed)
battery drained while we were away.
recharged the new batter and it has been tested and is fully charged.
card will not start: turn key, dash lights come on, lock unlock (dash) button is RED. car will not start. no sound when we turn the key.
key fob does not lock or unlock the vehicle anymore (new batteries installed and the batteries were also new before).
dash lights come on.
interior lights do not come on.
trunk light does not come on.
fuel cap will not open.
trunk open switch does not work (can open the trunk with the key only).

if you do fix your issue please let us know.
all fuses were checked twice.

thanks!

 

The starter circuit needs a starter enable from the SLCM , The SLCM can be " Hard Reset " to zero state as yours is a US model without the stereo locking out

Remove both battery cables from batt and join cables together in the air with maybe a heavy battery jumper cable , this is a very low current situation so no fear , place a towel or the neighbors dead cat on exposed battery terminals , the longer the cables together the better like overnight

You can try a short 10 minute cables together then if no joy overnight

This will not effect the engine ECU as in other cars

Never install battery in backwards , positive post fwd and mark with white tape

Never over tighten the positive post battery bolt , splits special nut underneath

This process also resets the BPM which gathers the starter enables like trans position

 

A professional can still install battery backwards , ask me how I know

 

thank you so much! great, i will try this tomorrow morning and let you guys know what happens.

 

ahoy, we tried this (see diagram in case we made an error). no change so far. thanks.

 

Correct on hard reset pic

The fuse for both BPM and SLCM is in the trunk

To get power to the BPM ( starter enables gather )( behind glove box ) it goes through the BT - 4 large connector above the fuel tank which needs a tie wrap on it to clamp tight

Do not remove connector yet , just remove trunk fwd panel and see

There are some terminal nuts to check and the first is the Mega Fuse box just fwd of the batt positive post and then some task on the engine rear firewall battery terminal posts , remove the engine side cars left and right cable ( to the left and right engine bay fuse box ) with the cable removed wiggle the terminal stud , this is power to the starter solenoid

relays in the corner of each fuse box 5 - 1 ? the left engine bay fuse box relay only controls the horn so swapping option

 

thank you, again! we will look at these components over the weekend and post updates here. cheers!

 

the 2 terminals to wiggle are on the engine rear firewall

one other is inside the engine bay on the right wheel well very near the rear firewall , this is the starter cable / alternator feed back direction to the battery and such

and if you look through the intake pipes you will see a junction terminal of the battery cables on the starter solenoid top post that someone made a great pic of . this is a tie point where the right wheel well cable ties to go up to alternator B +

pics coming

 

great pictures! thank you.

 

UPDATE: FYI this Jag is a 1995 not 1996 (just checked the title).

 

Jag x300 4.0L 1995:

Greetings, [see image]

Does anyone know what the Black Relay in the Boot is for? I am hoping that no one stole it -- thus causing my no-start issue. The relay diagram I found online does not have the same configuration as this. Not sure where to buy one, or what the specs are. Thanks.

 

See page 19 , trailer

jagrepair.com/images/AutoRepairPhotos/X300 1996 LWB.pdf

 

thank you so much! i made a blunder with the year--my jag is 1995.

i have been checking the components you mentioned and they all look brand new, clean, and dry. no corrosion at all. need to get someone to help me test the connections as well. and today i located the SLCM and unplugged it, tried to start the jag, no luck. and no change after reconnecting it.

did not break anything. that is a big plus for me. thanks for all of your support.

 

The SLCM has to be plugged in and powered to be able to provide an enable ( digital ) to starter rotation

To plug SLCM back in positive battery post must be removed or the sequence of the many wire pins making will make the SLCM nuts

 

great. thank you. maybe it was already nuts? there were no visible changes after it was plugged in again. still the same dash lights, still the same "no start". the suggestion to unplug it and plug it back in came from a vintage auto restorer here in our area (vintage tech expert). but he is not a jaguar mechanic, he does get all his vintage car electronics working perfectly though--very complex systems. he had done some research and gave me a list of things to try. anyway, if the car is crazier now than before--i have not (yet) noticed. time will tell. heh.

 

The SLCM comes in many part #s based on year ( different freqs 315 or 433 ) and depending on region of world

This is probably the best part # source

Do you have 1 front door lock barrel or 2 left and right ( the SLCM is different and connector wires different pins )

If the SLCM is nuts a hard reset to bring back to zero state

Xj 1995 - 1997 (from 720125 To 812255) (x300) Classic / Security/locking Module | Jaguar Land Rover Classic Parts

 

the SLCM seems okay to me *blink blink*. however, the valet switch appears to be disconnected and i cannot figure out where to connect it as there are two matching female connectors. hopefully i can find an image of someone who has theirs properly installed. if i can resolve that then perhaps i can reprogram the key fob and disarm the system.

yes, i have two locking barrels on the left (driver) and right (passenger) front doors.

the mystery continues. cheers!