can someone please enlighten me as to what the ecu? is below the rear window in my x300 3.2 .
thank you

 

I believe the ECU looking item on top of the fuel tank, under the rear window is something to do with the stereo system, as in Premium sound versus Standard.

Mine is the standard system, and has a large multi-pin plug on top of the fuel tank, and no ECU looking device up there.

 

Thank you Grant ,
but now am even more confused , haha ,
i disconnected it just to eliminate all non essential systems from the electrics and the dash failed to power up at all , no warning lights , check lights or anything . it would appear that it does a bit more than just the sound and phone system .

 

I don't have premium sound either, but this is the amplifier: JAGUAR XJ6 X300 HARMON KARDON OE UPGRADE AMPLIFIER | eBay. It appears to have Harmon Kardon written on it and a finned top, so it should be pretty recognisable.

What I do have is a Nokia GSM system, which is connected to an aerial on the rear screen. That's equally identifiable from the labels.

But, neither of which should cause your electrics to fail if unplugged. The battery is in the boot, so if you pull or the carpet out does the wiring give any clues? Are there any labels on this mysterious item? How far through the loom to the voltages get?

 

When you say "under the rear window" do you mean beside the filler neck?
If so this is the Security & Locking Control Module.

 

no, i hav4e had numerous problems with the immobiliser , could find that one with my eyes shut , haha , this one is just off centre , above the fuel tank , and has a multi pin connector that plugs into it , through the metalwork , which is locked in with a lever arm lock type plug . you cannot see the unit , i assume you would have to remove the rear parcel shelf to get to it .

 

I found a diagram, it is 12.5mb, so too big for here.

It shows the CD player as off centre, with the "Premium Sound" amp to the left of it. Both on top of the tank.

Send me a PM if you want it, with your email address.

 

Perhaps it is the old Motorola mobile phone interface? I don't know why unplugging it would cause other malfunctions, but most cars don't have that ecu. Maybe when installed it required a dealer level programming, like PECUS? Bob and the wizards will tell us what they know about it.

 

thank you to everyone trying to help i am going to take a picture to post to make life easier .

i would pm you grant if i could work out how to do it . haha .

 

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