I suspect other older XK8 owners may eventually need a ECU replacement due to a internal component failure. The symptoms were: rough idle, erratic power, many check engine messages, etc. The smell was a clue and upon investigation the problem was a defective capacitor. I was lucky it didn't start a fire given the severity of the damage to the circuit board. Pictures are attached. My first attempt to repair the damage was to see if anyone would repair a circuit that was badly damaged. No takers.

Decided to purchase a ued ECU from Ebay. The prices ranged from $450 to $750 for a decent unit. Some came with a 30 day warranty and some offered a1year warranty for purchase. I got one for $400 including shipping, installed same and the car is running nicely with no messages.
My question to the very knowledgeable members is this: The Ebay advertisement says the ECU "will need to be flashed." For reference by old p/n is LJA1410AK (079700-6513) and the "new" installed p/n is LJA1410CA (079700-8250). I'm inclined to say "if it ain't broke don't fix it" however, there may be something I'm missing. If indeed the flashing is needed, who does


the flashing?
Thanks for sharing your thoughts.

 

I have a spare put away. I ran it in my 2000 XKR for some weeks without issue before reinstalling my original.
No programming or "flashing" was required.
There may well be instances where plug and play does not work l can only speak of my own experience.

 

all 97s are interchangable. they can be updated with wds/ids but no reason to do so

98 ecms are not because they sync with the ktm

 

+1

LJA1410CA is fine.
There were some changes around the EGR delete in the 97 production run, but your replacement is good regardless. See attached TSB.

I would be inclined not to bin your old ECM just yet: they are becoming scarce and, as you have found, those available are commanding high prices. I'd let an old school TV & radio repair man take a look. The burn looks severe, but there's not a lot happening in that corner of the circuit board and it may well be salvageable.

Dead capacitors are a fairly common problem in the 97MY

 

Thanks for the TSB on the ERG value.
Also appreciate the suggestion on keeping the old ECM as I was about to toss it. Do you know where I could obtain a schematic diagram of the circuit board? It would be very helpful if I found someone to repair the circuit board as you suggested.

 

I don't think there are any circuit diagrams out in the wild. The manufacturer (Denso) is likely the only source of that information and unlikely to make it public.

I'd still give the repair a shot.

 

Michael,
Do you know what the difference is between a LJA1410CA -079700-8250 and a LJA1410CA-079700-8480?

 

Hi,
I don't specifically, but if they're both LJA1410CA then they're interchangeable. The only difference I would expect would be the internal firmware revision. This isn't printed on the ECU itself, but it will show on your VCATS label in the spare wheel well (the /nnn suffix):


from my '98

I would strongly advise opening up any replacement ECM and changing all the caps in there unless that has clearly already been done recently, or the new one comes with a warranty.
I posted a list of the ones required here:
https://www.jaguarforums.com/forum/x...6/#post1806456