Hi Oyster -

Yes, the guy who worked on this car before I got it I call "the Mechanic from Hell". He didn't fix things - he destroyed them.

After thinking about it, in a warm climate like California, I would have put two cooling fans on the ECM.

If you could be kind enough to get me a photo of the foam blocks holding the ECM I would appreciate it. It may be that my ECM is sitting too close to the fan for air to circulate properly. I'm guessing it is an easy fix.

 

Hi Mike -

First, I'm very impressed with your knowledge. God knows where you tracked all this down.

Second, I need a list of things I will need to make the repairs. I am going to order all of the capacitors. Soldering iron and solder I have but those thin wires? Also, looks like some kind of adhesive (silicon?) was used to help hold the wires in place on the previous repairs. Also, some kind of orange paint stuff (I believe that is the scientific description

So, anything I may need, let me know. Also, give me the description exactly as they would be in a parts catalogue. Example: 25 gauge pure copper insulated wire

thanks

 

Hi again.

I remembered wrong about the foam blocks.
It is six all together all on top of the ECM.

Two are glued to the top of the compartement all th way in the back.

The other four are glued to the lid of the compartement.

See attached pictures. (I think some of them are upside down.)

 

Mike -
Here is a picture of the back. I think it cleaned up pretty well.

 

Oyster -

Thanks for the photo. I immediately went out and looked at my car. The cover had only two blocks and the box had none. However, looking around the box I saw three foam blocks lying loose at the bottom. So, I am short one but that is an easy fix.
I didn't think the ECM should be lying loose inside the box like I found it.
Thanks

 

Charlie,

AGREED. LJA1410GA is the P/N my JEPC is showing for your VIN.


(click on the image to enlarge it)

If this had been superseded, there would be a next to the P/N.

Graham

 

posted in error

 

Charlie,
The print in your picture looks fine; however there are some internal tracks that run close to the charred hole.

The adhesive looks like RTV, and the scientific description for the orange paint stuff is probably 'nail varnish'

I spent several years in my early days (when my eyes still worked properly) repairing domestic electronics before the fix/replace cost balance tipped predominantly in favour of the latter and spelt the end of the need for people with the skills for the former.
Most of the information came from the 97 electrical diagrams and poring over the pictures.

I've been meaning to pull the ECM out of mine to do an inspection, and I'll do so in the morning. The unit is made by the same manufacturer, drives mostly the same hardware and is only at most one year newer, yet curiously the 98-on doesn't appear to be plagued by the same failures as the early cars.

 

Graham & Mike -

Graham says LJA1410GA and Mike says LJA1410HB and my VCATS says LJA1410CA (which is what is in the car). So, - perhaps - any of the three will work in the car? What do you think?

 

Mike -

When you pull your ECM out pay close attention to the capacitors. Maybe they upgraded those or something? I would be interested in what differences you note.

 

My bad - Graham is correct & I've edited my post. I was looking in the wrong section of JEPC

For the wire jumpers, see if you can find something similar to what is used for the previous fix. I would suggest using solid conductor as it reduces the risk of 'whiskers' causing a short.
If possible, try to make the solder joint where there's a component attached, a natural pad, or a connector pin. These GRP boards are good quality, but it's easy to lift a track if you get too much heat on it. On your picture, I've circled the points in red where I would attach the jumper (if it had needed one), with the pad in yellow as a second option:


Key is to use a small-tipped soldering iron and make the join quickly to minimise heating of the area.

More laters...

Mike

 

Well, ECM came out - eventually. Jaguar doesn't want you to get inside there. 12 'tamperproof' bolts later and I got the lids off.

I had a feeling that the later module internals would be laid out very similarly in that area, and that proved to be the case. I've taken a few shots, although I'm afraid my phone camera skills leave a lot to be desired:



You should be able to see from the second picture where pin 4 connects to the timy surface-mount component C408. It may be that the track is good on your board and just needs a bit more of a scrub-up.

?721 is C721 which is the burnt cap.

The blue cap upper leg does connect to the copper surrounding it.

I will make some multimeter checks as I need to determine where the logic 12V from pin 3 routes as it's an internal track. Fortunately there won't be many in that area. Again, it may well be good on your board.

I'm the first one in since the car was assembled, and it all looks like new, no sign of leaky caps. They are all Nichicon and look identical to the one remaining original that you have.

There's nothing I can see in my 98-on version that would indicate improved reliability. TBH, I suspect it's virtually identical to yours. Perhaps climate has a bearing?
They are well-engineered items IMO and I can see some of the manufacturing cost, but electrolytics are what they are and they do age and die - some more spectacularly than others, as you've discovered. I'll be changing them while I'm in there.

Take care to observe polarity when replacing them.

Mike

 

I cleaned up the areas you noted. At this point I think further cleaning may be harmful. Most of the carbon is actually the top surface of the board and you risk damage trying to remove it.
I looked at it with a magnifying glass and the connection running by C721 appears to good but tenuous. The connection to 408 I am unsure of.

Also, there is a small blue/green capacitor?? at the bottom of the burn circle that I am sure is fried. If you can identify it so I could know what to buy I'd appreciate it.

 

Hi Charlie,
I'd be tempted to strip that connection back and jumper. If not, then drop a spot of nail varnish so that it has some support.

The track to C408 may be OK - it looks like residue stuck to the top of it. You can confirm with a mutimeter between it and pin 4 which should indicate a short circuit. If not, then add a jumper across.

The blue capacitor is C720, and bears the marking '104M' which translates to 0.1µF:
Mouser Electronics 0.1uF 100V multilayer ceramic capacitor
810-FG26C0G2A104JRT6

UK URL but there are some pictures & spec:
https://www.mouser.co.uk/ProductDeta...eeUr1jxIgKo%3d

I've added some jumpering points to your pic (attached). With the exception of the possible link to C408, you need some fairly substantial wire as the missing copper is the feed to the throttle motor which is fused at 30A. Suggest 2mm minimum diameter.


I phoned Mouser UK today as they do look like a good source. Apparently no stock is held in the UK and they order from the US
I've messaged them.

 

Hi Mike -

I am ordering parts for this. Finding the correct capacitors hasn't been a problem. I went to mouser.com and they seem to have the right ones. However, finding the right jumper wire is the problem. My best guess from looking at the previous repair wiring is that it is 26 awg. I have found 26 awg on Mouser that is rated at 105c but none are solid copper. The best I can find is 7/32 twisted tinned copper. Will that be ok?

 

Here are the exact capacitors I am ordering from Mouser. I think you should check to be sure I have the correct ones :

1
Nichicon
Mouser #:
647-UHE1H561MHD6
Mfr. #:
UHE1H561MHD6
Mfr.:
Nichicon
Customer #:

Aluminum Electrolytic Capacitors - Leaded 50V 560uF 20%
RoHS Compliant
QuickView


3 Ships Now

$1.06

$3.18

2
Panasonic
Mouser #:
667-EEU-FR1J470
Mfr. #:
EEU-FR1J470
Mfr.:
Panasonic
Customer #:

Aluminum Electrolytic Capacitors - Leaded 63volt 47uF 6.3X11mm LS:2.5mm Bulk Strait
RoHS Compliant
QuickView


6 Ships Now

$0.35

$2.10

3
Panasonic
Mouser #:
667-ECA-1CM221B
Mfr. #:
ECA-1CM221B
Mfr.:
Panasonic
Customer #:

Aluminum Electrolytic Capacitors - Leaded Al Lytic Cap 85C Radial M Series
RoHS Compliant
QuickView


6 Ships Now

$0.25

$1.50

4
Panasonic
Mouser #:
667-EEU-EB1H100S
Mfr. #:
EEU-EB1H100S
Mfr.:
Panasonic
Customer #:

Aluminum Electrolytic Capacitors - Leaded 10uF 50V
RoHS Compliant
QuickView


6 Ships Now

$0.30

$1.80

5
TDK
Mouser #:
810-FG26C0G2A104JRT6
Mfr. #:
FG26C0G2A104JRT06
Mfr.:
TDK
Customer #:

Multilayer Ceramic Capacitors MLCC - Leaded C0G, 100V, 0.1uF +/-5%
RoHS Compliant
QuickView


2 Ships Now

$1.39

 

647-UHE1H561MHD6 560uF 50V Nichicon OK
667-EEU-FR1J470 47uf 63v Panasonic OK
667-ECA-1CM221 220uF 16v Panasonic No
667-EEU-EB1H100S 10uF 50V Panasonic OK
810-FG26C0G2A104JRT6 0.1uF 100v TDK OK
These are all good With the exception of the 220uf which is rated at 85 C.

Here are the part #s for the electrolytic caps I've selected, all Nichicon & rated at 150C, from the UBX range:

1 x 560uf, 50V, 105°C 647-UBX1H561MHL Aluminium Electrolytic Capacitors - Leaded 50volts 560uF 150c 12.5x31.5 5LS
2 x 47uf, 63V, 105°C 647-UBX1K470MPL Aluminium Electrolytic Capacitors - Leaded 80volts 47uF 150c 10x16 5LS
2 x 220uf 10V, 105°C 647-UBX1H221MPL Aluminium Electrolytic Capacitors - Leaded 50volts 220uF 150c 10x20 5LS
2 x 10uf, 50V, 105°C 647-UBX1V100MPL Aluminium Electrolytic Capacitors - Leaded 35volts 10uF 150c 10x12.5 5LS

You need something more substantial than 26awg to bridge across the burnt copper: suggest 10-12 awg. Something around 2-2.5 mm in diameter, and twisted multistrand will be just fine as long as you take care that there are no 'whiskers' causing a short. I had in mind the UK power wiring cable which is a 2.5mm solid core conductor. I'm not sure what your equivalent would be, but I'd ask around the electrical suppliers or an electrician as you only want about 3" in total so no need for a 25m reel...

26 awg is OK for the thinner tracks should you choose to replace the connection running by C721.

Gosh, all these different wire definitions! Someone once said "I love standards: there are just so many of them to choose from"

BTW, the -ve end of C721 should be towards the connector.


Kudos to you for taking this on, and good luck.
Mike

 

Mike -

This one is too tall, it won't fit. 20mm is about the tallest you can go and still get the cover on.

1 x 560uf, 50V, 105°C 647-UBX1H561MHL Aluminium Electrolytic Capacitors - Leaded 50volts 560uF 150c 12.5x31.5 5LS

I take it having an over capacity on voltage is ok, it is under capacity that is a problem? I note that all your recommended replacements have voltage capacity higher than stock capacitors.

 

Actually, looking more closely, I see one of your recommendations is under rated as far a voltage. Are you sure about that?

2 x 10uf, 50V, 105°C 647-UBX1V100MPL Aluminium Electrolytic Capacitors - Leaded 35volts 10uF 150c 10x12.5 5LS

 

I don't know how that 85 degree one snuck in there. I was real careful about size, temperature, etc. I will replace it with this :


Mouser Part #:
647-UPV1A221MGD1TD

6x11mm 105c 220uf 10v

Oh, yes, I made sure all had 5000hr life