Just purchased 2005 XJ8 L. Previous owner had problems with one injector not firing, although lead had continuity back to ECM. So, he tried to replace ECM. Replacement ECM has been installed to some point. Car starts, key works, but Instrument Panel alternately reads out CONFIG E and RESTRICTED PERFORMANCE. Car is restricted to running under 3000 RPM. Engine check light is on at start but can be reset using simple diagnostic tool supplied to me with car. Supplier of replacement ECM believes mechanic who installed the replacement ECM did not understand what he was doing. I reckon I can sort this out. Through this forum I have acquired Technical Bulletin 1-186 and the IDS-SDD-JLR Manual. I have read through this helpful post: https://www.jaguarforums.com/forum/s...c-fixed-67541/. I think I should follow the solution proposed there. But would love confirmation. I have ordered a JLR Mongoose and SDD software. I am in Hawaii, so no dealer on this island, and mail is slow, so I am waiting for those parts. In the meantime. all this is new to me, so if anyone has any thoughts on how I might proceed once I have the software, I would be grateful for any pointers. (By the way I think that one injector might still not be firing; I will follow up on that once I have the car operating properly.) I do have a simple battery charger I can connect while reprogramming.

 

You are not quite in the right section of the forum. This is for the x350 (XJ) but is probably very similar.

Good luck hope you can sort it out.

 

I think for a 2005 XJ8 L, the original poster is in exactly the right place.
I wish I could help. I wonder if the original ECU is available?
Pete M

 

Can you give me a link to the right section of the forum? Want to follow the right path, but have to admit I am baffled!

 

https://www.jaguarforums.com/forum/s...ed-v8-x200-15/

 

Is it just me? Is this an S-Type?
Sure looks like an X J 8 L to me.
Someone get on board and help this poster, please.

 

Yes, original ECU is here, but supplier of replacement ECU told former owner it had problems. However, said replacement ECU supplier would have an interest in saying this, so not convinced, especially since the intermittent DTC code P0351 (ignition coil malfunction) persists with the new ECU in place, which the new ECU was supposed to fix, although the new ECU does throw the config E error so jury still out, but I'm suspicious the ignition coil malfunction will not be fixed by the ECU replacement. Seeing that Engine Check comes on during acceleration and at startup, I think we have an intermittent loose wire, which since it is intermittent, may explain why continuity from coil to ECU tested okay, which led the mechanic to think it was an ECU issue not a wiring issue. This was all before I acquired the car. Once I get the ECU configured (Mongoose has been shipped) I will revisit the P0351 issue. There is also a P1647 (heated oxygen sensor 1, bank 2, control malfunction) DTC being thrown; I have no idea what this is. I figure the DTC's should be run to ground after the ECU is properly installed. Again, any thoughts/insights welcome. The car is an engineering marvel, just amazing. We'll sort this out I'm sure.

 

Pete had the right thought, I would also put the original ECU back in to restore the original condition. Using SDD to solve the problem is the right way, make sure that the battery is well charged and also a power supply is connected, preferably with not less than 25A charging power.
When the initial state is restored, I would visually check the cable connection from the ECU to the coil (as far as it is accessible) and open and examine the connectors. If there are no obvious errors to be found there are P0351 related pinpoint tests in the WSM to be found, it should be worked through.
If all this does not lead to the elimination of the error, you can still lay a parallel cable from the ECU to the coil.
The P1647 indicates, among other things, a defective lambda sond heater. The error can occur completely independently, I would not pay attention to it at first.

Fritz

 

Hi Perfwise,
My thoughts are that I would stick with the original ECU, and troubleshoot that with the help of the experts here (I'm not one of them!).
A good scanner is vital for faultfinding. I have the iCarsoft LR V2, which is plug and play. The Mongoose setup is more complicated.
Reconfiguring an ECU is definitely non-trivial, even to those who are experienced. The most common cause of ECU problems is a blocked aircon intake duct drain. Water overflows, and ECU is underneath. There are lots of threads about this. Any obvious damage or corrosion to the ECU plug and socket?
Hope this helps.
Regards
Pete M

 

The original ECU looks pristine:, see below. I will reinstall this and give it a try. Thanks also to flatsix: I think you are right about what to do. Will report here after trying the original ECU; then if that works, will start new threads on any remaining issues.

 

A corrupted VID block is not a good thing.
Swapping parts without understanding the network is dangerous.

 

Thanks for these documents. Very helpful.

 

OK, so small issue restoring the original ECU. The bolt head is stripped and my T30 socket won't grab. The joys of buying a used car. I will need to get a diamond bit on a Dremel and clean it up, hopefully can get it working. I don't have these tools here, since sold mine when moving from Australia due to charging voltage difference between countries, So need to re-acquire. Or do you just try to drill it out? Thoughts on this appreciated. And i must order a new bolt in any case, what's the best way to do that? Meanwhile, I will wait for the Mongoose to arrive here, and reprogram the VID into the ECU. Docs provided to assist with this by mototrcarman much appreciated. Thanks all for your help so far, very much appreciated, no Jaguar dealer on this island. Shipping to Honolulu for service US$1000 round trip plus dealer service charges.

 

Hi Perfwise,
I seem to remember that the ECU bolt is not a normal 6-lobe torx, but a 5-lobe security torx, so you need a special bit. I think they are available from tool suppliers.

Pete M

 

Thanks, yes, it's 5-tooth socket, I do have that bit, but no joy.

 

Tamperproof TORX PLUS.

 

It cannot be stressed enough that you must have a constant power supply of at least 25 amps. A regular battery charger will decide your battery is fully charged and may turn off or reduce to trickle charge in the middle of programming. The ECM can be recovered but it is not for the faint of heart!

 

I am worried about this. Most chargers seem to claim to be "smart" and will revert to trickle charge automatically. Can you recommend a battery charger or type of charger which gives the operator full control? Also, jamming 25A onto a fully charged battery seems to me would boil the water pretty soon. I don't understand how to manage this safely. So need some recommendations/procedures that will work.

 

One similar to the one below works well. There are many types available. It is a smart charger until you switch it over to constant voltage. The voltage is adjustable so can be set to the range Jag wants during SDD use/programming. Never had a problem with battery while connected and have had it hooked up for long stints while working on the system. Mine is a 2004 so I could have gotten away with only 25 amps although I have seen over 30 amps being drawn during the SDD initial testing sequence.
If you ever intend to get a later model of Jag - including the 358 - you should get the 55 amp model, which current value Jag specifies. Not sure of the actual year the higher amps are recommended - could be 2005 on - I do not remember the date for the higher requirement.
Others may chime in with more power supply recommendations.

 

Update: I have purchased a PowerMax 35Amp charger for US$113. Called PowerMax, and they assured me that even in trickle charge mode, charger will respond up to max amps of 35 if load is placed on battery, so no need to set anything, should just work. Bought from ebay, delivery rapid.

Still waiting for JLR Mongoose from OBDII Shop: way overdue, company claims COVID delays; all I can do is wait.

I solved the stripped T30 bolt as follows: removed the plastic shield around the wiring harness by springing the clips with a small screwdriver, which can be done with harness attached. This gives access to the bolt, which I could then remove with a pair of channel lock pliers and some patience, many turns of about 1/4 turn each. Then tried the original ECU. Car would turn on but not start: conclusion is key is married to the replacement ECU. Put that back in and I am mobile again, but still in restricted mode. Waiting for the JLR Mongoose.