Hi
The ECU installed on my Daimler is a LNB1410cc/3.
1997, 4.0 engine, automatic transmission.
Can I install a LNB1410bb or any other reference?
What is the meaning of those letters after the 1410?FC, FE, AE, AD, ......
Thank you in advance

At first car would start when cold but wouldn't start easily when hot.
Changed crank positoning sensor: starts easily when cold and when hot but stalls right after with check engine light.
Changed the coolant temperature sensor, no change.
Cleaned throttle body, stalls even more.

 

A I understand it alpha suffixes represent the specific programming for different markets, different options, different build configurations.

There might be *some degree* of interchangability between *some* of the variations....but someone with more precise info will surely chime in soon.

Cheers
DD

 

Doug is right. The suffix identifies the spec and software level. I would expect to see a 3 digit numerical code after the two character letter suffix. Provided the replacement ECU is from the same mechanical spec of vehicle (ie engine size and transmission) and same model year you should be OK. I think there were some changes of emisions spec with model year, so if you don't get the same model year, it could turn on the MIL if your car is a North American spec

You haven't explained why you want to repalce the engine ECU. They are rarely the cause of any engine related problems, unless you have experienced water ingress into the connectors.

 

Andy:
Does the NA and SC use the same ECU hardware? Obviously there is a different setup in the EPROMS, but I am wondering if, for instance, you put your chips in a NA ECU it would run a SC car.

 

At first car would start when cold but wouldn't start easily when hot.
Changed crank positoning sensor: starts easily when cold and when hot but stalls right after with check engine light (before shutting down).
Changed the coolant temperature sensor, no change.
Cleaned throttle body, stalls even more.
At times the transmission check light would even show up.

Both check engine and transmission check light dissappear after restarting the car.

Coils are ok.

The reason why I want another ECU is for testing only, proceeding by elimination.

Cheers

 

Sparkenzap:
All AJ16 engines (X300 and XJS) share the same engine ECU hardware. If the EPROMs are swapped between ECUs are not of the same software level (marked on a label on the EPROM) I suspect it will "reset" the ECU to a condition prior to the end of line PECUS programming step. This will cause the ECU to default to running one of the multiple calibrations programmed into each set of EPROMs. Unless, like me, you have an EPROM programmer, then the only source of EPROMs is out of an ECU, then it is simpler just to swap ECUs rather than switch EPROMs between ECUs.

Jag-Rookie,
I once diagnosed a problem with an X300 which had a throttle potentiometer which failed in such a way as to read maximum throttle voltage. There is an "anti-flood" strategy in the software which disables cranking fuelling if the thrle is fully open. This sofwate was being triggered by the failuire mode of the throttle potentiometer. You really need access to a scan too that can read the throttle potentiometer and other EMS inputs in order to diagnose your starting problem. Such a tool probably wouldn't cost you any more than an ECU from a breaker's yard and could be very useful in thefuture.

 

I think Sparkenzap is asking that question on my behalf.

My ECU might have a problem and a swap-out would be helpful to confirm. I'll start a new thrad rather than hijack this one

Please keep and eye open for it !

Cheers
DD

 

XJR ENGINEER;


This is a topic that interests me a lot.
Does this mean that if I use the EPROMS from a XJS Aj16 ECU and install them on a X300 ECU, the X300 ECU will work on the XJS?

Reason I ask is because the XJS ECU's cost a lot more than the X300. If all that an owner has to do on a XJS ECU with connector damage is remove the EPROMs and place them on a X300 ECU it would be good to know.

 

hi people
before I lose your attention, attached is a pic of the label on the ECU.
Can you translate what is shown there?
Thanks

 

Spikepaga,
In Europe it isn't possible to run an XJS on the ECU from an X300 because the ECU has been synchronised to the security ECU present in the European X300. US spec X300s are different to Europe, so I don't know if the same is true.

jag-rookie
The part number on the label that you have shown is incomplete LNB 1410 CC/3--. The PECUS system is used at the end of the production line to select which set of maps are used in the ECU software. There should be another label on the ECU which repeats the same part number but the last two digits, shown as dashes on the label that you photographed, are included. This label is only stuck on the ECU after the PECUS programming has been completed, and has the words "JAGUR PECUS" printed on the bottom of it. The 3 digit number starting with a 3 defines the spec of the vehicle. If you replace the ECU you should aim to do so with one with the same 3 digit number.

I also note from the date code that the ECU was manufactured in wk 15 of 1997. Ideally you should therefore aim to replace it with an ECU from a 1997 model year car. The car may drive fine with an ECU from an earlier model year, but it may turn on the MIL, but then again you may be lucky and it may not.

 

Thanks for your reply!

Because of the rarity of the XJS AJ16 ECU's, I have 4 of them with totally different numbers. One is from California which i imagine means its got a different program .

Who would be able to remap the EPROMS in all the units to make sure they all fit my car? Is that a service you provide?

Thanks for taking the time to answer

 

I think Jaguar sold the same spec cars to all 50 states, even though it might have been possible to get away with higher emissions and less diagnostics in some states at the time the cars were made, but the extra complexity could not be justified.

I can reporgramme certain changes in the ECUs for AJ16 engines. If you justwan tthem as spares, I suggest that you just try them and see if they sent any fault codes. You may have to have a throttle adaption performed each time you "introduce" each ECU to the car for the first time.

 

Thanks for your reply. I have tried all my spare ECU's briefly and no lights and the car seems to run fine. Perhaps all US ECU's are interchangeable .