I have a ‘96 XJ6 4.0l straight 6 with a no start problem.
Having went through a list of checks and part changes I am at the stage of replacing the ECM.
I have the model number as LNB1410AC.
Any that I have found online have a different last 2 letters in the model number.
My question is if the last 2 letters being different matter and will it be compatible with my car?
Thanks In advance, Alan

 

https://www.jaguarforums.com/forum/x...amming-287665/

 

Do you have starter rotation ?

The split in half point in the starter system is if the large starter solenoid relay clicks with your finger on it , other relays will click by sound at the same time so must use finger

You can use a medium gauge jumper wire with blade type wire ends to command the starter to engage , socket 3 to 5 , this verifies the power side as the solenoid and starter motor funtion along with the heavy battery power to it is good

The other half is the enables in which ECU is one but the summation point of the enables is the body processor module

There is a small relay in the corner of the right engine bay fuse box that must click ( again with your fingers ) to power fuse # 10 , 12 , 14 , and 16 for the engine ECU , this small relay can be swapped with the left engine bay fuse box ( only runs the car horns )

To test this relay by yourself have key in run position and remove relay and it should click in your fingers back to open

Let us know what you have done and your findings

There is a inertia / crash switch that can trip for no reason and you can jumper the 2 white wires with a paper clip , low current

You can also directly power the fuel pump same socket 3 to 5 on the relay

You must get 3 clicks on your finger of the fuel pump relay , On 3 seconds - off - On

The fuel injectors to open , 1/2 your engine sensors , and power going back into ECU is the large # 5 ECU controlled relay that must click closed again with finger , swapping option is a headlight , fog , or A / C clutch of the same part #

There is a small 5 amp fuse as # 10 right heelboard fuse box that is the " control " power to close fuel pump relay and it's relay in the corner of the fuse box must click closed to power fuse your finger on it , again a test is key in run and remove relay , same swapping with left engine bay fuse box

Getting around to ECU swap there is a " match " of the ECU and throttle position null value that is luck of the draw if a replacement matches which opens a can of worms in idle range ( it may get you around engine fully starting up issue ) plus if the R - 493 TSB ( sticker on ECU and changed Eproms ( maps ) inside ) has been done on yours and the replacement

If you're in California there is specific ECU #s to pass your emmissions smog test