Lamborghini Engine Fault Code Removal

Fig 1. Diablo LIE Computer

The LIE computer on Diablos (and all later cars) accumulate a detailed history of numerous measurements of a cars performance over time. Things like the max RPM's the car has experienced. The max temperature of oil, water etc. It also contains a detailed list of engine code errors. Even if the check engine light goes out the code is still retained in the LIE computers memory. It's not clear for long. It's probably a function of how many errors have appeared over time. In any event the information is there for many stop/start cycles of the engine.

If you have overhauled the engine or corrected some other engine problem some people like to clear out these error codes. Start with a clean slate so to speak. This can be done using a jumper socket to the LIE computer.

Before you even think of doing this, understand that you are doing so at your own risk. A wrong jumper may seriously damage the LIE computer. This is an expensive part to replace in these cars.

Also it looks like different Diablo's over the years have different sockets to reset the computer error codes. For all Diablos the LIE computer is located behind the passenger seat.

Diablo VT's Built in 1997,1998 and 1999.

Diablo VT's built in 1997, 1998, and 1999 have a white "Molex" type of socket that is used to hook the LIE computer up to a special socket Lamborghini supplies to clear the LIE computer memory. It's part number is #6134045. However it is simply a one wire jumper as shown in Figure 2. Look carefully at the notch on the socket and figure which of the two pins to short in the car socket.

Fig 2. LIE Computer Reset Jumper for 1997, 1998 and 1999 Diablo VTs.

To clear memory Lamborghini says first remove the cause of any engine errors if they exist. Then with the ignition in the "STOP" position (I assume this means off position), insert the connector. Then turn the ignition to "MARCIA" (I think this means on, but not started). In this way the errors are deleted. Turn off ignition then remove jumper.

Early Diablos

Early Diablos (1990 to 1994) have a round socket quite different than the one above. To reset the LIE computer in these cars you need a three pin connection. The three wires are connected together (Fig 3). While again I am sure Lamborghini supplies one, it is possible to make one yourself. In order to reset the LIE computer you need to short together pins 7,9 and 13. These pins are marked on the socket itself. With a light and magnifying glass you can see that the socket holes are numbered 1 to 14. Be real careful to jumper the right pins together! A wrong connection could blow the whole LIE computer.

Dave (see below) has recently sent me three photographs (figs 6,7 & 8) of the corresponding jumper for a 96 Diablo Roadster. If you look at the clip from the top. Jumper wires connect pins 7,9 and 11 (with no pin in position 10 for orientation).

12	11	10	9	8	7
1	2	3	4	5	6

Note jumpers like these can be bought as a Lamborghini part for about $14. It may be an easier way to go for many people. They can be ordered from a number of knowledgeable suppliers, e.g. Nelson Lamborghini, OH. Ask for Glenn 800-609-9595.

Thanks to Dave Ayres, Orange CA., for this information on the above 3 pin connectors.


Fig 3. Home made reset jumper	Fig 4. carefully insert jumper	Fig 5. Close-up of jumper installed


Fig 6. LIE socket in 96 Diablo Roadster	Fig 7. 96 Diablo Roadster Socket	Fig 8. Close-up of 96 jumper

I do not have information about a jumper for later cars. For these cars, the OBDII system can be used to reset most codes that trip the check engine light anyway. See OBDII Codes.