Diablo engines are very reliable. They can take a tremendous pounding and are for most of us driven far below their capabilities in terms of power demands. Nevertheless from time to

Figure 1. Front check engine lights in a Diablo.

time things can go wrong or need a minor adjustment.  The computer signals if something is wrong with the engine by turning on the R or L engine warning light. 

These two lights correspond to the right and left bank of cylinders of the V12 engine.  Rather than acting as a simple warning light however, there is a diagnostic test to then find out what the problem is.

The engine computer (the "LIE control unit as Lamborghini calls it), is able to acknowledge and memorize engine failures relating to the many sensors surrounding the engine. If it picks up a problem it simply turns on the L or R check engine light.  If the failure was only temporary, the LIE system switches off the check engine light after 2 minutes. The error code is however stored by the LIE computer.   To retrieve the error code. With the engine off, switch the ignition on off 3 times to the first position (i.e.. not far enough to start the engine, but enough to light up the front instrument panel). The fourth time the key is switched to the on position the check engine light L or R will flash with a code corresponding to the problem detected by the cars engine computer.  The table below explains what these codes mean:-

Number Of  Flashes   Error Indication 1 Lambda sensor inactive 2 Lambda sensor detected weak fuel mixture 3 Lambda sensor detected rich fuel mixture 4 Timing sensor 5 Engine speed and TDC sensor 6 Engine speed and timing sensor signal wrong sequence 7 Air pressure sensor 8 Battery voltage 9 Coolant temperature sensor 10 Not used 11 Intake air temperature sensor 12 Throttle potentiometer 13 CAN communication link failure 14 Not used 15 Not used 16 Not used 17 Catalyst system efficiency 18 Lambda sensor efficiency 19 Misfire detected 20 Misfire detected 21 Carbon filter washing solenoid valve 22 OBDII system failure 23 OBDII system failure