Citroen Evasion/ Synergie - Engine diagnostic lamp is lit | HELLA

If the engine diagnostic lamp signals that the engine is losing power, this may be caused by the brake-light switch being wrongly positioned or incorrectly attached. It is possible that excessive tolerance may enable the switch to shift within its support, with the effect that the electronic control unit receives “acceleration” and “braking” information simultaneously. Since it is unable to process both of these simultaneously, it causes the engine to carry out a kind of “emergency running function”.

In this situation you need to correct the position and attachment of the brake-light switch. Please do this by following the disassembly and reassembly instructions from the vehicle manufacturer.

Check brake-pedal switch: (see Figure1).

1 & 2 (ballpark figure brake pedal released) ∞Ω

1 & 2 (ballpark figure brake pedal depressed) 0Ω