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
Important safety notice
The following technical information and tips for practical use have been set up by HELLA in order to offer professional support to automotive workshops in their daily work. The information available here on this website is only to be used by appropriately trained specialist staff.
The reprinting, distribution, reproduction, exploitation in any form and disclosure of the contents of this document, even in part, is prohibited without our express written approval and indication of the source. The schematic illustrations, figures and descriptions are for explanation and presentation of the document text and cannot be used as a basis for installation or design. All rights reserved.