This test module serves the purpose of examining the foot controls, more precisely the simultaneous operation of the accelerator and brake pedals while driving, in order to recognize a mechanically snagging accelerator pedal.
The fault code is set in the DME control unit when a constant driver's choice via the accelerator pedal is detected for at least 2 seconds (constant means: Change in pedal angle less than 0.4°) and in addition the brake pedal (brake light switch) is activated for 1 second.
The vehicle reacts as follows for as long as the constant driver's choice with the brake light switch active is applied:
The DME control unit reduces the driver's choice by 0.4° per 10 msec and deactivates fuel injection.
Perceivable effects: like taking foot off accelerator pedal
- Inertia fuel shut-off while driving
- Loss of power output
- Increased, constant engine speed and/or mechanical snagging of accelerator pedal
Engine speed ≥ 1280 rpm
Speed ≥ 7 km/h
Driver's choice ≥ 12° pedal angle
No fault code entries in the DME control unit for following assemblies:
- Pedal position sensor
- Brake light switch
Consequently:
Warm-up phase (engine cold) and increased idle speed as the result of electric loads cutting in, do not result in fault code entries.
Only in the case of express customer complaint about increased, constant idle speed (higher than 1280 rpm) and/or mechanical snagging of the accelerator pedal in conjunction with a corresponding fault code entry should the pedal position sensor be replaced.
Entry of the fault code alone does not justify component replacement.
If this fault occurs more often the customer's attention should be drawn to the problems of simultaneously operating the accelerator and brake pedals.