Test Multistage switch for engine speed Flash code: 1x long, 12x short Fault indication: Fault indicated by steady light at EDC indicator lamp Fault path: Multistage switch for engine speed reduction Voltage too high Voltage too low Wrong voltage Effect of fault: No engine speed reduction possible Function: Voltage signals are ascertained via the multistage input (control unit pin 35); their values are determined by external resistor inter- rupters in the EDC operating element Possible cause Line interruption, short circuit, resistor group in the EDC operating element defective (eg cold junction) Test precondition:
EDC control unit disconnected Socket box connected 52 Test Measurement Corrective measures Resistor bank Measure resistance at socket box across pin 35 and pin 13 Setpoint: No engine speed reduction acti- vated: 0.4–0.7 kΩ Engine speed reduction activated: 6.2–11.6 kΩ The fault occurs even if the resis- tance is 0 Ω or ∞ Ω – Check lines – Check plug connections – Exchange EDC operating element