DME 7.8 DME 7.8 0 · 167 Fuel pump relay output stage - open circuit

DME 7.8 DME 7.8 0 167 Fuel pump relay output stage - open circuit Diagnosis conditions • Engine started Note! The triggering wire for the fuel pump relay, terminal 85, is moni- tored. Possible fault cause ♦Fuel pump relay ♦Open circuit ♦DME control module Affected terminals Terminal IV/10 Diagnosis/troubleshooting Work instruction Display OK If not OK 1 Check fuel pump relay ♦Remove fuel pump relay Approx. 75 Ω Replace fuel pump ⇒ Step 2 relay ♦Measure resistance between Pin → End 85 and Pin 86 2 Check wiring from DME ♦Connect special tool 9637 to 0 - 5 Ω Check plug connec- control module, Pin IV/10, wiring harness (DME control ⇒ Step 3 tion X 2/3 and wor- to fuel pump relay for con- module plug) ing harness tinuity → End ♦Remove fuel pump relay ♦Measure resistance between special tool 9637, Pin IV/10, and fuel pump relay slot, Pin 6 (terminal 85) 3 Replace DME control module ⇒ Step 4 4 Perform adaptation ♦Switch on the ignition → End ♦Wait one minute ♦Do not press the accelerator ♦Switch off the ignition for at least 10 seconds ♦Read out the fault memory 2472 P1124 0-112 page 3 Printed in Germany, 2000 p1124