DME 7.8 DME 7.80 · 167 Fuel pump relay output stage - above limit

DME 7.8 DME 7.80 167 Fuel pump relay output stage - above limit Diagnosis conditions • Engine running • Battery voltage greater than 7 V Note! The triggering wire for the fuel pump relay, terminal 85, is moni- tored. Possible fault cause ♦Fuel pump relay ♦Short circuit to B+ ♦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 V Repair wiring har- control module, Pin IV/10, wiring harness (DME control ⇒ Step 3 ness to fuel pump relay for module plug) → End short circuit to B+ ♦Remove fuel pump relay ♦Measure voltage between spe- cial tool Pin IV/10 and ground ♦Ignition on 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 0-112 page 2 2472 P1124 p1124 Printed in Germany, 2000