DME 7.8 DME 7.8 0 · 0-200P1674

DME 7.8 DME 7.8 0 0-200P1674 497 Engine compartment purge fan output stage - open circuit Diagnosis conditions • Engine running • Battery voltage greater than 7 V • Engine compartment purge fan switched on once • Engine compartment temperature greater than 75 °C • Front and rear lids closed Note! The triggering wire for relay terminal 85 is monitored. The rear lid may be opened to speed up the warming process. In order to proceed with the diagnosis, the rear lid must then be closed. Possible fault cause ♦Open circuit ♦Relay faulty ♦DME control module faulty Affected terminals Terminal II/20 Diagnosis/troubleshooting Work instruction Display OK If not OK 1 Check relay ♦Remove relay Approx. 75 Ω Replace relay ⇒ Step 2 → End ♦Measure resistance between Pin 85 and Pin 86 2 Check wiring from DME ♦Connect special tool 9637 to 0 - 5 Ω Repair wiring har- control module to relay wiring harness (DME control ⇒ Step 3 ness for continuity module plug) → End ♦Remove relay ♦Measure resistance between special tool 9637, plug II Pin 20, and relay slot, Pin 2 (terminal 85) 1981 P1674 0-200 page 1 Printed in Germany, 2000 p1674