DME 7.8 DME 7.8 0 · 0-201.2P1677

DME 7.8 DME 7.8 0 0-201.2P1677 Engine Compartment Purge Fan Output Stage – Below Limit Diagnosis conditions • Engine running • Battery positive 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 ♦Short circuit to ground ♦Relay faulty ♦DME control module faulty Affected terminals Terminal II/20 Diagnosis/Troubleshooting Work instruction Display OK If not OK 1 Check relays. ♦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 ∞ Ω Repair wiring har- control module to relay wiring harness (DME control Step 3 ness for short to ground module plug). → End. ♦Remove relay ♦Measure resistance between special tool 9637 plug II Pin 20 and ground 1981 P1677 0-201.2 page 1 Printed in Germany – 6, 2002 p1677