DME 7.8 DME 7.8 0 · 0-78P0482

DME 7.8 DME 7.8 0 0-78P0482 591 Fan output stage 3 - open circuit Diagnosis conditions • Engine running • Battery voltage greater than 7 V • Engine temperature greater than 108 °C • Vehicle speed greater than 25 km/h (15 mph) • Engine speed more than 1000 rpm Note! The triggering wire for relays stage 3, terminal 85, is monitored. Possible fault cause ♦Open circuit ♦Relay faulty ♦DME control module faulty Affected terminals Terminal IV/31 Diagnosis/troubleshooting Work instruction Display OK If not OK 1 Check both 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 Repair wiring har- control module, plug IV wiring harness (DME control ness Pin 31, to relays for conti- module plug) → End nuity ♦Remove relay stage 3 of coolant fan 1 ♦Remove relay stage 3 of coolant fan 2 ♦Measure resistance between 0 - 5 Ω special tool 9637 plug IV Pin 31 and relay slot of coolant fan 1 plug Pin 2 1908 P0482 0-78 page 1 Printed in Germany, 2000 p0482