DME 7.8 DME 7.8 0 · 0-61P0418

DME 7.8 DME 7.8 0 0-61P0418 84 Secondary air injection pump - open circuit Diagnosis conditions • Engine running • Battery voltage greater than 7 V Possible fault cause ♦Wiring harness ♦Relay faulty ♦DME control module faulty Affected terminals Terminal III/11 Diagnosis/troubleshooting Work instruction Display OK If not OK 1 Check voltage supply for ♦Remove relay of secondary air > 11 V Repair voltage sup- relay of secondary air injection pump ⇒ Step 2 ply injection pump, terminal → End ♦Measure voltage between Pin 7 86 and ground ♦Switch on the ignition 2 Check relay for second- ♦Remove relay for secondary air Approx. 70 Ω Replace relay ary air injection pump injection pump (at 25 °C) → End ♦Measure resistance between relay Pin 85 and Pin 86 3 Check wiring from DME ♦Remove connector of electric 0 - 5 Ω Repair wiring har- control module, Pin III/11, change-over valve ⇒ Step 4 ness to relay of secondary air → End ♦Measure resistance between injection pump for conti- DME control module Pin III/11 nuity and relay of secondary air injec- tion pump 4 Replace DME control module ⇒ Step 5 5 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 2665 P0418 0-61 page 1 Printed in Germany, 2000 p0418