Short circuit to B+
1 Check both relays.
1. Remove relays.
2. Connect ohmmeter to terminals 85 and 86.
Display: approx. 75 ohms
2 Check wiring from DME control module, pin IV/4, to relays for continuity.
1. Connect special tool 9637 to wiring harness (DME control module connector).
2. Remove relay stage 1 of coolant fan 1.
3. Remove relay stage 1 of coolant fan 2.
4. Connect ohmmeter to special tool 9637, pin IV/4, and relay slot of coolant fan 1, pin 2 (terminal 85).
Display: 0 - 5 ohms
5. Connect ohmmeter to special tool 9637, pin IV/4, and relay slot of coolant fan 2, pin 2 (terminal 85).
Display: 0 - 5 ohms
If infinity ohms is displayed, check connector X 2/3, pin 21, and check wiring harness for chafing and pinching damage.
3 Perform adaptation.
1. Switch on the ignition.
2. Wait one minute.
Do not press the accelerator.
3. Switch off the ignition for at least 10 seconds.
4. Read out the fault memory.