Operation CHARM: Car repair manuals for everyone.
Hosted by mcallihan.com

E1 Checking the Main Relay

E1 Checking the main relay

Tools:
- Multimeter
- Jumper lead with crocodile clips 83 93 894.

1 Disconnect the control module and the mass air flow sensor. Peel back the cover on the control module connector. All readings should be taken from the rear of the connector.

Check whether pin 11 of the connector is connected to ground.

2 Switch on the ignition.

3 Use the jumper lead with crocodile clips (83 93 894) to connect pin 21 (yellow/white; GL/VT) of the control module connector to ground. Check the operation of the relay by ascertaining whether voltage is present across pins 9 (brown / white; BR/VT) and 11 (black; SV) of the control module connector.

If no voltage is present, gain access to the relay by removing the sill scuff plate, weatherstrip and carpet.

Check for voltage across pin 30 (red; RD) of the relay and ground and across pin 86 (red; RD) of the relay and ground.

If no voltage is present, check the wiring between pin 30 (red; RD) and the positive terminal and between pin 86 (red; RD) and pin 30 (red; RD).

If voltage is present, use jumper lead 83 93 894 to connect pin 85 (yellow/white; GL/VT) to ground. Check for voltage at pin 87 (brown/white; BR/VT) and pin 87b (brown/white; BR/VT) of the relay. If no voltage is present, fit a new relay.

If voltage is present, use jumper lead 83 93 894 to check the brown/white (BR/VT) lead from pin 87 of the relay to pin 9 of the control module, the black (SV) lead from pin 11 of the control module to ground, and the yellow/white (GL/VT) lead from pin 21 of the control module to pin 85 of the relay.

Check for voltage at pin 2 (brown/white; BR/VT) of the mass air flow sensor. If no voltage is present, check the wiring up to pin 87b of the main relay.