BMW offers the following cautions that should be observed to protect the DME system and components:
EXTERNAL SAFETY PATH (EML)
The external safety path must be checked anytime a component of the EML throttle by wire system is removed or adjusted.
- Read all fault codes from the EML memory before checking the external safety path. This will require the BMW Diagnostic tester or equivalent.
- Turn the ignition switch to OFF . Unplug the EML connector. The EML connector is grouped with the DME engine connector and the diagnostic connector on the left side of engine compartment near the fuse box.
- Install the EML testing adapter 12 7 010 or equivalent to the EML connector inline. Make sure all connections are tight.
- Turn the knob on the tester to the left position and start the engine. Adjust the engine speed to 2500 rpm with the tester knob.
- Depress the brake pedal. The engine speed should drop immediately due to the overrun shutoff provision.
- If the engine speed does not drop immediately, check the EML system for faults. If the speed does drop immediately, the EML external safety path is functioning.
- Shut off the engine and remove the tester. Reconnect the EML connector and erase any fault codes from the EML control unit.