Engine Controls - VDU Reads 'DME Control Unit Not Found'
90bmw08Group 13 Fuel System
Bulletin Number 13 05 90 (3056) Page 1 of 2
Woodcliff Lake, NJ April 1990 Service Engineering
SUBJECT: DME/Diagnostic Module Testing
MODELS: 5 Series (E34) (produced 1/90 thru 5/90)
Situation: The above listed vehicles may encounter the following problems when using the BMW diagnostic module:
Fault 1
When attempting to establish the diagnostic link, the VDU reads "DME control unit not found".
Fault 2
DME fault code # 40 A/C compressor sets (erroneously) in DME fault memory.
Cause: The new IHKR II system causes interference with the DME system during initial system self-testing.
Solution: Fault 1
Remove fuse F9 from the front power distribution box before turning the ignition switch ON. When the diagnostic link is established, reinstall fuse F9.
Fault 2
Disregard DME fault code # 40 if no air conditioning complaint exists.
Identification: The new IHKR II system can be visually identified noting the following changes in the IHKR control panel:
Important
Note: At present the above situations cannot be corrected by replacement of the DME or the IHKR II control units.
Warranty
Status: Information only.