03-11-2012, 04:06 PM
Location: Gravesend, Kent, UK
Join Date: Mar 2011
Mein Auto: BMW 735Li E66
New DME required???
I have a 2003 E66 735Li N62 engine which is in permanent 'limp home' mode i.e. "Engine Fault - Reduced Power".
The fault started as an intermittent fault about 2,000 miles ago (i.e. it only occurred when the car had been standing overnight and would clear after a couple of engine restarts) and was worse in cold weather. An OBD scan threw up the following generic DTC fault codes:-
'P1065 - Variable valve timing - timeout, no signal - Can data bus malfunction'
'P1061 - Variable valve timing, bank 1 - limp home mode - circuit malfunction'
The fault condition is now permanent and so I had a friend with BMW DIS v.57 diagnostic software do a scan and here is the report:-
Valvetronic Timing Control – No Communication Possible
CAN-FFFF-Can - Communication Fault
Determined Possible Causes:-
Possibility rating indicated by stars (5 being max)
System Analysis B6131_60113
Analysis of the bus fault showed that the DME did not participate, at least temporarily. On no account should the DME be replaced due to sporadic communication faults.
Other possible causes:-
Check for loose or dirty connectors / replace connectors
As far as I can interpret the report, the VVT ECU is not communicating with the DME. The VVT ECU was replaced 10,000 miles ago for a different fault (VVT ROM error - internal fault) and I have checked and cleaned (with contact cleaner) all of the connectors and pins on the VVT ECU, the DME and the Integrated Supply Module and all seems fine.
I am thinking that the DME itself is faulty but because of the cost of these units I want to be sure before parting with my money. Is there any way the DME can be bench tested off the vehicle? I would love to hear from any BMW Techs out there.