I have a 2003 BMW 735Li E65 with the N62 32 valve V8 engine. The engine fault light comes on when the engine has been started from cold. I did a OBD scan and got the following fault code: -
'P1065 - Variable valve timing - time out, no signal, CAN Data Bus error'.
I clear the error and reset the light and the fault doesn't re-occur until the next cold start.
I fitted a new Valvetronic (VVT) ECU & voltage supply module 10,000 miles ago to cure a different problem with the valvetronic system so I'm hoping that's not the problem. The problem has only just started and the weather here in the UK has been very cold (near freezing) the past few days. Could the problem be temperature related?
There are 38 different BMW fault codes relating to the valvetronic system alone. I really wish I had bought a Mercedes!
Data Bus error tells me it's a problem with the ECU communicating with the VVT system. "No signal' also says the same thing.
Look for broken wiring. Look for loose connectors. Look for frayed wires at the connectors. Look for contaminated connections and connectors. Anything that can keep the system from communicating with its component parts.
December, 17, 2011 AT 11:42 PM
Do you mean the VVT ECU or the main engine management ECU? Thanks.
December, 18, 2011 AT 12:02 AM
Both. Check the VVT controller first. Then move to the main ECU.
December, 18, 2011 AT 9:07 AM
Thanks. The only time the wiring has been disturbed was when the VVT ECU was replaced and the car has been running fine since then for 10,000 miles. I'll check all the wiring and clean all the connector blocks with an electrical cleaner aerosol.
December, 18, 2011 AT 6:59 PM
Ok. Let us know if that makes any difference and we'll go from there.
December, 19, 2011 AT 2:39 PM
Thanks - I won't get a chance to do it until after the Christmas Holiday but I will let you know how it goes. Happy Holidays!
December, 19, 2011 AT 6:08 PM
Ok. Festive Yule. Look forward to hearing back from you.
December, 21, 2011 AT 1:04 PM
Thanks. The problem hasn't re-occurred for the last few days but I will still carry out an 'inspection and clean' as soon as I can and get back to you.
I have asked a separate question with another donation. I don't know if it will get to you or another expert. I am new to the '2CarPros' website and assumed that new questions had to be posted separately.
December, 21, 2011 AT 6:16 PM
It is appreciated whn they do. Most likely another expert will grab it.