Hi, I have a 55 plate Focus zetec 1.6 71,000 miles. Whilst driving yesterday there was a loss of power & " acceleration reduced " appeared in the message centre. I pulled over, switched engine off then restarted & got home fine. Same thing happened today, car was fine for about 3 miles then " engine system fault " followed by " acceleration reduced " but got home ok. I've scanned for fault codes & U0001 appeared which is " high speed CAN communication bus ". I've been busy googling possible causes today & it seems that a faulty instrument cluster could be a possible cause. Can anyone please advise as to whether this is the likely cause & how would I go about fixing it. I've read that Ford charge £500+ to fix the problem, can't afford that sort of cash especially as I forked out £360 for a new clutch less than 2 weeks ago. Incidentally this problem arose just after I'd put some redex petrol cleaner in my car when filling up so don't know whether that may have been a factor.

I had a problem with my IC (Instrument Cluster) a couple of months ago. System light on, various combinations of other lights on, and immobiliser active so car would not start. It was just one bad solder joint on the IC, and other people have had exactly the same fault, though symptoms vary a lot. My car is a 56 plate TDCI. The fault was one of the CAN bus pins where the connector was soldered to the pcb.

The real diagnostic check is to measure the resistance between the two CAN bus wires with the ignition off (wait at least 30sec after turning off). Pins 6 and 14 on the main diagnostic connector (where the scanner goes) are this CAN bus. Google should show diagrams of this connector with the pin numbering.

It should be 60 ohms pretty close. There is one 120 ohm terminating resistor in the main ECU module, and one in the IC, these are the two ends of the main high speed CAN bus. If both are in circuit you will get 60 ohms. A break in the line will read 120 ohms, and a bad joint in the line will give variable readings between 60 and 120 ohms. Tapping the fascia around the IC may cause the readings to vary. There are a couple of plugs in the CAN bus, one in the main (engine bay) fuse box, and one at the bottom of the front passenger door, behind the trim. Unplugging either of these will disconnect the ECU from the IC and diagnostic connector, so the CAN bus resistance should go to 120 ohms solid if the IC is ok, or may go very high if the IC is faulty.

I have made a PDF of how I found & fixed this nasty problem.

Hope this is of some help. Keep away from main dealer garages if at all possible!!!

Peter.

 

http://www.fordownersclub.com/forums/applications/core/interface/file/attachment.php?id=40491

Edited July 19, 20169 yr by Tdci-Peter
correct link

Thanks very much for your reply Peter. I took the car to a local garage last Saturday & they hooked the diagnostic machine up to the car & it came back as an instrument cluster problem. The car has been driving fine since then until today when it wouldn't start when I was leaving work. Luckily it eventually started but I'm not taking any more chances, I'm dropping it off at the garage tomorrow & they're taking the cluster out for me so I can send it off for repair.