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Vito OM646, 2009

Posted: Mon Oct 12, 2026 12:26 pm
by jon5903
Hello everyone,
The Vito 646 engine belongs to a buddy of mine. Donkey years have never failed him. Up until it abruptly stopped working last week. Just died. No beeps, no power outages, nothing. The low fuel pressure was fine, but the high fuel pressure reading was blank, and the crank sensor code was 2045-001. Furthermore, EGR code 2527-004.
I reverse-probed the engine ECU's pins 53 and 77.No reading was found; 750–1200 Ohms would be my expectation. I had the dreaded task of replacing the crank sensor. In any case, unchanged! After verifying the two wires' continuity, I found that the connection between the sensor's pin 2 and the ECU's pin 53 was tight, but the connection between the sensor's pin 1 and pin 77 was open. Accessing the wiring loom is a major hassle. I was hoping to hear from someone who has been in a similar position before I begin opening the loom. Given the similarities in design, it could have been an automobile.
I'm thinking that maybe the best course of action would be to run two additional wires to the sensor. However, similar to CAN wiring, the wires are "twisted" to further complicate matters.
I would greatly appreciate any recommendations.
TIA

Re: Vito OM646, 2009

Posted: Mon Oct 12, 2026 12:26 pm
by maturo99
Does the crank sensor not fit the bill?
After that, synchronisation of the crank and cam sensors.

Re: Vito OM646, 2009

Posted: Mon Oct 12, 2026 12:27 pm
by nub1ru
To reiterate, the crank sensor is the one that typically kills a running engine, not the cam sensor. Were all the fuses checked? If something is fried and blew, the fuses are the first thing to go.

Re: Vito OM646, 2009

Posted: Mon Oct 12, 2026 12:27 pm
by xxxMikexxx
Indeed, the engine will not start if the CPS is malfunctioning. This occurred on our 2007 Vito as well, albeit with the OM642.

Re: Vito OM646, 2009

Posted: Mon Oct 12, 2026 12:28 pm
by maturo99
Climbing the Pennines was definitely out of our league, class 642.
It warmed up and drove again, then stopped, then started again...
After reading this, I went out and purchased a CPS, and the problem disappeared.

Re: Vito OM646, 2009

Posted: Mon Oct 12, 2026 12:28 pm
by xxxMikexxx
It mysteriously and irretrievably stopped working in the Vito. In order to replace the CPS on our drive, I had to call a mobile technician. I found out that MB had a safety recall where they offered to replace the CPS for free on all models of OM642s that were built within a specific date range. For some reason, the W639 was strangely not included in the UK (but it was included in other countries) and MB refused to even make a goodwill contribution.

Re: Vito OM646, 2009

Posted: Mon Oct 12, 2026 12:29 pm
by xxxMikexxx
:D :D :D :D :D