How how how did you come come come to that that that fault code?
Ha ha ha just messing with you.
Did you google that term?
It seems to refer to an electro-mechanical valve of some sort.
I'd start with this one:
It controls the EGR.

The other one is:
Boost control valve, located behind right front wheel. Controls waste gate on turbo to regulate boost.
That's all I can think of right now.
If anyone else can think of another....... ?
Cheers.



Mercedes Vito. Making mechanics out of owners since 1998!?

 

ha Cheers Devito

My friend is a mechanic and he has a Snapon Solus Pro OBD scanner.

Motor is actually in limp mode. Instrument panel is knackered too. The EDC LED has been stabbed with a screwdriver it seems and the connecting ribbon inside to light the odometer is kaput too.

Anyway, the codes were:

P1622 Electric Switchover Valve (Y75)
P0703 Stop Lamp Switch (I've ordered one as it was broken)
P1403 EGR (But no EGR present)

I've found the boost control valve and swapped it out to check but no difference. Maybe the 2nd unit I tried was duff too?

That pic you've added is on my motor tied to the top of the bulkhead. I had assumed it was a vac to the EGR (But like I say, it's been removed - If it ever had one, but I'm guessing it did that's why the code has thrown.) Maybe I'll plug it too.

 

I plugged the vac tube on my EGR.
Didn't get a fault code.
Step by step you will cure your bits faults. It ain't rocket science and with the help of a lot of experienced Vito owners on this forum it'll be ?
(A piece of cake) Ha ha ha, emoji,
Cheers.


Mercedes Vito. Making mechanics out of owners since 1998!?

 

i'm not actually getting a Fault Code for EGR Devito.

However, it's looking like the P1622 Code is s small device/switch/flow through?? that attaches to the high pressure fuel pump. It's tied up to the bulk head at the minute connected to nothing at all.

This is a pic i found on tinterweb. Very rare image this!!!!

 

Already mentioned this in another thread, its supposed to be part of the immobiliser circuit/DAS. Looks like someone removed it instead of fixing the related problem.

It stops fuel going to the rail if it detects wrong key or attempted break in

 

Cheers Andyman, so what can I expect to happen then? Why would it be removed in the first place? I mean it's in a hell of a place the fuel pump.

What symptoms should I have, and will this cause limp mode?


I'm having an Auxillery belt fitted this week so I'll take the pump off and see what needs doing.


The is a project and a half!!!!


I'll probably sell it straight away when I get it sorted

 

Dont think it causes limp mode. Maybe disconnected because immobiliser isnt working and valve was closed constantly, who knows. There are plenty wannabe mechanics in the vito world and bypasses are often found easier than solutions !

 

Ah, right Andyman. Let's see if we can put the immobiliser theory to bed!

OK, so, if the original key I had (assumed to be the one stuck in the barrel) but still using the Transponder in the big plastic thumb, finger, turny bit, was NOT coded for this ECU, then basically, it wouldn't turn over at all?? Would you agree??


I ask this with an assumed certainty, because when i tried to NEW key, the car was actually immobilised. This then suggests to me that the original key is actually, 'The Original Key' as it did not immobilise the van.

 

Yes but the key part is always in the barrel so vehicle always sees a key just not the transponder as it is not attached. This is the way I assume the DAS works, could be wrong though, it has happened once or twice :wink

 

I'm about to have a nervous breakdown here fella's. I really really need to see some progress before I commit a crime!

So, did i mention i had new clocks? Since plugging them in I have ASR, EDC ABS and EMV lights on.

From what limited conflicting info i can gather, ASR is Traction Control? Icon is a yellow tyre far left of instrument panel.
EDC either means Engine Diagnostic Check, Electronic Diesel Control or Every Day Counts!!?
ABS, we all know this one.
EMV something to do with the braking traction control ABS system?????????

The problem is, there is NO ABS pump!! looks like it's been removed.


I think a blind guy and a rabid monkey have been at this van!!!!!

 

Devito. Andyman. Please help me locate p1622 y75. Electric swithover valve.

Could it be electrical contact to high pressure fuel pump. I have not been able to locate a lablelled drawing of the system. P1662 also suggests fuel shut off valve. I have changed it though not attached to fuel supply. No change. However using obd2 no new codes come up if i unplug the new shut off valve. As these are both recorded as p1622 maybe this is why no new codes come up. To reiterate.

P1622 fuel shut off valve
P1622 y75 electric switchover valve. No idea where this is.

 

Left hand side attached to high pressure pump under engine mount (No. 47 in piccy) and just to satisfy that it is the right valve, look at the left of the 2nd pic :wink

 

Cheers again Andyman. I feel like I'm being a bit of a pain now

I know what and where the Fuel Shut off Valve goes and looks like, but i'm tying to assertain IF there is an electric Switchover Valve on the vehicle Y75, that also uses the same error code P1622?


And where can i find out for certain if the removal of this will cause Limp Mode.

I have put a new(used) Fuel Shut off valve on today, but the EDC light comes on immediately when I turn the key after clearing it.

The valve appears to work (electromagnet drives a piston and blocks hole with a small bearing)



We have checked Ohms reading from ECU directly and it's 19! From what I can find it should be 12ohm.


So, Andyman, is the Fuel Shut Off Valve, part Y75?


*****************Sorry, i can see by the pic below that of the pump, clearly this IS Y75!!!. My bad!!

I've either got another bad Y75 or the problem is with the ECU or wiring.

However, I did not attach the valve to the fuel line, only connected it to the wiring harness to give it power. I've assumed this would suffice?

Cheers.

 

No problem, happy to help. I know what a pain they are. Fantastic when they are running right though, best van I've ever driven. Mine out accelerates most cars even with a full load.

This is a guess but if the valve is not connected to the fuel line when the ecu closes it the fuel pressure regulator would still sense rail pressure so this may be the cause of the error. You can be the first to test my theory :grin

Otherwise check the cabling and connectors.

Also, with no valve, how are the fuel pipes connected together ?

 

Hmmmm. interesting. i like your logic.

Looks like I'll need to connect it then.

Now I need to figure out why it was removed in the first place.

I'm assuming it's connected directly to the hp pump, as the car runs.

Car boosts well up to 3000 rpm.

Find me definitive proof that this WILL CAUSE LIMP MODE and i'll buy you a Snickers

 

Find me definitive proof that this WILL CAUSE LIMP MODE and i'll buy you a Snickers

If you connect it and limp mode goes away, surely this is proof :wink

 

Y75 IS this fuel shut off valve.
Get another, new or used, off a sealed clean and dry system, pipe it in where it is supposed to be and plug in the connector.

I've checked my references and Y75 is definitely this valve.
I can't think of any scenario where another component failure would register this fault code.
Eg: Low boost fault code pointing to a failure of the waste gate controller ACTUALLY being caused by a leaking brake booster that bleeds off enough to vacuum not to affect braking (too much) but to prevent the waste gate controller pulling the waste gate shut.
Whew!
Change the valve!


Mercedes Vito. Making mechanics out of owners since 1998!?

 

Copied and posted from my other thread*

WOOOOOOOOHOOOOOOOOOOOOOOOO

Wellllllllll. Boooom! Fixed. Whoooosh.

So, Y75 IS the Fuel Shut Off Valve. It was staring me in the face the whole time. It was screaming at me. Not surprisingly so a it was hanging off the Van by a cable tie and only connected by wiring harness.

What threw me was the description on the OBDII scanner. 'Electric Switchover valve'.


Anyway, it was a help of a job removing and refitting. No easy task.


I haven't driven it today, but fingers crossed all is good.


Devito, this is how the Van was:

Fuel filter to low pressure pump, directly to high pressure pump.
(Shut off valve had power but was rusted in the Closed position. I can only assume because it was rusted in the closed position, this threw the fault.)

However, I changed to a new (used) valve and still Limp Mode. But the small fin inside that keeps the ball central was mssing so the ball would not stay central. called seller and gave me a refund.

Went to Scrap Yard and spent 3 hours removing another used unit.

Spent another 3 hours refitting.

Cleared codes. Still in Limp. Took it for a spin, still no turbo. Cleared codes, turned key, error P1622. cried. Broke down. Cleared codes, took it for a spin, still in LM. Cleared codes, left engine turned off and went in my mates house to cry some more. decided to go home with tail firmly between legs.

Booooom. Whoooosh. Yeeehaaaaaaa. Been celebrating ever since.



So, the set up should be (for anyone else watching) is fuel filter to low pressure pump, to fuel shut off valve to high pressure pump.

As Andyman has suggested, maybe the Rail Pressure sensor pics up pressure after engine off and work back assuming Shut off Valve (Y75) is the problem. OR, it just took a few tries at clearing and a few quick drives, to recycle the ECU and convince itself it was no longer a problem.

Finding out what exaclty was happening would be the ideal scenario as maybe it was working with the 2nd unit I bought, but i just didn't cycle it enough to clear the code.


Right peeps. For all of you that helped. Great stuff. Thanks again.

Next problem is bleeding the clutch AGAIN to see where the issue lies with it sinking to the floor.


Whhheeeewwwww. And Breathe!

 

Good news ?
How you bleedn' the clutch?


Mercedes Vito. Making mechanics out of owners since 1998!?

 

Soooooo...........

When do you want my address for that Snickers :wink

Congrats on the fix, on to the next...

 

First time we did it, we just found the nipple inside the bell housing ans did it that way, but it's back to how it was, so I'm assuming there's ANOTHER way or there's a problem?

Should i start a new thread? It would make it clearer for others!