vito 113 battery drain - fuse 12?

[bretiller01]

Hi All, new here and hoping someone can help

Bought a 2.0 petrol vito 113, eventually it'll be my excellent surf van, been battling with loads of problems, asr,fueling, ROT! you name it! etc etc but the latest one has got me stumped

It has a parasitc battery drain through fuse 12 - heater control, average of 1 amp, killing the battery in 1/2days. the system seems to stay awake. With the van off, key out, doors shut - i can still turn the temp control up and down and hear the DUO VALVE working, its an electrical setup not cable and it is not the little electric pump i can hear, its definatly the duo valve. I can't hear any fans spinning, Could this be a stuck relay? providing a constant feed?
if i pull the fuse the drain drops significantly- but then the side lights dont flash when i lock it? fuse back in and lights flash.
I checked the codes and got nothing back, i even created a few and pulled 1 or 2 sensors to make sure my reader was working.

Van seems low on power aswell

Any ideas?

 

[bretiller01]

Extra info,, the A/C pump also failed miserably, smoke and burning smell.. so money being a little tight i decided to bypass the pump completely with a new belt untill i can source a new pump, Its got me wondering if the connection's to the pump are fubar, or the REST and A/C button might be faulty as the rest button can be used to heat the cab after the key is removed, i think.
wondering if the vito route was not one of my best idea's.

 

[BTB 500]

wondering if the vito route was not one of my best idea's.

Hi & welcome to the Forum. I assume is this an 'old shape' (front wheel drive) 638 Vito? Unfortunately these were not exactly Mercedes' finest hour and - as you have found out - can suffer from a wide range of issues, including electrical gremlins.

What else is on fuse 12, according to the handbook? Does the van have an alarm?

 

[bretiller01]

Cheers Bud, Yep its 2001 638 2.0l petrol
according to the manual its the heater control unit, there are only 2 other fuses/consumers just below it in this stack,
FUSE 11- rear window relay, ANTI THEFT SYSTEM/C-locking - which all seem to work with fuse 12 out, with the exception of the flashing lights when i lock it,, alarm/c locking? hmm
FUSE 10- trailer socket

And above is FUSE 16 - operating device for heating

but the drain only drops when i pull fuse 12,
I'm pretty useful, so far i defeated the ASR and ABS gremlins, a MAF Troll, a knome hiding in a ceased caliper and an evap purge fairy err fault.. what next!
this vans got me demoralised. other than this it runs ok albeit i suspect a duff temp sensor and oxy sensor sucking a bit of power

feel a visit to an auto electrician coming on, better ready the credit card

 

[Danny DeVito]

Temp controls should certainly be of when key is out. Only the rest button should work. Have you tried unplugging the heater control unit from the back ?

Also what was ur asr fault ? ( i have one )

 

[Danny DeVito]

where is fuse 12 found ? under the paso seat middle row third one up ? Do you know ur engine model ?

 

[bretiller01]

RE danni devito

ASR + ABS Fault
Problem - all the ASR/ABS lights were up but van drove alright- but crap brakes
checked all ABS sensors on calipers (wheel speed sensors) Turn your steering wheel full left or right, the sensor is fitted to the top rear of each calipers
found the front passenger had been CUT! WHY? read on!! I repaired it,,
BANG!!!! ASR and ABS now working properly couldn't get over 30mph! WOW! is asr intrusive,, its like an anchor was thrown out the window.
NEXT- checked tyre sizes - the front and rears were different sizes approx 4to5% difference

The previous owner thought it would be cool to have bigger rear tyres, but the ECU figured all wheels were turning at different speeds and kept cutting in with ASR, to fool the ECU he cut one of the ABS sensors. this had the effect of throwing up appropriate lights and reducing braking power

My advice would be
1) check tyres sizes and pressures to start, even a small difference in size is enough to trigger asr,, all the numbers on tyres and the pressures need to be the same
2) check all 4 abs sensors and give them all a good clean, also each sensor sits just above the toothed ring on the shaft ( i forget the correct term) give that a clean also, the whole assembly is very exposed under there and can get pretty mucky and damaged
3) have a look for broken damaged or loose wires to and from the sensor,, not only was the my sensor cut,, but the wires were also shorting at the base on sensor. Replace as neccessary
4) if the above doesn't help, check your fuses

hopefully it's a simple fix mr devito, get back to me if this helps


AS for my vito,, fuse 12 under the passenger seat,, middle column of the box, i've put it into an auto electricians today for a full electrical work up,, the BAT drain and the crap mpg

 

[Danny DeVito]

Any update ?

I already cleaned the sensors etc. the tyres are the same. No faults are logged for abs, no warning lights are up. So i assume the car thinks one of the wheels is spinning. I think either the abs sensors are giving bad reading or maybe the diff is causing a problem due to drive shaft popping out, or maybe the play in the drive shafts ? Asr chucks my anchor out as soon as i gor around bends over 60pkh. Also while changing lanes gently on the motorway. I usually just turn it of

 

[bretiller01]

SOLVED, maybe !
Turned out to be the instrument cluster, it was affecting all other systems. I have no idea how though.
Took it out and sent it to autotek uk for repair, since its been out my battery is alive and kickin after 4 days, normally dead after 24 hrs ish. Fingers crossed. I will get a report from auto tek UK describing exactly the fault and I will post it.

Danny, difficult to see how the drive shafts would create an asr prob. Ecu gettin wrong info on wheel speed, so quite likely to be bad sensor or loose connection if all tyres are the same size and pressures. Any codes Being thrown up? i use a clarke obd11 reader - bout 35 Quid from machine mart, and it works great! So long If your vehicle is obd11.
Turning or jolts from cats eyes kick asr in? Loose connection or short? Are all the tyres the same age? if some tyres are old or worn and others new, there might be enough size difference from New tyre to a worn tyre to trigger asr when you get up to higher speeds.

 

[Danny DeVito]

Actually the tyres front tyres have about six months in age difference. I wonder if the tyres may physically be different sizes from new because they are quite a cheap tyre and different brands. Maybe next time i wil try get two the same at the same time. I dont think its jolts because it can happen just turning gently. When i have it turned of the warning light is on and flashes to tell you its reading problems. It flashes away as soon as i begin to move right or left

 

[bretiller01]

Could be that simple, that small difference in size at higher speed may be noticed by ecu as different wheel speeds.

 

[spewen]

Fuse 12 power drain...

Hi Bretiller,

Did you ever get to the bottom of the 'fuse 12' power drain???

Sounds very familiar, I ran my van for around 12 mths with no fuse in as the battery was running flat over night, winter was fine, summer was a little hot!

I've recently replace the duo valve but a few days later I was replacing the front brakes and noticed the dreaded clicking duo valve closely followed by dead battery...:fail

Any help would be much appreciated

 

[Benvito]

Hi All, new here and hoping someone can help

Bought a 2.0 petrol vito 113, eventually it'll be my excellent surf van, been battling with loads of problems, asr,fueling, ROT! you name it! etc etc but the latest one has got me stumped

It has a parasitc battery drain through fuse 12 - heater control, average of 1 amp, killing the battery in 1/2days. the system seems to stay awake. With the van off, key out, doors shut - i can still turn the temp control up and down and hear the DUO VALVE working, its an electrical setup not cable and it is not the little electric pump i can hear, its definatly the duo valve. I can't hear any fans spinning, Could this be a stuck relay? providing a constant feed?
if i pull the fuse the drain drops significantly- but then the side lights dont flash when i lock it? fuse back in and lights flash.
I checked the codes and got nothing back, i even created a few and pulled 1 or 2 sensors to make sure my reader was working.

Van seems low on power aswell

Any ideas?

Hi mate,
Im going through the exact same problem with my 2002 vito 112 (638)
Narrowed it down to fuse 12.
I have a parasitic drain of nearly 1A.
When the car is turned off there is still power to the solenoid valve that controls the heating (under bonnet behind the airbox)
The solenoid is operating correctly when the car is running. But the only way you can de-energise it is by pulling the fuse/ cycling the power.
Im at the point of installing a toggle switch into the circuit for a quick fix.

My question is did you find the cause of why the solenoid is staying on causing the drain?
Im guessing now there may be a something latching electronically inside the heater control unit in the centre console.
Im about to source another one and try replace it.
Cheers.