Testing and Diagnosing the E53 Webasto Thermo Top C/Z

jaynana · Post by **jaynana** » Mon Oct 08, 2012 9:16 pm

Thanks CondorX5, i've sent him a pm.

Wilcoturbo, i've pmed you.

cheers

j

wilkoturbo · Post by **wilkoturbo** » Wed Oct 10, 2012 10:18 am

Is this the same ??
160401073150

wilkoturbo · Post by **wilkoturbo** » Mon Oct 22, 2012 7:42 am

[quote="wilkoturbo"]
Right I have wired power to pin 1 via a remote it powers up for like a minuite then shuts off , I've read the fault codes what next :(

[/quote]

jaynana · Post by **jaynana** » Mon Oct 22, 2012 11:25 pm

[quote="wilkoturbo"]
[quote="wilkoturbo"]
Right I have wired power to pin 1 via a remote it powers up for like a minuite then shuts off , I've read the fault codes what next :(

[/quote]
[/quote]

what's the sw you're testing with? the screens don't look familer. in any case this is the car's diagnostic similar to what i read with the scanner 1.4.0.

webo is reporting an error. possibly with the glow plug.

when you say it powers up for like a minute and then shuts down, a few clarifications:
1. does it power up even with this error present or does it power up when this fault is cleared?
2. when it powers up do you get hot air from the webo silencer under the passenger side door? or do you get cold air only?

i'm trying to figure if the glow-plug is faulty.

based on above, but the next question would be - can you measure the glow-plug resistance and let me know. you have to remove the top cover of the webo plugs, remove the glow plug connector to measure the resistance:

glow plug is the blue/white connector in the above photo (you only have to snap out centre plastic cover which covers the connectors, don't have to expose the pcb as in the photo. you don't have to remove the webo unit to do this, you may have to loosen it though.. its held in place by 4 screws that needs to be loosened)

all the best

j

cheers
j

jevansio · Post by **jevansio** » Wed Oct 24, 2012 1:16 pm

Sorry if I'm hijacking but thought I'd keep this with all the other webasto stuff

I've done the 12v to pin 1 test for 30 sec + and am getting nothing. Fuse 59 is fine and I've checked major 12v in with voltmeter. Glow pin is showing resistance of 1.1ohm (which is way off the recommended 0.3 to 0.6).

Which way forward would anyone advise?

Do I buy the diagnostic stuff to see what the webo says
Do I just buy a 2nd hand working unit and diagnose mine in slow time off the vehicle
Do I buy a new burner unit and hope the Glow Pin is really the issue
Or are there any simpler checks I should be performing 1st

I've done the 30 sec fuse 59 out thing, and also done the reset defined in the webasto manual (3 sec fuse out, turn webo on, 3 sec fuse out again).

Any tips welcome as I'm on the verge of just buying a 2nd hand unit

Jay

jaynana · Post by **jaynana** » Wed Oct 24, 2012 9:13 pm

A lot of ppl have asked various questions about what to do if webo doesn't work on +12v to pin 1, plus i'm trying to help a few ppl on email directly as well.

so i thought of a general guide..

pre-requisites when you do the power to pin 1:
1. i think you need to have aux heating enabled with a scanner or similar on the obc (not sure if webo works without being enabled in the obc)
2. good battery voltage (i think webo is designed to not run way before car becomes unable to start due to low voltage)
3. coolant temp has to be be below 60c (so if the car has already run, nothing much extra the webo can do, so it won't start)
4. no errors logged in the aux heating module of the obc

if the webo doesn't work on +12v to pin 1, here are the options i can think of:

1. you can easily get a used webo from a breaker with warranty from fleabay..
- pros: easy, webo is like plug and play
- cons: only hope the issue is not external to teh webo. important external components are the water pump and the fuel pump
2. get a diagnostic kit (Reslers along with webo test sw is my choice)
- pros: you can individually test the water pump, air fan, fuel pump, full working unit, read and clear the webo fault memory, etc
- cons: assume you find an error. so what next? this is a long journey.
3. test and repair/replace the pcb and/or the glow plug. This is the Achilles' heel on the webo. my proven source is this.
- pros: you can run the car with these components removed. at a relatively low cost you can certify the most suspicious part
- cons: not as easy as plug and play. have to dismantle the webo to remove the glow plug.
4. service the webo. instructions at teh start of this thread. glow plug failure is usually caused by muck. webo is like your boiler in teh house, except, it has never been serviced!
5. go the whole 9 yards.. like i have!

webo is a beast, not easy to diagnose! i had this exact same situation when i started (webo initially worked for about a minute, but only blew cold air from teh silencer, eventually it stopped working even when i clear the error on the obc - possibly got into a locked out state).

i spent considerable time and money to get this sorted. having done that, i can recommend the above approaches to anyone so that hopefully you can avoid.. at least a part of the nightmare

all the best

j

jevansio · Post by **jevansio** » Thu Oct 25, 2012 8:18 am

Excellent info, will post my results whatever path I take

jevansio · Post by **jevansio** » Sat Oct 27, 2012 7:20 pm

I have made some progress:

The unit has eventually sprung into life (after performing one of many reset procedures I have read during my travels) - I always suspected the fact it appeared totally dead was down to the lockout

Pin 1 now causes the air fan to whir. I checked the 12v out to the water pump and that is running (I can feel it vibrate with my hand too).

Next I forced a 12v to the dose pump, it clicked like a relay then nothing. I pulled the fuel pipe off and tried again and nothing comes out the pipe. I went under the car pulled off the cover and checked the pump was getting 12v, it was. So now I'm thinking my dosing pump is goosed. Anyone else had a pump failure?

Trying to find a replacement for a decent price is proving trickier, there are a couple of generic webasto dose pumps for thermotops on ebay for around £60, anyone know if the connector/housing is the same as the bmw? I'm tempted to try as at the end of the day it's just a 12v pump and I'm sure I could get it mounted/wired to the car somehow :/

PS I don't have aux heating enabled yet (although scanner 1.4.0 is on it's way from China) so it's not essential if you are at the fault finding on the webo stage

X5Sport · Post by **X5Sport** » Sat Oct 27, 2012 7:32 pm

Glad you are making progress. I didn't have 'Aux Heating' enabled on mine either, and can confirm that 12V on Pin 1 with a cold engine brought the system into life. Mine was fully working so fired up and ran with no issues.

jaynana · Post by **jaynana** » Sun Oct 28, 2012 1:29 am

good to see progress

[quote="jevansio"]
Next I forced a 12v to the dose pump, it clicked like a relay then nothing. I pulled the fuel pipe off and tried again and nothing comes out the pipe. I went under the car pulled off the cover and checked the pump was getting 12v, it was. So now I'm thinking my dosing pump is goosed. Anyone else had a pump failure?

[/quote]

i haven't directly powered up the fuel pump with 12v. my fuel pump didn't work as i thought either - it didn't pass the test even when switched on with the webasto test software.

i also almost replaced the fuel pump, but then because the sw was also reporting a glow plug fault i took a chance and focused on the pcb and glow plug, which eventually paid off.

so it turned out that there was nothing wrong with the fuel pump.

i haven't removed the fuel pump but like most components on these cars if it has a k-bus interface it probably wouldn't run on just getting power; it would wait for a command. On the other hand if it just has a power input it certainly should run when its given power... how many wires has it got going into the pump?

j

jevansio · Post by **jevansio** » Sun Oct 28, 2012 7:56 am

The fuel pump has 2 wires J,

Yeah I'd read your fuel pump red herring and it's the only thing leaving me feeling a little unsure ATM

I wish I had just taken it off yesterday while I was under there now so I could do more bench tests

I'm hoping my hunch is correct as the 6 pin webo plug has 2 other wires going out, 1 in the diag plug which I'm hoping is the kbus, and this thicker one in the dosing pump pin which I'm hoping the thicker wire is an indication it's carrying more current to drive the pump rather than just being a signal wire

BTW, is there a common workshop cd you guys use on do you just use what seems a quite good free info source from places like spaghetticoder?

jaynana · Post by **jaynana** » Sun Oct 28, 2012 9:09 am

[quote="jevansio"]
The fuel pump has 2 wires J,

[/quote]

i see.. it just might be ground and +switched power supply then.. only hope its not power and k-busand the unit is grounded

[quote="jevansio"]
BTW, is there a common workshop cd you guys use on do you just use what seems a quite good free info source from places like spaghetticoder?
[/quote]

CD? you wish.. naah all information from helpful ppl and scavenged from various websites. said that, pm me your email and i'll send you the bmw webo service manual. that might help

cheers

j

jevansio · Post by **jevansio** » Mon Oct 29, 2012 6:41 am

That'd be great J, pm on it's way

PS that webasto of yours went for a song, I was going to bid on it until I started suspecting it was the pump and would have payed a damn site more than that

jaynana · Post by **jaynana** » Mon Oct 29, 2012 10:33 am

[quote="jevansio"]
That'd be great J, pm on it's way
[/quote]

emailed 2 guides, one was particularly helpful to me.

[quote="jevansio"]
PS that webasto of yours went for a song,
[/quote]

yes! blo0dy webo and my impatience!! it only costed £90 to get my webo fixed, wasted another £90 in buying and selling that used blo0dy webo!!

thing is i didn't know of the webo pcb repair guy in germany at that time, i had sent him an email he hadn't replied, plus i didn't know if he was reliable.. so there were much less options at my disposal..

jevansio · Post by **jevansio** » Mon Oct 29, 2012 7:18 pm

Massive thanks for the pdf guides J

More progress too. Was telling my mate & he said the dosing pump will be delivering 1 "dose" everytime its activated, hence the solenoid type thunk. So I applied and remove the 12v a number of times and hey presto fuel is coming out the end of the pipe

Just got to wait for the coolant to cool off again before I can try the 12v pin 1 test, and if it don't work this time there's no option but to remove the unit and clean the burner. Will keep yall informed

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