Heater Booster fault?????

J

jetjockey

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Hi

Just had a friend to check out my 2004 / 2005 W211 (266) E320 CDI again with his Launch unit.

We have a current and stored fault (9470 R22/3) Heater Booster.

Further digging about within the system using the Launch is showing:-

1) Cutoff because under volts Term 30 = Yes
2) PTC Heater Booster Faulty
3) Actual current 255 Amp

Anyone any ideas on this please?

Having never had a Merc before I don't even know if it really is working or not.
I have read that Supply fuses for the Heater Booster burn out but don't know where the Fuse is.

The Fault refused to clear. At the time the battery was down to about 12volt after prolonged testing of the car systems. Could this be the reason?
The BCM was showing no faults and the backup battery was showing 12.6volts. The main Battery was renewed last week and uprated to a Bosch Silver 019 (100Ah and 830 CCA). Way above Merc spec for this car.

I'm scratching my head at the moment? :confused: It's a mystery.

Gerald. :)

P.S. Have not had any "Consumer Services Disabled" warnings since changing the battery last week.
 
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J

jetjockey

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Also, how do I tell if it is actually working?

Is there a simple cast iron test? How Quickly does it heat up and is it a heater element inside the car or is it immersed in the water system close to the heater?

Thanks, Gerald.
 
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J

jetjockey

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Hmmmmmm

Just done much searching on the Forum re this problem.

Many threads proving this to be a real problem area, but no real answers to be found anywhere. Going to nip outside now and start the engine from cold and see if any hot air emanates from the system. Wil also see if I can find the Fuses.

Anybody got any answers? If so please feel free to chip in with suggestions.

Thanks, Gerald.
 
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jetjockey

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Hi MB Service Center.

I Removed and refitted the Audio 20 to fit an Auxillary input for an iPod or somesuch.

Just wanted to check for Can Bus com errors afterwards and clear out the associated fault codes.

During the process we spotted the PTC Heater Booster fault code. Interestingly we had turned off "Auto" mode on the Air Con at the time and were inside my friends Garage where the temp was about 12 degrees.
I wonder if this would throw up a fault code as 2 of the 3 conditions required for the Heater Booster to work were not met?

When going out to the car several hours later the temp outside was down to 5 degrees and I had placed the system back in Auto. Within 20 secs of starting the car, and with the temp selectors inside the car set to 28 degrees, the blower was working and warm air was emanating from the vents. The air was not hot, but it was warm. the engine temp was certainly below 40 deg's as nothing was registering on the eng temp gauge.

Sooooooo......... Is the system working or not I wonder? Unfortunately, never having owned a vehicle with this system before, I am at a loss to know what normal operation is. :confused:

I think I will have to go to the vehicle in the morning and start it from cold. If the air is warm in 20 secs the system must be working. Then the fault code will be a real mystery.

Thanks, Gerald.
 

Alex Crow

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have you tried using the 'rest' function with a cold engine? that will tell you for sure if it is working.
 

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have you tried using the 'rest' function with a cold engine? that will tell you for sure if it is working.

Whats the 'rest' function, is it the one which give heater when engines stopped, ie parked up ?

If i start my 211 220d up from cold and the internal yemp set at sat 22 deg, after about 20 -30 seconds the heater speed climbs to max for a minute or two and warm air comes from vents
Is this the same thing ?
many thanks
 

Alex Crow

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the rest function is used to give climate control when engine is off (obviously no refrigeration). if battery voltage is OK it will use the heater booster when engine is cold.
 

pomm001

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the rest function is used to give climate control when engine is off (obviously no refrigeration). if battery voltage is OK it will use the heater booster when engine is cold.

Thanks
this could explain why the 'booster' is starting to come on only 20-30 seconds after start up , the vehicle has been standing a lot recently, up to a couple of weeks , and i guess that battery voltage is down a bit and after a short lag its up enough to work the booster ?
 
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jetjockey

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Hi Alex.

Ummmm, I didn't think of that. :idea:

I did start the car from cold this morning with the temp selectors set to 28 degrees and the heating in Auto. After a minute there was still no response from the blower. At that point I checked the outside Air temp on the instrument cluster and it said 8.5 degrees. I therefore assumed that the Heater Booster would not work as the temp was above 8 degrees so I abandoned the test.

I will try it again tomorrow morning (Sunday) early to ensure a low temperature.

I have used the "Rest" function a couple of times already and it seems to work very well but that was with a warm engine. I did not realise that the "Rest" function would use the Heater Booster. I thought it could only use the residual heat from the hot engine after a run. There is no mention anywhere in the handbook of this feature working with a cold engine?? :confused:

Thanks, Gerald.
 
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jetjockey

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Well.........OK :)

Right, went out to vehicle this morning. Outside Air temp 5 degrees and engine cold. Climate system in Auto. New Battery on vehicle which had been charging all night so was in tip top condition.

Pressed "Rest" button. Button lit up. Fan started in dashboard area - very quiet - gentle airflow from vents. Whirring sound from under bonnet as Aux Pump started. Noise from dashboard for a few seconds as vents opened.

After 2 mins, air from vents still cold. :rolleyes:

Repeat above excercise with ignition at position 1 and same result. :rolleyes:

It now appears that the PTC Heater Booster is Officially not working. :(
Next step is to find it and start voltage checks etc. I need to see if the problem lies thare or further back in the system.

So.......... Could anybody tell me where in the vehicle this PTC Heater Booster is fitted so that I can take it out or at least test it? Also, where would the fuse be for it please? :confused:

The vehicle is a Dec 2004 (W211 226) E320 CDI Estate.

Thanks in anticipation. Gerald. :)
 

Alex Crow

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hello gerald. just want to say i am glad you are sticking with this forum by the way, lots of banter and cut and thrust, but mostly very good natured.

possibly it is not happy about the battery voltage, although you would expect a 'consumer shut off' warning display if this was the case. i have a niggling feeling that the booster may actually only work when engine is on, as it uses so much current, sorry if i have mislead you!

i understand that on some w211 models the booster is fitted inside the cars climate control housing behind the dash, if you give us the first 11 digits of your chassis number (eg wdb2110262A) we can check.
 
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jetjockey

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Hi Alex

Thanks for that. Point taken. :)

What you say makles sense about the engine running. Just home from the daughters (that cost me) and have tried the system again. This time called up battery voltage display (service) in cluster and showing 13.1 volt.
Pressed the rest button, same story as this morning. Auxilary pump down by driverside headlamp starts up and blower starts on low speed. After two minutes - cold air still.

Just going out to start the engine and try again.

Just wish I knew what to expect. Does the air blower come on at full speed and blow hot. Or is it more of a warm breeze.

Actually, that's just given me another idea. I'm going to start the engine and select "Demist" on the front screen. Back in a minute. :idea:

Cheers, Gerald.
 
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jetjockey

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OK.......... Now totally convinced it's not working.

First of all tried to select the "Rest" function with the engine idling but the system logic will not allow "Rest" selection unless engine stopped. Battery voltage showing 13.8V at idle.

Next try Demist on front screen with engine idling. Blower goes to Max but air stone cold after 1 min so give up on that. :confused:

Keep engine idling with temp selectors set to 28 degrees. Eventually, after 3 minutes, Luke warm (only just) air starts to come from vents. Air certainly not hot and on a sub zero morning would be about as much use as ti*s on a bull.

Stop engine and press Rest button. Lift bonnet and place hand on pipe exiting Auxillary pump. Pipe warm and coolant warm (just).

Obviously luke warm air from vents being caused by luke warm coolant after engine running for 3 to 4 minutes.

So PTC Heater booster defo not working. I now need to get at this thing manually, or at the very least find the fuse or relay to check for a supply or lack thereof. I have a sneaking suspicion that MB may have disconnected this thing without telling my brother (previous owner) because he kept complaining of "Consumer off" warning messages!! :mad:

Can anybody point me to either the fuse or how to access the heater please?
Do I have to remove the Audio 20 etc, or do I go in from under the dash?

BTW Chassis No WDB2112262A............

Thanks, Gerald.
 
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djb

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Hi Alex

Thanks for that. Point taken. :)

What you say makles sense about the engine running. Just home from the daughters (that cost me) and have tried the system again. This time called up battery voltage display (service) in cluster and showing 13.1 volt.
Pressed the rest button, same story as this morning. Auxilary pump down by driverside headlamp starts up and blower starts on low speed. After two minutes - cold air still.

Just going out to start the engine and try again.

Just wish I knew what to expect. Does the air blower come on at full speed and blow hot. Or is it more of a warm breeze.

Actually, that's just given me another idea. I'm going to start the engine and select "Demist" on the front screen. Back in a minute. :idea:

Cheers, Gerald.

on VW s the heat booster only works when the screen defrost is selected and the fan at max, and the engine on, voltage above or around 14v. & cabin temp below a fig I cant remember

I wonder if MB is similar.
 
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jetjockey

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Hi DJB.

Thanks for the info, but with the Front screen Demist selected on, the fan IS at max and the engine was runing and the voltage was at 13.8 volt. Cabin temp was 5 degrees!

This should be working but it's not. My mates Launch X431 confirms it by reporting a current and stored fault (see start of thread).

I can sort this out in 5 mins (Electrically) if only I could find the bl**dy fuse or get at the PTC Heater Booster but nobody sems to be able to tell me exactly where it / they are/ is.

Dohhh!! :confused:

Gerald
 

whitenemesis

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Does this help? 1600W aux heater is #720
 
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Alex Crow

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there you go gerald, it is a complete dash out job just to get near the thing. i will try to find the wiring and connections tomorrow as i know that is your next question ;)
 

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