# EGR coolant pump intermitent fault.



## Gabs08PHTN (Jan 6, 2011)

Hi all,
I run a VCDS scan this morning and came with the following intermitent fault: 

_ Address 01: Engine Labels: 
Control Module Part Number: 3D0 907 401 D HW: 3D0 907 401 D
Component and/or Version: 3.0TDI EDC17G100AG 0070
Software Coding: 0406002C190F0160
Work Shop Code: WSC 01065 000 00000
VCID: 20459124F0D8FCE
1 Fault Found:

005276 - EGR Coolant Pump 
P149C - 000 - Open Circuit - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 2
Fault Frequency: 7
Mileage: 116169 km
Time Indication: 0
Date: 2014.11.01
Time: 17:19:24

Freeze Frame:
RPM: 1176 /min
Speed: 7.8 km/h
Temperature: 171.1°C
(no units): 56.0
Temperature: 66.6°C


Readiness: 0 0 0 0 0 _

I checked the connector at the EGR coolant pump side and it looked fine. I will keep an eye on the fault just in case it starts appearing often.
By the way, yesterday I drove for about 300km in the morning at about 140km/h. The fault came on shortly after firing the engine for the return trip.

Gabriel


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## Paximus (Aug 26, 2011)

Just to inform the discussion (and confuse myself, because I don't see an EGR Coolant Pump explicitly shown) here is the SSP diagram of the 3.0TDI cooling system.

Chris



*TDI Cooling Circuits*









image (c) volkswagen


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## Gabs08PHTN (Jan 6, 2011)

Paximus said:


> Just to inform the discussion (and confuse myself, because I don't see an EGR Coolant Pump explicitly shown) here is the SSP diagram of the 3.0TDI cooling system.


Hi Chris,
Yeap, it does not show up on that diagram. 
The reason is because that is the BMK (225HP) engine cooling diagram and it does not fully represent the CARA (233HP) engine. If you search for SSP 840193, you will notice that although it is the "Clean Diesel" SSP, it shows up an EGR cooling pump like the CARA engine does. 
In that respect, it also seems to me that the CATA engine quoted on that SSP was developed from the CARA and CARB engines baseline.

Gabriel


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## Gabs08PHTN (Jan 6, 2011)

Following the previous post, I report that the anoying EGR cooling pump intermitent fault is reocurring. Hence, it all points out that I will have to replace it shortly.
Any other ideas you bunch of clever heads? 

Gabriel


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## Paximus (Aug 26, 2011)

Hi Gabriel,

Thanks for that drawing clarification.

I cannot think of any other 'open circuit' report on the diagnostics that doesn't tell the truth. Presumably the method of reading the voltage across a series feed resistor is very reliable.

In that case, if it is not a wiring loom or plug contact, it must surely be oil contamination on the pump motor armature, or worn brushes.

Chris


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## Gabs08PHTN (Jan 6, 2011)

Hi all,
The day before yesterday when returning home from work the Check Engine light came on. At home I scanned the Phaeton and came across this fault:

_005276 - EGR Coolant Pump 
P149C - 000 - Open Circuit - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100000
Fault Priority: 2
Fault Frequency: 1
Mileage: 117307 km
Time Indication: 0
Date: 2014.11.20
Time: 15:55:16

Freeze Frame:
RPM: 798 /min
Speed: 0.0 km/h
Temperature: 70.8°C
(no units): 60.0
Temperature: 59.4°C


Readiness: 1 1 0 0 0 _

As it seemed that the pump had finally given up, I ordered a replacement from my local VW dealer. It should arrive on Monday, so as soon as I replace it, I will report back.

Gabriel


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## Gabs08PHTN (Jan 6, 2011)

I have just removed the faulty pump.
It is not a difficult task. It is bolted onto the front engine lifting eye by means of three smal torx bolts. Other than the bolts, a plug has to be disconnected from the pump and another single wire one from below the pump, in order not to soak it with coolant.
I also had to undo two hose crimping clips that seal the hoses than run from the thermostat to the pump and from the pump to the EGR cooler. After that it is a matter of some persuasion to remove the hoses from the actual pump. In addition to that, I plugged the hoses with two red wine bottle corks  until the new pump arrives.
After the pump was removed I disassembled it, but could not find anything wrong, unless there is a faulty component in the electronic board that controls the motor that cannot be spoted by the naked eye. 
It is a quite neat design as the pump features a wet and a dry side. In the wet side there is the impeller that includes a circular permanent magnet alongside its perimeter. It is driven by four switching coils located on the dry side. These coils are controlled by a small circuit board also located on the dry side.
Now I have to wait till the new pump arrives and lightens my wallet by 142 euro.

Gabriel


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## Gabs08PHTN (Jan 6, 2011)

I have just installed the new EGR cooling pump and went for a test drive. So far so good! 
The new pump part number is 059 121 012A, whereas the old one was 059 121 004F. Therefore, I would say that there must have been some sort of design change, although externally they are alike.
As I indicated in the previous post, the pump is bolted onto an engine lifting eye. What I noticed after fitting the pump and firing the engine is that it has to withstand quite noticeable vibrations as it oscillates together with the engine. I am speculating, but perhaps, that was the most likely cause of its failure.

Gabriel


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## Paximus (Aug 26, 2011)

Hi Gabriel,

Glad you got to the bottom of the problem! 

For thread reference purposes, in case others arrive here later looking for solutions (and seeing the complexity VAG have now achieved I would not be surprised!), I have copied below some drawings relating to EGR cooling from the SSP you quoted.

Chris



*EGR Coolant Pump*









image (c) volkswagen

"Exhaust Gas Recirculation Cooler Pump V400 activates after engine start and supplies the EGR with cold water directly from the radiator [output]. The coolant regulator for the EGR controls the temperature in the EGR at a constant 131F (55C) independently from the outside temperature. The additional EGR cooler is connected in series to the main cooler. This additional EGR cooler is integrated into the engine cooling system circuit which is controlled at a temperature of 188F (87C)."


*Here is the revised Coolant Circuit for the latest VAG low-emission V6 TDI engine*
(it looks to me a bit like the circulation in a Budweiser factory! But don't drink coolant...)









image (c) volkswagen


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