Flashing Glowplug light, lack of power, now dead 2.0TDi 150

Davegsm82

Veteran Member
Joined
Oct 6, 2010
Location
Newcastle, UK
TDI
MK7 Golf TDI 2.0 CRB 150BHP + T25 Vanagon AFN 110BHP
Driving to work this morning I got a flashing GP lamp and lack of power, what felt like a misfire (more like a rev-limiter) above 2500rpm.

At the same time and Error popped up on the MFD saying Start-Stop system error. Probably unrelated but I did notice that it happened immediately after the SS became available, about 7 miles away from home, because the status screen was up on the infotainment unit.

Fault persisted after turning the engine off/on.

managed to get VCDS plugged in and the codes are pointing to fuel pump issues, before clearing codes and trying to start again I had;

5211 P0087 - fuel rail system pressure - too low
5212 P0087 - fuel rail system pressure - too low
5231 P0087 - fuel rail system pressure - too low
10058 P3045 - Fuel pump - electronics defective
10062 P3044 - Fuel pump - short circuit.

After clearing, still have the last 2 codes relating to fuel pump and the engine will still not start, it occasionally splutters and tries to fire but fails every time.

I Have checked the HP fuel pump (CP4) on the front of the engine and the filter, I expected to see metal shards if the pump had failed but all I could see were 2x tiny little flecks of silver, barely a hairs width and maybe 1mm long on top of the filter. Absolutely nothing at all inside of the N290 valve housing on the pump, completely clean inside and the strainer on the valve is also clean. Fuel filter was also full to the brim.

In VCDS, using the measurement units the ID for "High Fuel pressure: control deviation" shows 290100 hPa at ignition on, during cranking this sometimes gets up to about 350000~, but when you look at the ID for "Fuel pressure valve: desired pressure" (possibly not the exact description but close enough) it shows exactly 850000 hPa.

Obviously from this it looks like the HPFP isn't building enough pressure. Whether this is because of failure or restriction down the line I'm not sure.

The only other thing I've tried is to check the connector and what wire I could see on the HPFP top front of the engine, and also ran output test in the engine control unit on the LPFP (lift pump) in the fuel tank, which I could hear chuntering away - not a continuous noise but more like clicking from under the back seat, more audible from outside of the vehicle. Does anyone know if this is normal?

Any advice on this is welcomed as I am at work until 6.30pm and I have normal socket sets, hand tools, multimeter etc available so can try various things.
 

thundershorts

Top Post Dawg
Joined
Jul 15, 2010
Location
west chester pa
TDI
2015 passat tdi sel premium 2015 golf s tdi gls tdi b5.5, 2002 eurovan,Peugeot 505 td,Citroen cx25 prestige
The low pressure codes you have sound very much like the lift pump is or has failed. You may find the replacement pump has superceded part number. The lift pump itself will generate no codes at all. It should not be noisy, just a very low hum.
 

Davegsm82

Veteran Member
Joined
Oct 6, 2010
Location
Newcastle, UK
TDI
MK7 Golf TDI 2.0 CRB 150BHP + T25 Vanagon AFN 110BHP
Turns out it was the Fuel pump controller, although I have replaced both it and the pump/sender unit with items from a scrap car.

Original controller part number was 5Q0 906 121G, replaced with a 5Q0 906 121P. Simple plug and play replacement.

I did a LOT of analysis of the controller, pump etc using my oscilloscope and multimeter, took some photo's and video to show to others what to look for in the future. I'll compile the details into a how-to type thing, is it worth posting in here or a new thread?
 

Davegsm82

Veteran Member
Joined
Oct 6, 2010
Location
Newcastle, UK
TDI
MK7 Golf TDI 2.0 CRB 150BHP + T25 Vanagon AFN 110BHP
Writeup of this over on the MK7 forum;

 

thundershorts

Top Post Dawg
Joined
Jul 15, 2010
Location
west chester pa
TDI
2015 passat tdi sel premium 2015 golf s tdi gls tdi b5.5, 2002 eurovan,Peugeot 505 td,Citroen cx25 prestige
The tiny shard you saw in the filter was most likely from the lift pump. If it happens again, you may have to sport for the newer lift pump.
 

thundershorts

Top Post Dawg
Joined
Jul 15, 2010
Location
west chester pa
TDI
2015 passat tdi sel premium 2015 golf s tdi gls tdi b5.5, 2002 eurovan,Peugeot 505 td,Citroen cx25 prestige
Was the used lift pump you used from a diesel or gasser?
 

Davegsm82

Veteran Member
Joined
Oct 6, 2010
Location
Newcastle, UK
TDI
MK7 Golf TDI 2.0 CRB 150BHP + T25 Vanagon AFN 110BHP
Was the used lift pump you used from a diesel or gasser?
Lift pump and control module were from a diesel, same as mine. The Gas/petrol versions are different, I think they use a conventional style pump as the controller unit only has 5 wires, instead of the 6 on this one.
 
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