Calling 2.5TDi Electronauts!

[PAULF]

I have a AFB 2.5 TDi that has had a problem with erratic running. To cut a very long story short, I have traced the fault to the Injection Pump connector plug, I think one of the two wires on the right of the connector is the culprit. A bit of movement on either of these wires brings up the fault. Does anybody know how the connector splits, in order that I can check the crimp connection to the wire? I have removed the clamp to access the individual wires, but I am not familiar with this type of connector.
VCDS gives fault codes 0546 and 01318, which point to IP comms/wiring.
A basic Internet trawl has not given me many clues - most just point to the pump replacement, not the harness plug.
I have obviously already cleaned the connectors and tied the loom better, which seemed to have helped for a while. The fault reappeared today, so I have just 'adjusted' the two suspect sockets' clamping force, which cleared it again - and I 'wiggle' tested it quite vigorously!
The wife still is worried that it may fail again, so I want to remove the socket from the connector and check it physically.

 

[rossbrownlee]

Think pin 1 and 4 (green/yellow and brown wires) are your supply to the pump, 2 and 4 are your level sender signal pair.
Normally on VAG connectors you will find that there is a locking tab which is normally pinky purple colour. this has to be pressed one way or other until it clicks into the unlocked position. Once that is done you need to insert a tool in at the side of the crimped parts from the opposite side of the connector to where the wire insulation is, i.e. the part that faces the pump, the crimped connections have a pair of barbs that click into place as you insert the crimp connector into the plastic housing preventing it being pulled out. This is a special tool but i successfully used cut up slivers of coke bottle before and that worked fine.
Check out on youtube there are videos of VAG connectors being disassembled.

 

[aragorn]

Ross: He means the injector pump on the engine, not the in-tank fuel pump!

 

[rossbrownlee]

 

[PAULF]

Thanks for trying, Ross,
I suspected that there would be some form of extract tool, and I expect the injection pump connector will be similar to the connector you describe. I have access to plastic extractors, so if nobody gives me better info, I'll try that if the fault returns.

 

[PAULF]

******,

That's 0546 back after a week clear, so I guess I'll have to try and de-pin the connector and check the pin connection as the next step.

Of course it could always be the PCB connection in the pump................

 

[PAULF]

Thought I'd post an update on progress so far.....
After much internet searching, it appeared that the fault would be the internal pump connections as opposed to the connector, so I sent the pump off to Diesel Bob, along with all 6 injectors. There were other 'pump/injector duff' symptoms, such as a little bit smokey, MPG's a little down, and a 'Bark' that suggested it was advanced too far even though VCDS showed it bang on.
Bob fixed all the duff bits, all accolades already posted are seconded for a good job well done, but he could not fault the ECU!
I now am back looking to de-pin the pump plug, to see if my original fault diagnosis stands
I'll most likely try so splice in another second hand unit as I don't want to destroy the one on the car.

Almost all info on these pumps failing refers to the ECU, so it may be worth noting the connector does fail sometimes. Also Diesel Bob found that my ECU was essentially fine, but the mechanicals of the pump needed adjusting - something most pump fixers don't do!

Edited to add:
BTW, if anybody has a pump connector plug with a couple of inches of wires on it going spare please let me know!

 

[PAULF]

To give a last info update,
The pins are crimped to the wires, and slot into a metal lock cup in the plug. It would appear they come out from the rear, but it was not easy. The pin locks also came out through the rear. I used standard extract tools to remove the pins, but a refit would have been difficult due to the rubber seals around the top.
In the end I cheated and spliced in another plug from the scrappy - problem solved!

 

[PAULF]

An update........

In the end I cheated and spliced in another plug from the scrappy - problem solved!

.....Or problem NOT solved! During the September service, the code was back. There has been no visible indication via smoke or jerking. I fiddled a bit more with the plug, and then gave up. It did not effect the car, so I thought I'd wait until things got worse and I had some visible effect to chase down the cause of.
The code would come back randomly after clearing.

I have also been having DIS grief (DIS dead) and eventually changed the dash insert for another unit.

There has been no 0546 code repeat since the new unit has been fitted. It really does look like I've been a bit unlucky, and suspect it unlikely anybody else will have the same trail of events, but it seems the loose pins did cause the erratic running, but not the 0546 loss of data code.

Ho Hum, at least she now has a known good pump and injectors to go with the Vege engine and turbo