Year of Manufacture *: any Engine Size and Code *: Any diesel (Mine was a 2.0 single turbo however) ( Optional ) Scanner Used: VAG-COM ( Optional) Fault Codes: See main text
Symptoms are;
Intermittent MIL on, severe power loss.
On scanning for faults codes;
11901/P0236 Manifold pressure implausible. 4124/P0651 Sensor reference voltage B open circuit 4881/P1440 EGR valve open circuit 5242/P0191 Fuel pressure sensor implausible
were present.
(Some reports have a different set of codes faulting different components but what they all have in common a 5v sensor supply rail)
The test is to clear the codes, disconnect the EGR electrical connector and take for a test drive. It should drive fine and only EGR faults should return.
(It is also possible to carefully remove the plastic cover on the top of the EGR assembly and look, it will be full of condensation and corrosion)
On the single turbo it is actually relatively easy to replace. the assembly is held to the side of the cylinder head with 4 Torx bolts, three are accessable using standard tools but you will need to use a torx "L" key with a deep socket to provide extra grip to undo the lower RHS one because the EGR pipe is in the way.
You will also need a 10mm spline tool to undo the lower EGR pipe retaining bolts, all the other bolts are Torx ones and easily acessable.
All you need to do is undo the water pipes (Remove the short RHS one completely for better access)
Undo the upper and lower EGR pipes also on the RHS
Undo the four retaining bolts holding the assembly to the cylinder head and remove.
The replacement unit comes C/W the EGR cooler and is quite expensive, you will also need the two new gaskets for the EGR pipes.
As in the immortal words of the "Haynes Book of Lies"
Reassembly is the reverse of disassembly!
(I understand however that the equivalent repair on the bi-turbo engines is considerably more difficult and time consuming )
If I can figure out how to post a picture I will provide one showing what goes on inside the (badly designed!) egr valve )