VW / Audi / Seat / Skoda (VAG) Bosch EDC17CP04 Engine ECU Repairs

Type: Bosch
Fits: VAG – Audi / Seat / Skoda / Volkswagen (VW)
Fuel: Diesel
Ref: ECUT337325

Note: This ECU may also fit other models.

The Bosch EDC17CP04 is the engine control unit on Audi’s 3.0 TDI V6, and most of the published record on it was written by people changing what is stored inside it rather than by people repairing it. A unit that has failed on its own is a different problem, and that record does not answer it. This page sets out what is documented as failing on this ECU, and what to do when one has. It is a diesel engine ECU, and putting one through a full test and rebuild is what happens to it here.

What the published record on this ECU is mostly about

Search on EDC17CP04 and almost everything that comes back concerns the software inside the unit rather than the unit itself. That body of knowledge is large and accurate about the question it answers. It is not the question an owner or a garage is asking when a car of this family has stopped.

The same is true of the failures themselves. Where a dead EDC17CP04 is written about at all, it is usually one that had just been written to and stopped working immediately afterwards. Those faults were caused, at a known moment, by a known action.

Faults that were caused, and faults that occurred

A unit that stopped working seconds after new software went into it, and one that stopped on a car nobody had touched, are not the same fault. The first has sound hardware and altered contents. The second usually has intact contents and hardware that has failed, so the recovery methods built for the first have nothing to act on.

That is why the sheer volume of material on this ECU helps so little when a unit has simply stopped: none of it is wrong, it is aimed elsewhere. Remapping, tuning, cloning and immobiliser work are not services we offer. What we do is repair the hardware.

What Bosch documents as failing on this unit

Bosch publishes an error-pattern list against 0281014725, which is the single part number carried on this page. It names an exhaust control valve that stops working, exhaust gas recirculation that is no longer actuated, various error codes, P0603 recorded as an internal control-unit fault, a connector that is oxidised and damaged by water, and no communication with the ECU at all, with fault-code reading no longer possible.

A separate published list for a sibling EDC17CP04 used on the Q7 adds misfires on individual cylinders, P0603 again, P1387 with the car failing to start, and injector problems under P1592.

Water is named directly in the manufacturer’s own list, in the words oxidised and damaged by water. That makes moisture reaching this unit a documented cause of its failure rather than an inference drawn from a few examples. Where moisture has reached it, the way in has to be dealt with as well as the unit.

A fault set that does not look like one part

Read the two lists together and their spread is the useful thing about them. One runs from an exhaust flap that stops working, through exhaust gas recirculation that is no longer actuated, through a code recorded against the control unit’s own internals, and on to no diagnostic communication at all. The other adds misfires on named cylinders and a car that will not start.

Listed out like that they read like faults on half a dozen unrelated parts of the car. They are the documented behaviour of one module.

That is the practical use of the two lists. When a car of this family arrives carrying complaints that do not belong together, the combination is itself information, and it points at the module before it points at six separate repairs. That scattering is not peculiar to this ECU, which is why the symptoms a failing engine control module tends to produce sit usefully beside the two lists above.

The vehicles this unit is documented on

Bosch documents that part number on the Audi A4 3.0 TDI quattro and Avant quattro of the B8 generation, and on the A5 3.0 TDI Coupé and Sportback quattro, at 176 kW, across 2007 to 2012. Sibling EDC17CP04 units are documented on the Q7 3.0 TDI and the Volkswagen Phaeton 3.0 TDI.

Read as a whole, that is an Audi 3.0 TDI V6 controller with Volkswagen applications, and the note above covers anything beyond it. The badge on the front of the car makes no difference to what is inside the box, and this unit sits with everything else we repair with an Audi badge on it.

How a unit is handled once it reaches the workshop

A unit arriving here is logged under a reference of its own, inspected, then powered up and tested electrically before any view is taken on it. What the test finds comes back to you along with what putting it right involves, and no chargeable work starts until you have agreed to it.

The work is carried out at component level by our own engineers, in our own UK workshop, on the board that came out of your car. Nothing is sent back until it has passed a final test. The repair is covered by a 24-month warranty.

What helps most is the whole list of what the car was doing, not only the complaint that brought it in, so list them all on the Repair Form when the unit is sent in, including the ones that appear to belong to other systems. The ECU comes to us on its own; there is no need to move the car, wherever in the UK it is.

Common part numbers associated with this type of unit