VW / Audi / Seat / Skoda (VAG) Bosch EDC17CP14 Engine ECU Repairs

Type: Bosch
Fits: VAG – Audi / Seat / Skoda / Volkswagen (VW)
Fuel: Diesel
Ref: ECUT338325

Note: This ECU may also fit other models.

The Bosch EDC17CP14 is the engine control unit on Volkswagen and Audi 2.0 TDI common-rail diesels, and it holds the fuelling, air and starting decisions for the engine it sits on. Almost every code it stores is an accusation about something outside itself: a sensor, a valve, a circuit it is watching. One code is not, and this page is about that one — what P1603 means here, why it is harder to act on than it looks, and what settles it. It is a diesel engine ECU. Testing one in full and rebuilding it is our own engineers’ work.

What P1603 says that other codes do not

P1603 appears in Volkswagen’s own numbering as 18011, and it is documented there as control unit faulty. No component is named in it, because none is being accused. The unit has run its own checks and recorded a failure of itself.

A code raised against an intake flap points at a part. This one points at the module doing the reading.

Why the most specific code is the hardest to act on

With a circuit code there is somewhere to go and something to measure: the named part, its wiring and its connections, tested against a known figure.

P1603 offers none of that. The accusation sits inside a sealed box, so the ordinary path — test what the code names, then work back from there — has nowhere to run. A garage can prove everything around the ECU healthy and be no nearer to knowing whether the ECU is.

So the code most specific about this ECU is the one that leaves a workshop with the least to do.

The fault lists published for these two part numbers

Two published fault lists cover the exact numbers in the table below. Against 0281015823, the Audi A3 unit, the documented complaint is internal failure: the engine cutting out unexpectedly, a non-start condition, and a scan that typically returns P1603. Against 0281015335, the Volkswagen Scirocco unit, the record reads the same — ECU failure, intermittent engine cut-outs or a complete failure to start, with P1603 recorded in most cases.

A third list, compiled against the EDC17CP14 as a type rather than one part number, by a specialist working from its own returns, names three common problems: no injector signal, an error on the signal to the turbo, and P1603 (18011), control unit faulty.

The manufacturer publishes its own set of error patterns against 0281015335, and it reads as follows.

• P2004 / P2006 — intake manifold flap, bank 1, hanging open or hanging closed
• P2015 — intake manifold flap position, implausible signal
• P0403 — exhaust gas recirculation valve
• P0602 — control unit, program error
• P0606 — control unit
• No control to the injectors
• No communication with the ECU, fault-code reading not possible

It is here so that a technician holding one of those codes can find it against this unit. Two of the entries point the same way as P1603: P0602, a control unit program error, and P0606, control unit.

The code does not come from one place. It is published against each of the two part numbers, and again against the whole type by a different specialist. Separate lists, different vehicles, the same fault on the same hardware — that is about as close to evidence as this trade gets. It does not tell you that your unit has failed; it tells you what one of these tends to say when it does.

What settles a control-unit fault

A self-accusing code is still not proof on its own: poor supply voltage, a bad earth, or a unit that has recently had software written into it can all produce control-unit faults. Check those basics, and establish whether anything has been flashed into the unit, before going further.

After that, one measurement is left. The unit has to be run on a bench under load — powered away from the vehicle, taken through its operating conditions and made to do real work rather than sit idle. A fault that exists only as a line in a scan report either reappears there or it does not.

The two part numbers on this page

0281015335, Volkswagen’s 03L 906 022 KD, is documented on the Scirocco 2.0 TDI at 103 kW, built between October 2008 and November 2010. 0281015823, Audi’s 03L 906 022 LS, is documented on the A3 2.0 TDI CR across 2008 to 2013. Beyond those two, the EDC17CP14 appears across the group’s 2.0 TDI common-rail engines generally, which is what the note above covers.

If the number on your unit is not one of these two, it may still be one we handle. Other Volkswagen engine ECUs we take in are set out on their own, as are the Audi models whose engine ECUs come to us.

The repair, and what it covers

A unit that arrives is logged, inspected and tested under power before we form a view on it, and what the test shows goes back to you with what putting it right involves. Nothing chargeable begins until you have agreed to it.

The work is component-level, done by our own engineers in our own UK workshop, on the board that came out of the car. A unit leaves only after it has passed final testing, and whatever we repair is covered for 24 months. Tuning, remapping, cloning and immobiliser work sit outside what we do.

Only the unit travels, and it reaches us from every part of the UK. Send it in with the codes exactly as they were read, because the Repair Form asks which codes were stored, and on this ECU that answer decides where testing starts.

Common part numbers associated with this type of unit