2007 GTI Common Rail swap

I will be swapping a 2009 Common rail Tdi into a 2007 GTI. There are a few things I need to know. Or if there is anything I might be missing.

My main concern is the in tank fuel pump wiring. What is the simplest way to making this work? I'll have the whole car and suppose I could swap the whole harness, but it's a 2 door gti so I'm sure I will run into problems there.

Second the ecu wiring on the vehicle side, is that the same? Can I just plug the cluster in, and swap the key fobs?

Both cars are 6 speeds so won't run into trans issues.

I'm thinking I can make the gti intercooler work, since mine was destroyed. Maybe with some custom silicone hoses. But I might upgrade to a cts or similar intercooler.

I plan on dpf deleting, and CP3 pump at the same time. I'm just doing some brainstorming before I get the car back and torn apart.

Thanks in advance for any insight!

The Ecu plugs may be the same, but the engine harness will be very different. Unless you are very adept at reading and understanding wiring diagrams, you might be in over your head.

For wiring, the best thing to do is get schematics of both cars and check every pin location and what they do. I installed a BHW (2004 Passat 2.0 PD) motor in place of a 2.7T V6 gasser in a 2001 Audi Allroad. All the firewall harness plugs were the same but 50%-60% of the pins performed different functions. It was a matter of moving wires around in the harness to do what I needed. It wasn't a huge deal, but tedious and time consuming for sure.

FWIW, I used the gasser fuel pump in the AllRoad and installed a "T" in line to relieve the higher pressures.

I just put a CBEA into a 69 Beetle pickup conversion. I used the original car's harness and made it a standalone. It can be done, but as vwztips has said you will be very intimate with the ecu pinouts.

As far as fuel pumps go, the lift pump is in the tank and you may be able to merely swap tank units and adapt the wiring up front. The Aux fuel pump is mounted on the engine and just needs the appropriate power supplied from the fuel pump relay. On my beetle swap I just used a standard inline fuel pump for the lift pump. Low pressure type used for carburetor applications.

The common rail Ecu communicates on a Can line, so the Can gateway may need to be swapped and adapted too.

Yea I'm going to swap the fuel tank and lines. I have he whole car the I'm not asking about the engine harness. Mainly the MAF, o2 sensors, and egt sensors that would be on the larger plug on the ecu. The aux pump and dpf pressure sensors are also on this harness but, I won't be needing all that so I just won't swap those over.

The glow plug controller is also not part of the main engine harness. I glanced at some diagrams and it looked like it tied into the fuel pump relay.

I haven't been able to spend much time with my head in a book with my neck pain from the wreck. I'm going to rip the motor and trans out tomorrow and strip the harness back to separate the glow plug, get, o2, etc and take note as to what wires are in what pins. I suspect the o2 sensors, and maf at least will be in the same pins on the gti's harness

The small connector on the Ecu harness will remain basically untouched as it goes direct to the engine, all of the work will be on the larger connector harness.
I had the entire harness for the car and painstakingly separated out the necessary wires without cutting them. Many wires come from the fuse panel A/B. You will need the two fuel pump relays and harness, and the glow plug harness. I was able to leave them uncut too for the most part.
If you do a DPF and EGR delete you will only need MAF and N75 and EGT 1 wires run up to the engine apart from small ECU harness and two other sub harnesses. I am thinking a Maf delete may be possible with EGR delete too, don't know for sure yet as in development stage still. Got it running and driving, code stomping is next as it is still a stock ECU and is running in limp mode due to missing pieces. I have all codes cured for parts that remain so the ECU needs to have a lobotomy.

You say the fuel pump relays and uncut for the most part. They are on the interior fuse box correct? Were you able to pull the plug through the firewall?

The gti I have uses a fuel pump module, but I'm assuming it can be left in place as long as it turns the pump on when the car is on.

I scrapped out the entire car as it was badly wrecked. I took the whole harness out as intact as possible. If I remember we pulled the harness through to the interior side after removing the dash. If you don't want to go that far a little cutting would be needed.

The TDI tank pump, or fuel pump module is a much lower pressure pump. I suspect they will interchange between tanks. The tank lift pump is controlled directly from one of the fuel pump relays. You could probably use existing wires.

I'm swapping the entire tank. I took the liberty today of putting the diesel that was in it into my daily. Haha




I'm just curious if the gti already has a fuel pump relay system maybe it will work? At most just re-pinning of the control wire to turn the pump on would be needed. As for the maf, and egt's I want to say that on a mk5 PD I traced the n75 (which would be on that same harness as egt sensors) goes down to the plug under the driver headlight. If this is the case that wiring can be separated from the body harness and either integrated into the main engine harness or over laid into the gti.

The fuel pump should be the only thing that goes through the fire wall that I should have to worry about. (Hoping ?)