Bew to alh swap

It's been a long time since I've posted. Mostly because my 03 wagon has been problem free for 3 years now. (305k)
My wife's 04 wagon 5 speed on the other hand just started knocking. I bought it cheap with a broken oil pan. It went 10k after repairs but the bearings must've suffered damage.
I have a spare alh engine and a complete 2001 golf tdi auto.
I would like to swap the alh into the wagon. Is there a thread on this swap already? I'm sure the computer and engine harness need to be swapped.
But not sure of the cluster or what needs to be done with the security system. Luckily I live in pa so emissions is not a concern.
Thanks in advance. Gstone.

I have looked into this as well and plan on doing . I will do a full post when I start but is going to be awhile many other projects to complete first. I live in harrisburg area and this is what I no so far for your car the alh ecu must be recoded to manual and unlocked as the ignition switch and gauge cluster all work together for the mobilize system. Your harness from alh will need to be modified because of auto to manual would be easier to use manual hardness since reverse light and starter wiring and speed sensor is already in the manual harness. As for the conversion I have not compared car wiring yet where the engine harness plugs into car all the plugs are the same but wiring could be different and have to be modified. You can pm me with your number or email me at btketter@ptd.net and I can tell you what I no alot of research on my part and not much imfo on the net . Good luck

Either of you guys pull this conversion off yet? I am sitting on a fresh ALH and am sick of all the headaches and lack of fuel milage the BEW provides.

I have checked the wiring, and it looks like changing the ECU and engine harness is all that's needed.

The immobilizer is something that a tuner can eliminate and add a bit of zip at the same time. I have an ALH from an automatic, and it is getting very close to replacing my BEW.

Alchemist said:

I have checked the wiring, and it looks like changing the ECU and engine harness is all that's needed.

The immobilizer is something that a tuner can eliminate and add a bit of zip at the same time. I have an ALH from an automatic, and it is getting very close to replacing my BEW.

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what has to be swapped on the short side connector ?

car cannot ever be plugged in for e check... would not be correct diesel for model year... and there places in pa that do..

Time permitting, I hope to do a proof of concept experiment next week. This will involve the ALH hanging on a shop crane while the wire harness runs cross country to the plenum connectors. If it starts, I will then change the instrument cluster and use a matched key for the immobilizer. Run times will have to be short due to no coolant, but a lot can be learned in 10 seconds.

The coolant glow plug relays will need to have the wires from the ECU repinned, and the MAP/IAT sensor will probably have to be changed along with the intake plumbing and MAF.

According to all I have seen in the wiring diagrams it should work, but I am sure some nasty little details will emerge.

Stay tuned for further developments.

Keep the cluster and just adapt the ECU to the car.

turbocharged798 said:

Keep the cluster and just adapt the ECU to the car.

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This is just the experiment stage to see how much is involved in making it work. I have the complete harness, cluster, keys etc. from a donor car, so it will be easy to do it as a test. This will allow checking on canbus vs individual leads for things like tach, MIL and GP lights.

I am pretty sure the plenum connectors will be plug and play, but it needs to be tested.

SUCCESS!!!!

As I had hoped, it was Plug N Play. The plenum connectors and the 14 pin connector near the battery plugged in and it worked just the way it should.

I used a 038 906 102 FD ECU from an 02 Jetta with the cluster in the 04 Golf, and no problems showed up. MIL and GP lights come on as expected, tach works and VCDS communicates with the ECU. Immobilizer prevented me from doing much more by way of testing, but I don't see any electrical problems ahead.

The biggest issues are likely to be the A/C compressor and P.S. lines.

Alchemist said:

SUCCESS!!!!

As I had hoped, it was Plug N Play. The plenum connectors and the 14 pin connector near the battery plugged in and it worked just the way it should.

I used a 038 906 102 FD ECU from an 02 Jetta with the cluster in the 04 Golf, and no problems showed up. MIL and GP lights come on as expected, tach works and VCDS communicates with the ECU. Immobilizer prevented me from doing much more by way of testing, but I don't see any electrical problems ahead.

The biggest issues are likely to be the A/C compressor and P.S. lines.

Click to expand...

sweet!!.... i'm pretty excited about this... after my six speed swap i'm going to start gathering parts for the PD to VE transformation ... another thing to consider is the lift pump wiring ... the pd has a relay for this... is there possibly an existing trigger in the edc15 ecm that can be used for the relay or should we just use the fuel stop solenoid wire ?

this all sounds so backwards to me...I mean I get the reasoning behind it but it just seems wrong...

The wiring diagram shows a Violet/Yellow wire from T121-80 to T10W-7 which is the fuel pump relay lead, but I didn't hear the pump. My suspicion is the hardware is in place, but the firmware doesn't activate it. I will test further today, but I suspect it will require the N109 connection to make the pump relay work.

nitec said:

this all sounds so backwards to me...I mean I get the reasoning behind it but it just seems wrong...

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better FE and cheaper/easier to mod along with simpler diagnostics

Alchemist said:

The wiring diagram shows a Violet/Yellow wire from T121-80 to T10W-7 which is the fuel pump relay lead, but I didn't hear the pump. My suspicion is the hardware is in place, but the firmware doesn't activate it. I will test further today, but I suspect it will require the N109 connection to make the pump relay work.

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or possibly the wire just dead ends at the white connector ?... i can dig out an old harness and check

The wire from T121-80 does go to T10W-7, but it doesn't do anything. No power, no ground, it just sits there looking stupid.

This leads us to use the fuel cut off solenoid to operate the fuel pump relay, BUT the relay needs a ground to activate, not the power available at the solenoid.


This should work to make the cut off solenoid power operate the fuel pump relay.



Jim, you might recognize parts of this circuit. What works, works so keep using it.

Alchemist said:

The wire from T121-80 does go to T10W-7, but it doesn't do anything. No power, no ground, it just sits there looking stupid.

This leads us to use the fuel cut off solenoid to operate the fuel pump relay, BUT the relay needs a ground to activate, not the power available at the solenoid.


This should work to make the cut off solenoid power operate the fuel pump relay.



Jim, you might recognize parts of this circuit. What works, works so keep using it.

Click to expand...

i do recognize that little gem ... it's still operating my CEL after nearly five years and over 80k miles !

Nice! I prefer the ALH to the BEW as well, yet ironically I've sold maybe 3 BEW long blocks in the last few years and probably 20 ALH long blocks in that same time period.

I still think the ALH is more reliable, just interesting the sales numbers between the two. Congrats on the swap!
-BB

It has taken a long time to get this done, but it works!

All the mechanical stuff was straight forward bolt up and go.

As expected, both AC lines to the compressor had to be changed as well as both lines to the PS pump. Also had to change lower rad hose and coolant lines on the firewall. Upper rad hose is direct fit. I am still using the BEW rad and AC condenser, as they appear to be the same.

Vacuum system is very simple on mine since there is no N18, just N75 and ASV, but it does require the ALH brake booster tube.

I used a relay to change the +12V from the fuel shutoff solenoid to ground for the fuel pump relay. The BEW TPS works with the ALH ECU, and the cluster is fully functional without any modification or wiring changes.

Malone Stage 3, 11mm pump and PP520 nozzles. Happy!

I have a 2000 Beetle with the BEW, I would LOVE to put it in my 2004 Jetta (ALH), how much modifying do you think i would have to do?

I think you meant that the other way around ALH is in the beetle.

Alchemist said:

It has taken a long time to get this done, but it works!

All the mechanical stuff was straight forward bolt up and go.

As expected, both AC lines to the compressor had to be changed as well as both lines to the PS pump. Also had to change lower rad hose and coolant lines on the firewall. Upper rad hose is direct fit. I am still using the BEW rad and AC condenser, as they appear to be the same.

Vacuum system is very simple on mine since there is no N18, just N75 and ASV, but it does require the ALH brake booster tube.

I used a relay to change the +12V from the fuel shutoff solenoid to ground for the fuel pump relay. The BEW TPS works with the ALH ECU, and the cluster is fully functional without any modification or wiring changes.

Malone Stage 3, 11mm pump and PP520 nozzles. Happy!

Click to expand...

very cool ! so the relay is just going NC on the open leg when you shut it down and 12v to pump on the NO with key on ?

When the added relay gets 12V from the ECU-N109 lead, it sends a ground to the stock fuel pump relay to run the pump.

Alchemist said:

When the added relay gets 12V from the ECU-N109 lead, it sends a ground to the stock fuel pump relay to run the pump.

Click to expand...

very good!