Swapped ecu now car won't start

ZimZum

Member
Joined
Nov 30, 2018
Location
New Jersey
TDI
Mk4 golf
2000 golf tdi

I did the 5 speed swap with a donor car (2002 golf tdi)
I changed all the engine bay wire harnesses and swapped ecu as well. Now it will turn over but not start.
Do I need to swap the cluster also?
Or do I need to swap the ignition key?
 

mr.loops

Veteran Member
Joined
Nov 24, 2010
Location
Kelowna
TDI
2002 jetta, 2003 Bora 1.8T
Does it start and run for 5 secs and then shut off? If so, then you have a immo issue. You need the ECU to match your key fob and cluster in order for your car to run. Not a big deal as you can get an immo defeat for your ECU.





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mrfiat

Veteran Member
Joined
Mar 24, 2008
Location
Los Ranchos, NM
TDI
2003 Jetta TDI (Reflex Silver) , 2003 Jetta TDI Wagon (Black)
Just curious, why did you swap the harnesses? No need for that with the 5-speed swap.
 

Alchemist

Veteran Member
Joined
Nov 3, 2007
Location
Lethbridge, Alberta
TDI
'04 ALH Golf
There was no need to change the ECU. Just swap your original ECU back in and recode it for manual transmission with VCDS.

I just realized the difference between the 2000 and 2002 in the glow plug system. This complicates things a bit, making the original harness and glow plug relay more attractive.

When coded for manual transmission, the ECU is also looking for the coolant glow plug relays. If they are not installed, it will set a trouble code and light the MIL. It is only the relays that are monitored, not the glow plugs.
 
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ZimZum

Member
Joined
Nov 30, 2018
Location
New Jersey
TDI
Mk4 golf
So I can put the original ecu back in the car with it still having the wires from the donor car?


I swapped all the harnesses because I don't like to cut and splice wires on what will be my daily driver again (120 miles a day)


Where is a good place to get a vcds? I don't have a lot of money and my laptop needs more love than the car does at this point lol.

Or is there someone in New Jersey that can help me out with that today?
 

ZimZum

Member
Joined
Nov 30, 2018
Location
New Jersey
TDI
Mk4 golf
Switched out ignition cylinders and cluster and it fired right up!!!

Now I have 3 codes to deal with
P1441
P0671
P0673

I know that p1441 is the egr

The question is what causes the glow plug codes?
I swapped the GP harness with the rest of the wires and tucked away the original 2 wire connector
Should I change back to the original GP harness(2wire) or will the manual CPU not work with it?

I already installed the donor coolant flange with GPs. All hooked up with the donor harness

And now I'm leaking from the lower seal on my injection pump
 
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ZimZum

Member
Joined
Nov 30, 2018
Location
New Jersey
TDI
Mk4 golf
Also can I swap the chip in the keys to retain my remote?
Or will I damage the chips and be stuck again?
 

ZimZum

Member
Joined
Nov 30, 2018
Location
New Jersey
TDI
Mk4 golf
Just curious, why did you swap the harnesses? No need for that with the 5-speed swap.

Another benefit for swapping the harnesses is not having to wire in the clutch cancel switch.
Also I hardly ever use my cruise control(which works) so tapping the brake to disengage it to shift is no big deal to me
 

mrfiat

Veteran Member
Joined
Mar 24, 2008
Location
Los Ranchos, NM
TDI
2003 Jetta TDI (Reflex Silver) , 2003 Jetta TDI Wagon (Black)
Wiring in the clutch cancel switch isn't that big of a deal. Just follow the FAQ and it will work fine. I would go back to the original ECU and (maybe) the original wiring harness.
 

ZimZum

Member
Joined
Nov 30, 2018
Location
New Jersey
TDI
Mk4 golf
When I put the correct relay in it fired right up. I did not connect anything for the neutral saftey switch

My only issues now are the check engine light for the glow plugs and the connector for my reverse lights has a short in it
 
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