# Replace ECM/ECU - does it require programming?



## jb111 (Feb 5, 2006)

My niece' car was running rough/EPC light. VW replaced and aligned the throttle body (among other things for $1350). She drove to a friend's early in the morning. Later that day it was 90 degree out. Part way home the EPC light came back on and it would not go faster than 15mph no matter how much pedal. I drove the car next day, it seemed fine............then I left the car idling for 10 mins in the sun. A few mins into my next trip, I lost power and could only go 15 mph. My friend helped me by doing this weird reset trick (something about holding down gas pedal where car is off). Anyway it worked and I drove home OK. At this point we are thinking ECU/ECM. Am I on the right track? Codes below (same ones VW should have seen from the start):
_02 Transmission

System description: AQ 250 6F
Software number: 09G927750JE
Software version: 1377
Hardware number: 09G927750JE
Coding: 0000840

Trouble codes:
01314 - Engine control module (ECM) Please read DTC
Intermittent
Priority: 2
Frequency counter: 2
Driving cycle: 0
---------------------------------------------------------------
03 Brakes

System description: ESP MK60EC1
Software number: 1K0907379CD
Software version: 0120
Hardware number: 1K0907379AD
Hardware version: H35
Long coding: 113B400D49280001881002E7922100413000

Trouble codes:
01314 - Engine control module (ECM) Please read DTC
Intermittent
Priority: 2
Frequency counter: 1
Driving cycle: 57
Mileage: 212348 km_


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## GTIVRon (Jul 24, 2009)

What are the engine codes?


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## jb111 (Feb 5, 2006)

These are the same as before they replaced the throttle body:
_01 Engine

System description: 2,5l R5/4V G
Software number: 07K906055P
Software version: 9205
Hardware number: 07K906055M
Serial number: VWX7Z0I424K036
Coding: 0000075

Trouble codes:
P0221 - Throttle/Pedal Position Sensor/Switch B Range/Performance
Intermittent
Priority: 0
Frequency counter: 1
Driving cycle: 255
Mileage: 212348 km
P0121 - Throttle/Pedal Pos.Sensor A Circ. Range/Performance
Intermittent
Priority: 0
Frequency counter: 1
Driving cycle: 255
Mileage: 212350 km_


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## GTIVRon (Jul 24, 2009)

You likely need to replace the terminal connectors on the throttle body to resolve the issue permanently. That the engine runs and you can talk to the ECU suggests it's okay.


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## GTIVRon (Jul 24, 2009)

Wait, actually yours seems to have 1 code for the throttle position sensor on the throttle body end as well as the one on the pedal end...
If you can disconnect both and send pictures of what the terminal prongs in the plugs look like. If they look the same you likely need to re-pin both. If one of them looks like the prongs are doubled up on each side and the other just looks like a blade one each side, that's the one that needs replaced.

Honestly though, I'd run a VCDS scan first as it'll tell you which sensor ID's you're working with. G187/G188 are at the throttle body and G79/G185 at the pedal.


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## jb111 (Feb 5, 2006)

I wonder if I called both Autozone/Advance Auto they don't have a VCDS. My brother/sister-in-law seem to have given up. The below pic is the pedal-side. Where does the wire terminate in the engine bay? Found a similar color pattern wire near the brake cylinder (more square plug - attached below now)


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## jb111 (Feb 5, 2006)

If we determine it's the ECU/ECM, can I buy a used one off eBay or one of the companies that resells them? Is it model to model or require programming? Thx


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## GTIVRon (Jul 24, 2009)

Send a picture showing the pins inside the connector, opposite end of where the wires go in. The throttle body connector is on the throttle body, between the engine and the radiator support.
If you determine the ECU is faulty due to these codes it's probably a miss-diagnosis. The ECU will need the immobilizer defeated or cloned from your current ECU. There are places that offer these services, I used a guy somewhat local to me.

Your problem is most likely at the throttle body connector since the heat cycling there is more severe. The problem is that they pinned the connectors with the wrong terminals and they eventually lose reliable connectivity.


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## GTIVRon (Jul 24, 2009)

Auto parts stores wouldn't have VW specific diagnostic tools. A local independent Euro or VW specialized shop would. You could try the VCDS locator (VAG-COM Diagnostic Service Locator) or your local regional forum here. As a last resort, pay the VW diagnostic fee next time the issue occurs and get their readout printed.


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## Ichabod0525 (Feb 11, 2018)

To answer your question directly; Yes a replacement ECU will need programming and will not be plug and play. Suggestion you didn't ask for; Find an independent shop equipped for diagnostic work to locate and prove the fault. This will cost you a bit but I am certian it will be a better solution for you than replacing parts that may or may not be faulty. The dealer obviously did not prove the fault but took a 'most likely' approach to fixing your neice's car. There are *other actions* you can take before opening your wallet.


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## jb111 (Feb 5, 2006)

GTIVRon said:


> Send a picture showing the pins inside the connector, opposite end of where the wires go in. The throttle body connector is on the throttle body, between the engine and the radiator support.
> If you determine the ECU is faulty due to these codes it's probably a miss-diagnosis. The ECU will need the immobilizer defeated or cloned from your current ECU. There are places that offer these services, I used a guy somewhat local to me.
> 
> Your problem is most likely at the throttle body connector since the heat cycling there is more severe. The problem is that they pinned the connectors with the wrong terminals and they eventually lose reliable connectivity.


I unplugged the throttle body - wires were taped. All colors are barrel connected to yellows


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## GTIVRon (Jul 24, 2009)

It looks like somebody already performed the needed repair but may have used the wrong connector ends again. But you can see now what needs to happen..








DIY: Throttle Body connector replacement (g/j/b material)


So I have had issues with random throttle valve pressure drop codes and rough running and limp mode. Also the car likes to randomly idle high, 1200rpm high. I also had loud boost hissing noise when boosting, sounds like a boost leak. I would get these codes; 7 Faults Found: 17705 - Pressure...




www.vwvortex.com





that link shows the part numbers for the wires you need. 
If I recall correctly, you should see a little split on either side of the connector prongs, instead of looking like 2 tabs it should like like 2 pairs of tabs.
That said, when you remove the connector that's giving problems you typically see that those blades aren't touching each other anymore. In that picture they all look tight.
See if the pedal connector looks similar or worse.


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## jb111 (Feb 5, 2006)

Thanks for the guidance. I passed this info on to a local shop. Too much going on and bundles of wires are beyond my patience


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