Volkswagen Passat Forum banner
1 - 5 of 5 Posts

·
Registered
Joined
·
1,482 Posts
Discussion Starter · #1 ·
Trading ECU's tommorow. I have a copy of the APR ECU removal.pdf. I read the ECU removal post in the Info Forum here (FIX THE PIC's!!!!) and it went a little deeper then the APR one. Is disconnecting the battery really needed?

(and reading the instructions here...how are you going to do step 2 (run wiper) if you performed step one? (disconnect Battery Neg wire) ) :D

And if I disconnect the Battery, will I need to dig up and use my Radio code? (stock HU still for a few more weeks)

Lastly, where is the Port located that I plug the Vag unit into?

Both cars are '99 1.8T's. Recoding each to new Tranny code and switching. (upgrading to Chipped ECU finally)

Thanks!!!!!!!!!!!!!!
 

·
Registered
Joined
·
3,341 Posts
here is the easy method:

1. key out of ignition!

2. no need to disconnect battery.

3. remove all screws in the ecu case except the hidden rear one.

4. gently lift/flex the ecu case cover, use a long screwdriver to release the spring steel clip on one side. then reach in and unhook the other side.

5. gently lift the ECU up/forward, use your hand to guide the wiring harness out. only pull it out far enough to access the connectors.

6. unhook the connectors, the ECU is free!

on your car (no cowling) this should take ~2 minutes. :thumbup:

the vag port is undert the steering wheel, it is a purple connector.
 

·
Registered
Joined
·
1,009 Posts
I have changed the ECU a few times on my '99 and I have never disconnected the battery. The instructions I got from Neuspeed did not require the battery to be disconnected. If you do remove the power from the battery you will need to have the radio code.

Also, it has not been necessary to run the wipers. If you have a 1/4" drive rachet and socket to fit the ECR cover screws (8 mm ?) you can get the back screw out pretty easily. The wiper mechanism does not interfere.

The OBDII port is under the dash, below and left of the steering column. You need to get very low and look upward at it to see well enough to line up the VAG-COM cable.
 

·
Registered
Joined
·
3,184 Posts
I have swapped the ecu many times and never disconnected the battery. I would advise you remove the back screw on the ecu cover. Trying to do the clam shell deal will make it difficult to see what you are doing. I removed the back screw through the little hole just using a 6" extension. Just make sure you don't drop the screw. I haven't put the back screw in since the box seems pretty tight with just the four screws in there.
 

·
Registered
Joined
·
1,482 Posts
Discussion Starter · #5 ·
Thanks guys!

I already pre-removed the rear screw last week when I verified my ECU #. Left it out to speed up the swap. I was able to get at it with a box end wrench, I will put it back in post swap.

Have to get the resonator removed and Glasspack installed today too!
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top