Hi guys, I wonder if you can help me. I have a p72 obd1 which has been socketed and chipped for a b16. I want to return it to stock and this involves cutting the resistor on J1. Except mine does not have a resistor to snip on the front. I've checked out the back and there is a resistor (?) over J1 - would this just need desoldering? I've attached a link to a picture which is similar. (The only difference is that he has attached a switched, and mine has a ohm resistor (?) on J1. Like a little brick lol

http://cars.homenetcs.co.uk/honda-ci...72_J1-caps.jpg

I'm stumbling in the dark here!

 

Yes the J1 on JDM/small square ECU's is a surface mount resistor on the underside. It is a 0 ohm resistor, aka jumper. Remove/desolder it and your ECU will no longer read from the socket ROM chip. It will read from the stock ROM.

 

Awesomeness. Thanks Ghost Accord. Is it possible to get a removable jumper so I can switch between maps? Or a guide on installing a switch? Cannot find one at all!

 

There isn't really room between the ECU case cover and the bottom of the main board to install a removable jumper. As far as installing a switch. You would have to solder 2 wires, one to each solder point of J1. Then drill a hole ether through the main board or the side of the case. Then run the wires through the hole and hard wire the two wires to an automotive (12v) toggle switch.

Some people install the toggle switch into the side or cover of the ECU. I have done both but have never made a DIY of the procedure.

 

I install a red jumper in position J1 on all the ECUs that I chip. Makes it a breeze to enable/disable the chip.

 

What about those pesky small box JDM ECU's that use surface solder components? I think that is what the OP is up against.

Are you still able to use a thru hole style jumper on the surface solder J1 of a JDM ECU?

 

My bad - I didn't look at the pic...