JDM OBD I ECUs

This series of ECUs is about 2/3 the size of the US ECUs and uses

mostly surface mount technology. This series of computers also has

the ROM and microprocessor combined. A fine tipped soldering iron

and lots of soldering experience is needed to install the surface

mounted 74HC373 chip.

1. Desolder all holes for the components.

2. Solder in a 28 pin DIP thru-hole type ROM socket.

3. Solder in the 74HC373 SMD Chip. If the the IC chip is the wide

package type you need to bend the leads to line up. Use flux when

soldering. Pin one is at the lower right hand corner in the diagram.

4. Solder in J1. This jumper can activated by utilizing an unused resistor lead or

extra section of spare wire. This location is on the backside of the ECU

motherboard.

5. Insert 28 pin DIP ROM in the proper orientation and start the

car.

Caution: If you plug in an EPROM or EEPROM backwards it will overheat

and erase or damage the device.

Cut J1 to return the ECU to stock.

pictures courtesy of Jason Katman/FF-SQUAD.COM .