Diagnosing A Solid MIL

A solid check engine light (with service check connector jumpered) is for an internal rom reading error within the ECU. If you receive a solid check engine light on a stock/ unchipped factory ECU, then the internal processor is most likely bad and the entire ECU should be replaced. If you receive a solid check engine light on a socketed/chipped ECU, the following information will help you diagnose and correct the problem.

Causes for a solid check engine light on a chipped ECU:

> Damaged ROM programming on your 28 pin chip. (either corrupt file, or incorrect addressing on chip) - WE VERIFY ALL OF OUR CHIP DATA BEFORE SHIPPING SO THIS IS NOT LIKELY THE ISSUE IF YOUR USING ONE OF OUR CHIPS!

> Poor connection between 28 pin chip and 28 pin socket (bent pens, chip in backwards, lever not fully closed on ZIF socket, etc)

> Poor ECU soldering of the 28 pin socket/zif or the 74HC373chip.

Step One: verify soldering of 28 pin/zif socket and 74HC373 chip

To check soldering, remove the back cover on your ECU and inspect for any pins that are not fully soldered. We recommend applying a light layer of solder flux and re-heating all solder joints to make sure you don't have any cold solder joints.

Step Two: Check 28 pin chip connection with 28 pin socket/zif

NOTE: The half moon notch on ALL chips MUST face the ECU connectors as shown below:

Step Three: If programming your own chip. Verify that the program burned onto your 28 pin chip is valid.

If using a 512k chip (as in our 27SF512 chips), be sure your chip programmer is set to address the chip correctly. If using a Moates Ostrich, Demon, or Hondata S300, be sure the program is correctly uploaded to your emulator.