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CAUTION: MANY ATTEMPTED HOME REPAIRS RESULT IN IRREPARABLE  DAMAGE TO THE CPU OR OTHER NON-REPLACEABLE PARTS ON THESE CIRCUIT BOARDS. UNLESS ALL FAULTS ARE FOUND ON THESE CONTROLLERS PRIOR TO POWER-UP, THE CONTROLLER CAN BE DESTROYED MAKING AN INEXPERIENCED ATTEMPT TO SAVE MONEY A COSTLY MISTAKE!

THESE PAGES ARE NOT "HOW TO" INSTRUCTIONS AS EVERY ECM COMES TO OUR FACILITY WITH DIFFERENT PROBLEMS. OUT OF ALL OF THE ECMs WE HAVE PROCESSED, CHANGING THE CAPACITORS ALONE WOULD NOT HAVE FIXED EVEN ONE, JUST AS REPLACING A BAD OIL PUMP IN YOUR CAR WILL NOT REPAIR THE RESULTANT ENGINE DAMAGE.

From 1989 through 1994 Mitsubishi specified certain electrolytic capacitors made by Rubicon Electric. Mitsubishi, and Rubicon for that matter, didn't realize back then that these capacitors would go bad with time, especially at elevated temperatures. The liquid electrolyte in these capacitors begins leaking from the bottom plug as the rubber plastic material contracts. This liquid is VERY caustic and tends to mix with the humidity coating on the circuit boards. This action allows the electrolyte to spread and react with any metals encountered in its' path.

The interesting part to this story is that the bad capacitors continue to operate nearly as they should in the circuits they are in but the fluid causes other damage as an array of wide and varied problems start to occur. Problems vary from occasional rough running that can come and go over a period of a year to sudden catostrophic failure that fills the passenger compartment with the stench of burning fiberglass and blows a ten amp fuse in the panel.

When these units are repaired it is of the UTMOST importance to thoroughly clean the circuit boards AND the parts in the affected areas. 20-25% of the units we repair have been processed by another company in the past and have lasted just long enough to go out of warranty. These companies repair the immediate problem that stopped the vehicle, stamp it and ship it. The remaining chemical on the board continues to work away on the circuitry until the unit fails again.

This chemical action continues as a computer remains in a car or on the shelf at an auto recycler to be sold by an unsuspecting counter man to an unsuspecting customer. 

The following e-mail was received on March 29, 2002 after initial dialogue via email on the 28th and is typical:

i actually have 2 of the ecu computers for the 90 mits pickup
i took a chance and purchased a used one at a salvage yard with "no guarantee" for 150.00, but of course it was dead also
they absolutely refused to take it back, saying i bought it "as is"
is there any way i can trade both of them in and maybe get a discount?
i would really appeciate it
i wish i would have found your website before i wasted my money at that salvage yard
thanks
dan

The following pages partially document the proper repair process:

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