ECU Rebuild Instructions

Click here to view or download ECU rebuild instructions in PDF Form ECU Rebuild Instructions

CAUTION: (If applicable to your ECU), BE VERY GENTLE with flexing the ribbon cables that connect the 2 main boards. They will take a normal amount of flex required to open up these boards flat the rebuild, but avoid excessive bending.

Parts and tools required:

  • ECU
  • capacitor kit
  • Digital multimeter
  • Solder
  • Soldering iron or soldering station, 60W max – no soldering guns!
  • Solder sucker
  • Canned air duster or similar
  • Flush cutters
  • 91%+ isopropyl alcohol

Rebuild Procedure: (follow all precautions of working on an electrical system when removing the ECU, including disconnecting the negative battery cable and disabling the airbags, if applicable!)

CAUTION: – static electricity can kill an ECU – wear the anti-static wrist at ALL TIMES during the rebuild process.

BEFORE BEGINNING take photos of original capacitor position and make a diagram of cap sizes & placement.

  1. Remove old caps by heating the solder with the soldering iron by pulling gently away from the board. Use the solder sucker to remove solder from the holes after removing the caps.
  2. Gently clean the board under the old capacitors with isopropyl alcohol.
  3. Inspect the copper traces on the board for damage to insure that they are still intact. If significant damage is observed, check for trace continuity with a multimeter. If the traces are broken, they can be carefully reconnected with the trimmed leads (that will be generated in part 6)
  4. Inspect de-soldering job.
  5. Solder in new caps, double checking polarity (+/- orientation) – using rosin core solder.
  6. Trim leads on reverse side of board of each installed cap with flush cutter.
  7. Clean board with 91% or higher isopropyl alcohol.
  8. Inspect soldered connections for complete solder flow and electrical continuity.
  9. Gently clear any clipped leads or foreign objects from the board with air duster or compressed air.
  10. Reassemble the ECU and reinstall it in the vehicle.
  11. Once ECU is reinstalled into car and everything is reconnected, reconnect the negative battery cable.
  12. BEFORE cranking the engine, turn the ignition switch to the RUN position for 30 seconds.