ECM Replacement

Make sure you have the anti-theft code for the radio, then write down the audio presets.
Turn the ignition switch OFF.
Wait 1 minute. If the radiator fan is running, wait 1 minute after the radiator fan stops.
Disconnect the negative cable from the battery.
Pull the passenger's side carpet back to expose the ECM (A).

Fig 1: Pulling Passenger's Side Carpet Back To Expose ECM
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Remove the ECM cover (B).
Lift the lower edge of the ECM cover off of the lower studs. Make sure the ECM is not touching the studs.
Lift the upper edge of the ECM cover enough to clear the upper studs, then pull the cover down away from the evaporator drain tube.
Remove the ECM from the cover.
Disconnect the ECM connectors.
Install the ECM in the reverse order of removal.
Turn the ignition switch ON (II).
NOTE: For 2005-2006 models: DTC P0630 "VIN Not Programmed or Mismatch" may be stored because VIN has not been programmed into the ECM; ignore it, and continue this procedure.
For 2005-2006 models: Input the VIN to the ECM with the HDS.
Rewrite the immobilizer code with the ECM replacement procedure in the HDS; it allows you to start the engine.
Do the ECM idle learn procedure (see ECM IDLE LEARN PROCEDURE ).
Remove the No. 15 (40 A) fuse from the under-hood fuse/relay box.
If the IMA battery level gauge (BAT) displays no segments, start the engine, and hold it between 3,500 rpm and 4,000 rpm without load (in Park or neutral) until the BAT displays at least three segments.
Reinstall the No. 15(40 A) fuse.
Do the start clutch calibration procedure (see START CLUTCH CALIBRATION PROCEDURES ).
Enter the anti-theft code for the radio, then enter the audio presets, and set the clock.