How to Update the TCM
How to Update the TCMNOTE:
^ To ensure the latest program is installed, update a TCM whenever the TCM is substituted or replaced.
^ You cannot update a TCM with the program it already has. It will only accept a new program.
^ Before you update the TCM, make sure the vehicle's battery is fully charged.
^ To prevent TCM damage, do not operate anything electrical system; audio system, brakes, air conditioning, power windows, moonroof, and door locks, during the update.
^ If you need to diagnose the Honda Interface Module (HIM) because the HIM's red (# 3) light came on or was flashing during the update, leave the ignition switch in the ON (II) position when you disconnect the HIM from the DLC. This will prevent TCM damage.
1. Turn the ignition switch ON (II). Do not start the engine.
2. Connect the Honda Interface Module (HIM) to the DLC located under the dash behind the center console.
3. Update the TCM according with the procedures described on the HIM label in the TCM update system. If the software in the TCM is the latest, replace the TCM.