ECM/PCM Update

PCM Updating

Use this procedure when you have to substitute a known-good PCM in a troubleshooting procedure. Update the PCM only if the PCM does not already have the latest software loaded.

NOTE:
- Do not turn the ignition switch OFF while updating the PCM. If you turn the ignition switch OFF before completion, the PCM can be damaged.
- To ensure the latest program is installed, do a PCM update whenever the PCM is substituted or replaced.
- You can not update a PCM with the program it already has. It will only accept a new program.
- Before you update the PCM, make sure the vehicle's battery is fully charged.
- To prevent PCM damage, do not operate anything electrical (audio system, brakes, A/C, power windows, moonroof, door locks, etc.) 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 data link connector (DLC). This will prevent PCM damage.

1. Turn the ignition switch ON (II). Do not start the engine.




2. Connect the HDS or the Honda Interface Module (HIM) to the data link connector (DLC) (A) located under the driver's side of the dashboard.
3. Check if the software in the PCM is the latest as described on the HIM label and in the PCM update system.
4. If the software in the PCM is not the latest, do the PCM update procedure as described on the HIM label and in the PCM update system.
5. Do the PCM Idle Learn Procedure.
6. Do the CKP PATTERN Learn Procedure.

PCM Substitution for Testing

1. Remove the PCM.
2. Install a known-good PCM.
3. Rewrite the immobilizer code with the PCM replacement procedure in the HDS; it allows you to start the engine.
4. After completing your tests, reinstall the original PCM and rewrite the immobilizer code with the PCM replacement procedure in the HDS.