Clearing Diagnostic Trouble Codes

HDS Clear Command

The ECM stores various specific data to correct the system even if there is no electrical power, such as when the battery negative terminal or No. 6 ECU (ECM) (15 A) fuse are disconnected. Stored data based on failure parts should be cleared by using the "CLEAR COMMAND" of the HDS, if parts are replaced.

The HDS has three kinds of clear commands to meet the purpose. They are DTC clear, ECM clear, and CKP pattern clear. DTC clear command erases all stored DTC codes, freeze data, and readiness codes. This must be done with the HDS after reproducing the DTC during troubleshooting.
ECM clear command erases all stored DTC codes, freeze data, readiness codes, and all specific data to correct the system.

DTC CLEAR

1. Clear the DTC with the HDS while the engine is stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II). Wait for 30 seconds.
4. Turn the ignition switch OFF, and disconnect the HDS from the DLC.

ECM RESET

This command clears stored specific data from each vehicle, such as DTCs, freeze data, and readiness codes.

1. Reset the ECM with the HDS while the engine is stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II). Wait for 30 seconds.
4. Turn the ignition switch OFF, and disconnect the HDS from the DLC.

How to End a Troubleshooting Session (required after any troubleshooting)

1. Reset the ECM with the HDS.
2. Do the ECM idle learn procedure.
3. Turn the ignition switch OFF.
4. Disconnect the HDS from the DLC.

NOTE: The ECM is part of the immobilizer system. If you replace the ECM, it will have a different immobilizer code. In order for the engine to start, you must rewrite the immobilizer code with the HDS.