Clearing Diagnostic Trouble Codes

Honda PGM Tester or HDS Clear Command
The ECM/PCM stores various specific data for the vehicle even when there is no electrical power such as when the battery negative terminal is disconnected or No.9 back up fuse is removed. But stored data based on failed parts should be cleared by using the "CLEAR COMMAND" on the Honda PGM tester or the HDS, if parts are replaced.

NOTE: The ECM/PCM overwrites data after the ignition switch is turned OFF and then ON (II). Execution of a CLEAR COMMAND will not occur if power to the ECM/PCM is interrupted after the clear command, and for up to 5 minutes after the ignition switch is turned off. During this 5 minute period, do not do any of these actions:

- Disconnect the battery.
- Replace the ECM/PCM or disconnect its connector.
- Remove the No.6 IGP (ECM/PCM) (15A) fuse from the under-hood fuse/relay box.
- Remove the PGM-FI main relay 1.
- Remove the battery wire from the under-hood fuse/relay box.
- Disconnect the connector (C101) between the dashboard wire harness and engine compartment wire harness.
- Disconnect the G1 terminal from the transmission housing.

DTC CLEAR
This command clears the DTC, FREEZE DATA, and Readiness Codes. This procedure must be done with a Honda PGM Tester or HDS after reproducing a DTC during troubleshooting.
1. Do the DTC CLEAR in the CLEAR MENU of the Honda PGM tester or the HDS with the engine stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II). Wait for 30 seconds.

ECM/PCM RESET

This command clears stored specific data from each vehicle such as DTC, FREEZE DATA, and Readiness Codes. It does not clear CKP PATTERN data.

1. Do the ECM/PCM RESET in the CLEAR MENU of the Honda PGM tester or the HDS with the engine stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II). Wait for 30 seconds.

CKP PATTERN CLEAR/CKP PATTERN Learn Procedure

This command clears only the stored CKP PATTERN data and must be done when the CKP sensor is replaced or misfire code required. This procedure allows the learning of a new CKP sensor pattern.

Enable Criteria
ECT at 176 °F (80 °C) or higher.

Procedure
1. Do the CKP PATTERN CLEAR in the CLEAR MENU of the Honda PGM tester or the HDS with the engine stopped.
2. Turn the ignition OFF.
3. Turn the ignition ON (II), and wait for 30 seconds.
4. Test-drive the vehicle on a level road and decelerate (with the throttle fully closed) from engine speed of 2,500 rpm to 1,000 rpm with the A/T in 2 position, or the M/T in 2nd or 3rd gear.
5. Stop the vehicle. Do not turn the ignition off.
6. Select the ALL DATA LIST in the DATA LIST MENU of the Honda PGM tester or the HDS.
7. Check the status of PULSER F/B LEARN. If it is set to NG, the enable criteria was probably not met; repeat the procedure from the beginning.

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

1. Do the ECM/PCM reset procedure.
2. Turn the ignition switch OFF.
3. Disconnect the Honda PGM tester or the HDS from the DLC.

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