TSX L4-2.4L (2005)
Engine Control Module: Service and Repair
ECM Reset
HDS Clear Command
The ECM/PCM stores various specific data to correct the system even when there is no electrical power such as the battery negative terminal or No. 8 FI
ECU (ECM/PCM) (15 A) fuse are disconnected. Stored data based on failed 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 this purpose. They are DTC clear, ECM/PCM reset, 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/PCM reset command erases all stored DTC codes, freeze data, readiness codes, and all specific data to correct the system except CKP pattern. If
the CKP pattern data in ECM/PCM was cleared, you must do the CKP pattern learn procedure. The CKP pattern clear command erases only CKP
pattern data. This command is for the repair of a misfire or CKP sensor.
DTC Clear
1. Do the DTC CLEAR in the CLEAR MENU with the HDS while the engine is stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON W, and wait 30 seconds.
4. Turn the ignition switch OFF, and disconnect the HDS from the DLC.
ECM/PCM Reset
This command clears stored specific data from each vehicle such as DTCs freeze data, and readiness codes. It does not clear CKP PATTERN data.
1. Do the ECM/PCM RESET in the CLEAR MENU with the HDS while the engine is stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II), and wait 30 seconds.
4. Turn the ignition switch OFF, and disconnect the HDS from the DLC.
5. Do the ECM/PCM idle learn procedure.
CKP Pattern Clear/CKP Pattern Learn Procedure
Enable Criteria
ECT at 176 °F (80 °C) or higher.
Procedure
1. Do the CKP PATTERN CLEAR in the CLEAR MENU with the HDS while the engine is stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II), and wait for 30 seconds.
4. Test-drive the vehicle on a level road: 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 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 in the CLEAR MENU with the HDS.
2. Do the ECM/PCM idle learn procedure.
3. Turn the ignition switch OFF.
4. Disconnect 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 HDS.
