Clearing Diagnostic Trouble Codes

How to Clear the VTM-4 Control Unit Memory
There are two methods used to clear DTCs from the VTM-4 control unit memory.

The recommended method is to use the HDS with the appropriate software plugged into the data link connector (DLC).

The other method is to connect the service check signal (SCS) connector with the HDS, and manually clear the memory.

HDS method
1. With the ignition switch OFF, connect the HDS to the DLC (A).





2. Make sure the HDS communicates with the VTM-4 control unit. If it doesn't go to the DLC circuit troubleshooting.
3. Turn the ignition switch ON (II), and follow the prompts on the HDS screen to clear the DTC(s).

NOTE: See the HDS user's manual for specific instruction.

Service Check Signal Circuit (SCS) Method
1. Park the vehicle on level ground. Shift to the P position, then turn the ignition switch OFF.
2. Release the parking brake pedal.
3. With the ignition switch OFF, connect the HDS to the DLC (A).





4. Short the SCS circuit to body ground using the HDS.
5. Turn the ignition switch ON (II).
6. The VTM-4 indicator comes on and stays on for 4 seconds. Press and hold the VTM-4 LOCK switch while the VTM-4 indicator is on.
7. When the VTM-4 indicator goes off, release the VTM-4 LOCK switch.
8. The VTM-4 indicator comes on and stays on for 4 seconds. Push the VTM-4 LOCK switch while the VTM-4 indicator is on.
9. When the VTM-4 indicator goes off, release the VTM-4 LOCK switch. The VTM-4 indicator will blink twice quickly to confirm that the DTCs have been cleared from the VTM-4 control unit memory.

NOTE: If the VTM-4 indicator does not blink twice quickly, the memory has not been cleared. Turn the ignition switch OFF, then repeat steps 5 through 9.





10. Turn the ignition switch OFF, then disconnect the HDS from the DLC.