GS400 OBD II scan tool Operating Instructions

CAUTION: Don’t connect or disconnect any test equipment with ignition on or engine running.
HOT KEY: Pressing the READ button will allow you to quickly retrieve and read the DTCs without going through the menu mode.

1) Turn the ignition off.
2) Locate the vehicle’s 16-pin Data Link Connector (DLC).
3) Plug into the GS 400 scan tool cable connector to the vehicle’s DLC.
4) Turn the ignition on. But do not start the engine.
5) Turn the GS 400 scan tool’s power on.
6) Press the Y button. A sequence of messages showing the OBD2 protocols will be observed on the display until the vehicle protocol is detected.

If the GS400 scan tool fails to communicate with the vehicle’s ECU (Engine Control Unit), a “LINKING ERROR!” message shows up on the display.
Verify that the ignition is ON;
Check if the GS400 scan tool’s OBD II connector is securely connected to the vehicle’s DLC;
Verify that the vehicle is OBD2 compliant;
Turn the ignition off and wait for about 10 seconds. Turn the ignition back to on and repeat the procedure from step 6.

If the “LINKING ERROR” message does not go away, then there might be problems for the scan tool to communicate with the vehicle. Contact your local distributor or the manufacturer’s customer service department for assistance.

7) After a test result summary is displayed (MIL status, DTC counts, I/M Status and Freeze Frame Data), press any key for the Vehicle Diagnosis menu to come up.
8) Use the UP/DOWN scroll buttons to select Trouble Codes from the menu and press the Y button.

Vehicle Diagnosis
1) Trouble Codes
2) Erase Codes
3) Freeze Frame
4) I/M Status
5) Vehicle Infor.
6) Save Scan Results

If there are no Diagnostic Trouble Codes present, the display will indicate “NO CODES ARE FOUND!”
If there are any Diagnostic Trouble Codes present, a brief overview with the total count of the Trouble Codes, followed by that of the
Fault Codes and Pending Codes will be reported on the display.

Trouble Codes
Codes Total: 06
Fault Codes: 04
Pend Codes: 02
Press [Y] to select
vehicle manufacturer

9) If the retrieved DTCs do not contain any manufacturer specific codes (all generic), view the DTCs by pressing the Y button.
● The DTC number and its definition will show on the LCD display.
● The sequence of the DTC currently being observed, the total number of codes detected and type of code (Generic or Manufacturer specific) will be observed on the upper right hand corner of the display.
If the code being displayed is a pending code, the Pd icon will be observed on the upper right hand corner of the display too.
● When a DTC’s definition covers more than one display screen, use the Y button, as necessary, to view any additional information.

10) If the retrieved DTCs contain any manufacturer specific or enhanced codes, you will be prompted to select the vehicle manufacturer to view the DTC definitions. Use the UP/DOWN scroll buttons to select the right manufacturer and then press the Y Button to view the DTC definitions.
If the manufacturer for your vehicle is not listed, use the UP/DOWN scroll buttons to select Other and press the Y button.
If the DTC definition is not available (mostly for manufacturer specific codes), a message will be observed on the display.

11) If more than one DTC is found, use the UP/DOWN scroll buttons, as necessary, until all the GS 400 code reader codes have been shown up.