DIAGNOSIS SYSTEM
Troubleshooting
| DESCRIPTION |
Engine immobiliser system data and Diagnostic Trouble Codes (DTCs) can be read through the vehicle's Data Link Connector 3 (DLC3). In some cases, a malfunction may be occurring in the immobiliser system even though the security indicator is not illuminated. When the system seems to be malfunctioning, use the intelligent tester to check for malfunctions and perform repairs.
| CHECK DLC3 |
The vehicle uses ISO 15765-4 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.
Symbols (Terminals No.)
Terminal Description
Condition
Specified Condition
SIL (7) - SG (5)
Bus "+" line
During transmission
Pulse generation
BAT (16) - Body ground
Battery positive
Always
10 to 14 V
CG (4) - Body ground
Chassis ground
Always
Below 1 Ω
SG (5) - Body ground
Signal ground
Always
Below 1 Ω
- If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.
- HINT:
- Connect the cable of the intelligent tester to the DLC3, turn the engine switch on (IG) and attempt to use the tester. If the screen displays a communication error message, there is a problem either with the vehicle or with the tester.
- If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
- If communication is still not possible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.
- If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
- If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.
| INSPECT BATTERY VOLTAGE |
Measure the battery voltage.
- Standard voltage:
- 11 to 14 V