Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Toyota Matrix Base, 4WDFACTORY OEM SERVICE PROCEDURE
Data Link Connector No. 3 Inspection
NOTE:
The vehicle's ECM uses ISO 9141-2 for communication. Terminal arrangement of DLC3 complies with SAE J1962 and matches ISO 9141-2 format.
- If your display shows UNABLE TO CONNECT TO VEHICLE when you have connected cable of OBD II scan tool or hand-held tester to DLC3, turned ignition switch ON and operated scan tool, there s a problem on vehicle side or tool side. If communication is normal when tool is connected to another vehicle, inspect DLC3 on original vehicle. Go to next step. If communication is still impossible when tool is connected to another vehicle, problem is probably in tool itself, so consult service department listed in tool's instruction manual.
- Check DLC3 for loose or damaged terminals. See Fig 1. Ensure DLC3 terminals are in correct position in connector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary. If connector and terminals are OK, go to next step.
- Check voltage and resistance between ground and specified terminal on DLC3. See DLC3 VOLTAGE & RESISTANCE SPECIFICATIONSΒ table. If voltage and resistance readings are not as specified, check wiring circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
DLC3 VOLTAGE & RESISTANCE SPECIFICATIONS
| Terminal No. (Circuit) | Voltage Or Resistance | Condition |
|---|---|---|
| 4 (Chassis Ground) - Body Ground | Less Than 1 Ξ© | Always |
| 5 (Signal Ground) - Body Ground | Less Than 1 Ξ© | Always |
| 7 (BUS Communication) | Pulse Generation | During Transmission |
| 16 (Battery Voltage) - Body Ground | 9-14 V | Always |
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
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