| LED | Indication | |-----|-------------| | | +12V on pin 16 present. | | GND (green) | Good connection to pin 4/5. | | CAN (yellow) | Flickers during CAN traffic. | | K-LINE (yellow) | Flickers during K-Line activity. | | SHORT (red) | Voltage >7V on pin 5 (bad ground) or short detected. |
| Symptom | Likely Cause | Action | |---------|--------------|--------| | No power LED | Blown OBD fuse (often F16/F17 in BSI) | Check fuse, repair short | | CAN High = 12V | Short to battery | Trace wiring, replace damaged harness | | CAN Low = 0V | Short to ground | Inspect for chafing near engine/steering | | CAN diff = 0V, both 2.5V | No active communication | Check ECU power/ground, try another ECU | | K-Line idle 0V | Open circuit | Check pin 7 continuity to ECU | | Intermittent connection | Loose terminal in OBD socket | Retension pins, clean with contact cleaner | psa interface checker
: Used in specific communication architectures. How to Use the PSA Interface Checker | LED | Indication | |-----|-------------| | |
: Ensure you have a stable Windows PC, preferably running a 32-bit version for older Lexia software or Windows 10/11 for modern Diagbox versions. | | K-LINE (yellow) | Flickers during K-Line activity