P1520: STOP LIGHT SWITCH MALFUNCTION
Short answer: P1520 means “STOP LIGHT SWITCH MALFUNCTION”. Below is what it means on each of the 2 cars we cover, with a link to the full page for each car.
P1520 on each car
| Car | Meaning on this car | Confidence |
|---|---|---|
| Toyota Vitz (1st gen) | Stop lamp switch signal | medium |
| Toyota Corolla (9th gen, E120) | STOP LIGHT SWITCH MALFUNCTION (P1520/95) | high |
Symptoms
- No stop light switch signal to ECM during driving. (2−trip detection logic)
Likely causes
- Wire harness; Stop light switch; Engine ECU
What to check, in order
- Workshop check order (RM821E): READ VALUE OF HAND−HELD TESTER -> CHECK ENGINE ECU FUNCTION -> INSPECT STOP LAMP SWITCH ASSY -> CHECK WIRE HARNESS AND CONNECTOR(Stop Lamp Switch Assy − ECU)
Causes and checks above are the general meaning. The exact test steps and values differ by car: open your car’s page.