P1656 (blink 39, 3ZZ) on Toyota Corolla E120: OCV CIRCUIT MALFUNCTION
Short answer: P1656 means “OCV CIRCUIT MALFUNCTION”. The car’s computer has found a fault in the EFI 3ZZ-FE system and turns on the Malfunction indicator lamp (Check Engine). First check: workshop check order (RM821E): INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSY -> INSPECT ECU -> CHECK HARNESS AND CONNECTOR(ENGINE ECU−OCV).
- Code
- P1656 · blink 39
- System
- EFI 3ZZ-FE
- Dashboard light
- Malfunction indicator lamp (Check Engine)
- Applies to
- 3ZZ-FE 1.6 (PK SE Saloon 1.6 2002-05 ZZE121)
- Confidence
- high (official Toyota RM821E)
- Source
- toyotamanuals.gitlab.io
Symptoms and when it is set
- Open or short in oil control valve circuit
Likely causes
- Open or short in oil control valve circuit; Oil control valve; Engine ECU
What to check, in order
- Workshop check order (RM821E): INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSY -> INSPECT ECU -> CHECK HARNESS AND CONNECTOR(ENGINE ECU−OCV)
Related on this car
Same code on other cars
Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.

