P1790 (blink 65, U441E) on Toyota Corolla E120: ST SOLENOID VALVE MALFUNCTION
Short answer: P1790 means “ST SOLENOID VALVE MALFUNCTION”. The car’s computer has found a fault in the ECT U441E system. First check: workshop check order (RM821E): INSPECT TRANSMISSION WIRE(ST) -> CHECK WIRE HARNESS AND CONNECTOR(Transmission wire − ECU) -> INSPECT SOLENOID ASSY, TRANSMISSION(ST).
- Code
- P1790 · blink 65
- System
- ECT U441E
- Dashboard light
- CHECK ENGINE (MIL) does NOT light (DTC stored in memory only)
- Applies to
- 4-speed A/T U441E. Not a PK fitment (the PK EPC lists only A246E and U340E). Other-market fitment unverified.
- Confidence
- high (official Toyota RM821E)
- Source
- toyotamanuals.gitlab.io
Symptoms and when it is set
- ECU memorizes DTC P1790/65 if (a) or (b) condition below is detected once or more, but ECU does not start O/D OFF indi- cator light blinking. (a) Solenoid resistance is 30 W or lower (short circuit) when solenoid energized. (b) Solenoid resistance is 100 kW or higher (open circuit) when solenoid is not energized.
Likely causes
- Transmission wire; Wire harness; ST solenoid valve; Engine ECU
What to check, in order
- Workshop check order (RM821E): INSPECT TRANSMISSION WIRE(ST) -> CHECK WIRE HARNESS AND CONNECTOR(Transmission wire − ECU) -> INSPECT SOLENOID ASSY, TRANSMISSION(ST)
Related on this car
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.