P1661
EGR Circuit Malfunction
2001-2007 Toyota Highlander 2.4L I4
Moderate SeverityPowertrain
Description
The ECM detected a fault in the EGR system control circuit.
Symptoms
- CEL
- Rough idle
- Hesitation
- Increased NOx
- Failed emissions
Common Causes
- Faulty EGR solenoid
- Carbon clogged passages
- Damaged wiring
- Vacuum leaks
Diagnostic Steps
- Test EGR solenoid
- Clean EGR passages
- Inspect wiring
- Check vacuum supply
Repair Notes
Clean or replace EGR components.
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
P1661 on Other Vehicles
Common Questions
What does code P1661 mean on a 2001-2007 Toyota Highlander?
P1661 stands for "EGR Circuit Malfunction". The ECM detected a fault in the EGR system control circuit.
What are the symptoms of P1661 on a Toyota Highlander?
Common symptoms of P1661 include: CEL, Rough idle, Hesitation, Increased NOx, Failed emissions.
What causes P1661 on a 2001-2007 Toyota Highlander?
Common causes of P1661 include: Faulty EGR solenoid, Carbon clogged passages, Damaged wiring, Vacuum leaks.