What does it mean?
P1665 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: EVAP Vent Solenoid Control Circuit Malfunction .
Symptoms
- MIL on, generally with no change in how the vehicle drives
- EVAP readiness monitor never sets, so the vehicle is not ready for an emissions test
- Loud hiss when the fuel filler cap is opened, or a tank that is difficult to fill
- Occasional fuel vapour smell near the rear of the vehicle
- Related EVAP purge or leak codes stored alongside this one
Likely causes
- Vent solenoid coil open, shorted or drawing abnormal current
- Connector at the vent valve corroded; on many vehicles it hangs under the body near the fuel tank
- Underbody harness chafed on a suspension component, or damaged by road debris and rodents
- Control wire open or shorted between the solenoid and the module
- Blown fuse or lost supply voltage on the solenoid feed
- Vent valve packed with mud, dust or ice so it cannot move freely
- Failed module output driver
How to fix it
- Inspect the vent valve, its connector and the underbody harness for corrosion, mud packing and physical damage
- Command the vent valve open and closed with the scan tool and confirm it clicks and changes state
- Measure the solenoid coil resistance and compare it with the specified value
- With the ignition on, check for battery voltage at the supply side of the connector and check the related fuse
- Test the control wire back to the module for continuity and for shorts to ground and battery voltage
- Replace the vent solenoid if it is electrically faulty or mechanically jammed, and clean its mounting area
- Clear the code and complete a drive cycle to confirm the EVAP monitor runs to completion