What does it mean?
P1485 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: EGR Solenoid Valve (Vacuum) Circuit Malfunction .
Symptoms
- MIL on
- Rough idle or stumbling if EGR flow is stuck open
- Pinging and knock under load if EGR never flows
- Slight loss of power and higher fuel consumption
- Hesitation during light acceleration
- Emissions test failure with high oxides of nitrogen
Likely causes
- Open or shorted control circuit to the EGR vacuum solenoid
- Failed solenoid coil, open or shorted internally
- Connector at the solenoid corroded or heat damaged from its underhood location
- Blown fuse or lost ignition feed to the solenoid
- Harness chafed against the intake manifold or a mounting bracket
- Carbon and debris jamming the solenoid ports, which raises current draw
- Module output driver failure
How to fix it
- Check which other EGR codes are stored to separate an electrical fault from a flow fault
- Inspect the solenoid connector and wiring for heat damage, melted pins and corrosion
- Verify ignition voltage at the solenoid feed with the key on
- Measure the solenoid coil resistance and compare it with specification
- Command the solenoid with a scan tool and confirm it clicks and passes vacuum
- Inspect the vacuum hoses to the EGR valve for cracks, softening and blockage
- Replace the solenoid if it fails its electrical or flow test, then clear codes and retest under load