What does it mean?
P1425 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Tank Ventilation Valve Short to Ground .
Symptoms
- MIL on, usually with EVAP related codes stored together
- Valve stuck open, drawing fuel vapour into the intake at idle and causing a rich condition
- Rough or unstable idle, sometimes stalling shortly after refuelling
- Difficulty starting immediately after filling the tank
- Fuel smell around the vehicle and possible emissions test failure
Likely causes
- Control wire chafed to ground where the harness passes the intake manifold or a bracket
- Internally shorted solenoid winding in the tank ventilation valve
- Water and corrosion inside the valve connector creating a leakage path
- Crushed or pinched harness section after intake work or a previous repair
- Rodent damage to the wiring near the valve, which often sits in an exposed location
- Corroded terminals causing the control pin to contact the shell or a ground pin
- PCM low side driver internally shorted, considered only after circuit tests are clean
How to fix it
- Unplug the valve and measure resistance from the control terminal to ground; a very low value confirms the short
- Repeat the test with the PCM connector disconnected to separate a harness fault from a module fault
- Measure the solenoid winding resistance and check for continuity between the winding and the valve body
- Inspect the connector for moisture, corrosion and terminal damage, and clean or replace it as needed
- Follow the harness route and look for chafing near the intake, brackets and heat sources
- Repair the shorted wire and secure it clear of sharp or hot surfaces
- Replace the tank ventilation valve if internally shorted, then command it with a scan tool and confirm it holds vacuum when closed