What it means
The EVAP pressure sensor/switch C reports a circuit condition. Tank pressure plausibility for leak detection on this branch is impaired.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
EVAP pressure sensor or switch C monitors pressure in its part of the evaporative emissions system, which captures fuel vapour and checks for leaks. The control module monitors C's electrical circuit and sets P2B7A when it detects a circuit fault, making pressure information for leak detection unreliable.
Common causes
Most likely first.
- Pressure sensor C failed
- Wiring or connector fault
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
How to diagnose it
- Read freeze-frame data and related EVAP codes to see when the sensor C circuit fault occurred and whether other EVAP branches are affected.
- Inspect the fuel cap and accessible EVAP hoses near the tank and engine bay for looseness or damage, especially if there is a fuel smell.
- Locate sensor or switch C using vehicle-specific service information and inspect its connector and wiring for corrosion, damage, or poor contact.
- Check the sensor C circuit supply, ground, and signal wiring according to the manufacturer's diagram and specifications.
- If wiring and connections test correctly, test sensor C's response with a scan tool and the manufacturer's procedure before replacing it.
Common fixes
- Tighten or replace a damaged fuel cap if inspection shows it is not sealing.
- Repair damaged wiring or a poor connector connection at EVAP pressure sensor C.
- Replace EVAP pressure sensor or switch C if its circuit test confirms failure.
- Repair damaged EVAP hoses or connections found during inspection.
Can I keep driving?
You can usually drive if the vehicle runs normally, but the EVAP system may not detect leaks correctly and the check-engine light can prevent an emissions test from passing. If you smell strong fuel vapour or see a leak, stop, avoid ignition sources, and have the vehicle checked promptly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.