P2B7C: EVAP System Pressure Sensor/Switch C Circuit Low

The EVAP pressure sensor/switch C reports a circuit low condition. Tank pressure plausibility for leak detection on this branch is impaired.

Low severity. Can I keep driving?Yes, you can normally keep driving. If there is a strong smell of gasoline, find the leak before continuing and do not smoke nearby.

Symptoms

Check engine light on
Possible smell of fuel near tank or engine bay
Failed emissions inspection
Loose-cap warning may appear

Most likely causes

Signal wire shorted to ground
Internal sensor short
Connector pins corroded - high contact resistance

What to check, in order

Start with the simplest. You can tick off each step.

Start with the fuel cap: tighten it fully and check its seal
With the connector unplugged, check whether the signal wire is making contact with ground.
Inspect the hoses and connections around the tank and the charcoal canister
Use the scanner to test the purge and vent solenoid valves
Run a smoke test to find small leaks

Good to know

Repair difficulty: easy
It affects emissions.

What each character of P2B7C means

P: Powertrain: engine and transmission
2: Generic code: same on every make
B: Subsystem depends on the code range
7C: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2B7C?

Yes, you can normally keep driving. If there is a strong smell of gasoline, find the leak before continuing and do not smoke nearby.

What causes code P2B7C?

The most common causes are: signal wire shorted to ground; internal sensor short; connector pins corroded - high contact resistance.

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.