P245F: Diesel Particulate Filter Pressure Sensor B Circuit Range/Performance

What it means

Same as P245E with the signal in plausible range yet not matching the engine model.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

DPF pressure sensor B measures pressure at its designated points across the filter, helping the control module estimate restriction and decide when to regenerate. P245F sets when sensor B's signal is electrically plausible but does not agree with the pressure expected from engine operation, which can result from a drifting sensor, faulty hoses, or an exhaust leak.

Common causes

Most likely first.

1. Pressure sensor B drift or internal fault
2. Blocked, cracked, or leaking pressure-sensor hose
3. Exhaust leak affecting pressure readings
4. Damaged wiring or poor connector contact

Symptoms

• Check engine light or DPF warning light on
• Power loss / limp mode
• Increased fuel consumption
• Failed forced regeneration attempts

How to diagnose it

1. Record freeze-frame data and compare sensor B's pressure reading with engine speed, load, and any other DPF pressure readings.
2. Inspect sensor B's hoses for soot blockage, cracks, leaks, disconnection, or incorrect routing.
3. Check the exhaust around the pressure-sensing points for leaks that could alter the pressure reaching sensor B.
4. Inspect sensor B's connector and wiring for corrosion, poor pin contact, or damage that could make its signal inaccurate.
5. If the hoses and wiring are sound, test sensor B's response across operating conditions against the manufacturer's specification.

Common fixes

• Clear a blocked sensor B pressure hose or replace a cracked or leaking hose.
• Repair an exhaust leak affecting the pressure-sensing points.
• Restore a poor connector contact or damaged sensor B wiring.
• Replace pressure sensor B if its output remains inaccurate after hose and circuit checks.

Can I keep driving?

Drive cautiously and avoid heavy loads if a DPF warning or power reduction appears. An inaccurate sensor B reading can cause poor regeneration decisions and allow filter restriction to worsen.