P244B: Diesel Particulate Filter Differential Pressure Too High Bank 1

What it means

The measured differential pressure across the particulate filter is higher than the calibrated limit on Bank 1. The code identifies excessive pressure, not a pressure-sensor offset.

At a glance

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

How it works

A differential-pressure sensor measures the pressure drop across the Bank 1 diesel particulate filter (DPF), which the engine control module uses to assess exhaust restriction and filter loading. P244B sets when that measured pressure difference is higher than the calibrated limit. A soot- or ash-restricted filter, a problem with the sensing hoses or sensor circuit, or another exhaust issue can produce the high reading.

Common causes

Most likely first.

1. DPF soot or ash buildup restricting flow
2. Pressure-sensor hoses blocked, leaking, or damaged
3. Faulty differential-pressure sensor or wiring
4. Exhaust restriction or leak affecting pressure readings

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. Review freeze-frame data and live differential-pressure readings across engine loads, and check for related DPF, sensor, or exhaust codes.
2. Inspect both Bank 1 pressure-sensor hoses for blockage, leaks, kinks, damage, or incorrect connection, since these can skew the measured pressure difference.
3. Check the sensor ports and wiring connectors for soot, corrosion, loose connections, or heat damage.
4. Compare the differential-pressure sensor readings at rest and with the engine running against the manufacturer’s specification to assess sensor and circuit operation.
5. If the hoses, sensor, and circuit are plausible, assess DPF soot or ash loading and check for exhaust restrictions or leaks affecting the measurement.

Common fixes

• Clear a blocked pressure hose or sensor port.
• Replace leaking, kinked, or damaged pressure-sensor hoses.
• Repair damaged wiring or replace a faulty differential-pressure sensor if confirmed by testing.
• Service or replace a soot- or ash-restricted Bank 1 DPF according to the manufacturer’s procedure.
• Repair an exhaust restriction or leak affecting the pressure measurement.

Can I keep driving?

If power is reduced or limp mode occurs, avoid towing and hard acceleration and arrange diagnosis soon. Continuing to drive with a restricted DPF can worsen power loss and fuel consumption.