P243B: Particulate Filter Restriction Forced Limited Power Bank 2

What it means

Particulate Filter Restriction Forced Limited Power Bank 2: the control module has detected this fault condition.

At a glance

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

How it works

The DPF on bank 2 traps soot, and pressure readings across the filter help the control module judge exhaust restriction. This code indicates that restriction has reached a forced limited-power condition, which may result from soot or ash buildup or from a misleading pressure-sensor signal.

Common causes

Most likely first.

1. DPF soot or ash buildup causing severe restriction
2. Failed or repeatedly interrupted regenerations
3. Faulty DPF pressure sensor or damaged pressure-sensor hoses

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. Use a scan tool to record freeze-frame data, bank 2 DPF differential pressure, soot estimate, and any forced-regeneration or limited-power status.
2. Inspect the bank 2 pressure-sensor hoses for splits, blockage, heat damage, or loose connections before treating a high pressure reading as a failed filter.
3. Check bank 2 exhaust temperature sensor readings and wiring for implausible values that could prevent or mismanage regeneration.
4. Look for related engine or fuel-system faults that could create excess soot, and review whether recent regeneration attempts were interrupted.
5. Compare pressure readings and sensor operation with the manufacturer's specification; if restriction is confirmed, follow the vehicle's service procedure to assess the filter and safe regeneration eligibility.

Common fixes

• Repair blocked, split, or heat-damaged bank 2 DPF pressure-sensor hoses.
• Repair faulty pressure or exhaust temperature sensor wiring, or replace a sensor confirmed out of specification.
• Correct engine or fuel-system faults producing excess soot.
• Have the bank 2 DPF cleaned or replaced if testing confirms severe restriction.

Can I keep driving?

Because this condition can trigger limited power, avoid fast roads, towing, and situations where sudden loss of acceleration would be hazardous; arrange prompt diagnosis. Do not attempt repeated forced regenerations without confirming that the filter and sensors can safely support them.