P200C: Particulate Filter Over Temperature (Bank 1)

What it means

The control module has detected particulate filter overtemperature on bank 1. The code does not establish that a runaway regeneration caused it.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The particulate filter in the exhaust on bank 1 traps soot, and regeneration burns accumulated soot away. The control module monitors filter temperature using exhaust temperature data and sets P200C when the bank 1 filter temperature is detected above its permitted range. The code does not by itself prove that regeneration ran away; a sensor fault or an engine or regeneration problem may also be involved.

Common causes

Most likely first.

1. Excessive soot load triggers runaway regeneration
2. Post-injection over-fueling during regeneration
3. DPF temperature sensor reading drifts high

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, DPF warnings, and live bank 1 exhaust temperature readings to establish when the overtemperature was recorded and whether readings look plausible.
2. Inspect the bank 1 temperature sensor wiring and connector, along with exhaust components, for damage, loose connections, or signs of overheating.
3. Check available soot-load, differential-pressure, and regeneration status data to assess restriction and whether regeneration is being commanded or repeatedly failing.
4. Investigate engine faults that can add soot or fuel during regeneration, including relevant injection, air, and misfire codes, before attempting regeneration.
5. Test the bank 1 temperature sensor and its circuit against the manufacturer's procedure; do not force regeneration until the overtemperature cause is understood.

Common fixes

• Repair damaged bank 1 exhaust temperature sensor wiring or connector.
• Replace a bank 1 exhaust temperature sensor that fails testing or reports implausible temperature.
• Correct the engine or regeneration fault causing excessive soot or fuel dosing.
• Clean or replace the particulate filter if testing confirms it is restricted or damaged.

Can I keep driving?

With a DPF warning, power loss, or limp mode, avoid continued driving and stop safely if there are signs of extreme exhaust heat, smoke, or burning; do not attempt a forced regeneration. Continued operation can damage the filter or nearby exhaust parts, so get the overtemperature cause assessed promptly.