DPF Regeneration Conditions Not Met
The P246B code indicates that the engine control module (ECM) has detected that the vehicle is not operating under the correct conditions to perform a diesel particulate filter (DPF) regeneration. This typically occurs when the vehicle is driven at low speeds, short distances, or with excessive idling, preventing the exhaust temperature from reaching the required level to burn off soot. The DPF can become clogged, leading to reduced performance and potential damage if not addressed.
01. Most Common Causes
- Frequent short trips or low-speed driving
- Faulty exhaust gas temperature sensor
- Malfunctioning DPF pressure sensor
- Excessive idling
- Engine coolant temperature too low
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Increased fuel consumption
- Black smoke from exhaust
- Regeneration cycle not initiating
03. Step-by-Step Diagnosis
Step 1: Scan for codes and check freeze frame data to confirm P246B.
Step 2: Inspect exhaust gas temperature sensors and DPF pressure sensor for proper operation.
Step 3: Verify vehicle driving history; advise customer on proper regeneration conditions.
Step 4: Perform forced regeneration using a scan tool if sensors are okay and conditions are met.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
You can drive short distances, but avoid extended driving as the DPF may clog further, leading to costly repairs. It's best to address the issue promptly.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. If sensors need replacement, costs can range from $200-$600. Forced regeneration may be included in diagnostic fees.