A Mercedes diesel that’s down on power and stuck in limp mode with P2463, P244B, P244D or P0299 almost always points to one thing: a clogged diesel particulate filter (DPF). Here’s what those codes mean, why they happen, and how a forced DPF regeneration with the iCarsoft CR Max P clears them and restores full power.
These codes mean the DPF is overloaded with soot (P2463), its differential pressure is too high (P244B/P244D), and boost has dropped as a result (P0299), so the ECU triggers limp mode. The fix: run a forced DPF regeneration with a capable scanner such as the iCarsoft CR Max P to burn off the soot, then clear the codes. Follow up with an oil change and longer drive cycles.
- P2463 = DPF soot load too high; P244B/P244D = DPF pressure too high; P0299 = turbo underboost (knock-on effect). Together they trigger limp mode.
- A forced (service) DPF regeneration burns the soot off at ~600°C — something normal driving rarely achieves.
- The iCarsoft CR Max P walks you through DPF regen, DPF/EGR resets and 50+ service functions.
- Root cause is usually short, low-speed trips; change the oil after a regen and drive longer cycles to stop it recurring.
What P2463, P244B, P244D & P0299 mean
These four codes usually appear together on a Mercedes diesel with a blocked filter:
| Code | Meaning |
|---|---|
| P2463 | Diesel particulate filter — soot accumulation too high |
| P244B | DPF differential pressure too high (filter too restrictive) |
| P244D | DPF differential pressure — related range/performance fault |
| P0299 | Turbocharger/supercharger underboost — a knock-on effect of the choked exhaust |
In plain terms: the DPF has filled with soot, exhaust flow is restricted, boost falls, and the ECU drops the car into limp mode to protect the engine.
Symptoms you’ll notice
- Limp mode — the car won’t rev or drive normally.
- Noticeable loss of power, especially under acceleration.
- Engine management light (and often a DPF warning).
- Sometimes light blue/grey smoke — normal while a clogged DPF is clearing.
Why the DPF clogs
The car in the video is a Mercedes E-Class 1.5 diesel used mostly for short local runs (school-and-back). Diesels rely on regular longer, higher-speed drives to get hot enough for passive regeneration; constant short trips never reach that temperature, so soot builds up until the filter blocks. If your driving is mostly short-distance, a diesel may not be the best fit — a hybrid, petrol or EV suits that use better.
Watch the fix
Video credit: Mercedes Diesel P2463 P244B P244D P0299 DPF — How To Fix, by SA Diagnostic’s. Independent third-party demonstration.
Step-by-step: fix it with the iCarsoft CR Max P
The CR Max P runs the whole procedure from its Service menu. Work in a well-ventilated area with the bonnet open.
- Plug in the CR Max P, let it scan the modules, and confirm the DPF/limp-mode codes (P2463, P244B, P244D, P0299).
- Open Service → Diesel Particulate Filter and follow the prompts: switch the ignition ON, then start the engine when asked.
- The tool reads values for about 200 seconds to decide the regeneration strategy — don’t touch anything.
- The engine then revs up automatically. Exhaust temperature climbs to nearly 600°C; the whole regen takes roughly 15 minutes, ending with a cool-down phase. Watch the live data and engine temperature.
- When it finishes, go to the Engine module and read codes — they should be gone. If a component was replaced, use Reset DPF / EGR / MAF as needed (ignition ON).
- Optionally generate a report to email to the vehicle owner, then test drive to confirm full power and no limp mode.
Safety: keep the bonnet open and monitor engine temperature throughout — if you see any overheat warning on the cluster, switch the engine off immediately.
After the regen: change your oil
A forced regeneration puts a lot of heat and load on the engine and oiling system. Right after a successful DPF regen, do an oil and oil-filter change as a service — it’s cheap insurance against fuel dilution and premature wear.
When to see a professional
If a forced regeneration repeatedly fails or won’t complete, if codes return within seconds of clearing, or if there’s a real sensor/turbo fault behind P0299, the DPF may be too far gone (needing a forced clean or replacement) or another component may have failed. In those cases have a qualified technician investigate before spending on parts.
Frequently asked questions
What does P2463 mean on a Mercedes?
What do P244B, P244D and P0299 mean alongside it?
Can I clear DPF limp mode without replacing the filter?
How long does a forced DPF regeneration take?
Do I need to change the oil afterward?
Why did the DPF clog, and will it come back?
Which iCarsoft tool does this?
Disclaimer: Diagnostic and repair procedures involve heat, moving parts and exhaust gases — work in a ventilated area and follow the tool’s on-screen safety prompts. Code coverage and service functions vary by model and year; verify support for your exact vehicle. The embedded video is an independent third-party demonstration. Prices are accurate at the time of writing.
