Discovery Sport and Evoque DPF ISSUES?!

Discovery Sport and Evoque DPF ISSUES?!

For a number of years now Diesel vehicles have had a system on called DPF (Diesel Particulate Filter). This is mainly due to help with the soot build up which is inherently a problem with the diesel engine so the DPF system is designed to remove this soot as you drive by performing a “regeneration” and if all is well you will not know that the engine is doing this.

However as these vehicles age this system can sometimes break and stop working as efficiently, if the system efficiency is compromised beyond a specific limit in the ECU and is no longer working as it should you will be informed by either the EML (Engine management light) coming on or like on most modern Land Rovers you get the message displayed on the dash.

“DPF Full, Visit Dealer”

Scanning with a scan tool will more than likely list some of these faults below

• P0470 – Exhaust pressure sensor malfunction
• P0471 – Exhaust pressure sensor range/performance
• P2002 – DPF efficiency below threshold (Bank 1)
• P2003 – DPF efficiency below threshold (Bank 2)
• P2031 – Exhaust gas temperature sensor circuit (bank 1 sensor 2)
• P2032 – Exhaust gas temperature sensor circuit low (bank 1 sensor 2)
• P2033 – Exhaust gas temperature sensor circuit high (bank 1 sensor 2)
• P2034 – Exhaust gas temperature sensor circuit (bank 2 sensor 2)
• P2035 – Exhaust gas temperature sensor circuit low (bank 2 sensor 2)
• P2036 – Exhaust gas temperature sensor circuit high (bank 2 sensor 2)
• P242F – DPF restriction – Ash accumulation
• P244A – DPF differential pressure too low (Bank 1)
• P244B – DPF differential pressure too high (Bank 1)
• P2452 – DPF pressure sensor A circuit
• P2453 – DPF pressure sensor A circuit range/performance
• P2454 – DPF pressure sensor A circuit low
• P2455 – DPF pressure sensor A circuit high
• P2458 – DPF regeneration duration
• P2459 – DPF regeneration frequency

Correct Diagnoses

Keep in mind that even though some faults are stored in the ECU it doesn’t necessarily mean that by just replacing a sensor will fix it, they should be used as a guide to start your investigation only. There are instances where some tubing splits and the sensor feeds the data back to the ECU that the differential pressure is out of tolerance so the ECU assumes the DPF must be blocked.

We recently had in this 2017 Discovery Sport with the 2.0 Diesel engine in. It had the DPF message displayed on the dash saying “DPF Full Visit Dealer” after initial diagnose with our Genuine JLR Tooling and visual inspection we could see that it is in fact full and none of the sensors or piping appear to be at fault.

Unfortunately as this car had been used for many short journeys such as the school run the vehicle never had the opportunity to perform a regeneration its self and now the soot content is 42grams the ECU will not allow a forced regeneration either and recommends that the unit is replaced!

This is extremely costly option running into the £1000’s and actually is NOT required especially if its just a case of DPF being cleaned.

DPF Cleaning

It is possible to actually clean the DPF unit, there are additives that can be squirted into the exhaust system while it’s on the car but these tend to be a temporary fix as opposed to a proper “like new” repair or permanent.

The like new repair requires the entire system to be removed from the vehicle and be physically cleaned out by a specific machine under high pressure and heat.

Once strapped in the machine air flow is tested as is so this gives us an indication to how much the DPF is blocked. The machine will then raise the water pressure and temperature sharply to ensure that all soot and ash has been removed in the most efficient and safe way. After the cycle is complete it is dried out and the same air flow test is performed again this gives us a direct comparison to before and after.

It’s then refitted to the vehicle and the relevant diagnostics are carried out to inform the ECU that the unit is new.

Future use

Its important that once the freshly cleaned and tested DPF is reinstalled that the use of the vehicle is adapted to try an incorporate some motorway runs above 60mph for approx. 20mins on a regular basis. This will keep the DPF in the best possible health and prevent this issue happening again