New Thar suddenly throws DPF warning on highway; drops speed to 40 km/h

They replaced the EGR with one from a new test drive Scorpio-N as both SUVs have the same engine.

Rajiv drops in a query via this Team-BHP share page.

I own a Mahindra Thar automatic Diesel 4x4 HT. It has covered over 3,000 km. I was driving on the expressway with cruise control engaged at 120 km/h. After driving for 500 km, I saw a warning in the instrument cluster saying "DPF clogged ".

As usual, I contacted the dealer. He advised me to check if there is an option to regen. I checked it was not there. He suggested I drive 70 km to a nearby service station as there was no problem in driving the vehicle. So, I followed the instructions. After 30 km, I felt the speed drop suddenly. At the same time, I informed the dealer, who told me to drive the car at 60 km/h for 30 minutes and the problem would be solved.

But after all this, I found that the Thar couldn't even go beyond 40 km/hr and the worst thing was that it was 9 pm and there was nothing in a 70 km circumference on the expressway. After 70 km we could see Agra, but the Thar’s condition was not good as speed was not increasing. Now, the dealer was also unable to help. I called the 24x7 helpline. They arranged a technician online, but it was of no use. Then I requested towing as it was in the policy.

I kept driving towards Agra. The towing person was asking for my location. By the time he reached me, I touched Agra doing speeds of 20 - 40 km/h.

I stayed at a hotel as it was night. In the morning went to the service station at Agra and described the problem. They started troubleshooting, checked and did regen. After this, they tested again and found out that there was some problem in the system. The total soot collection was increasing as per the technician which could lead to the same problem again. There was another problem showing on the computer.

Here is a picture of the computer screen: "HFM SENSOR SIGNAL PLAUSIBILITY- LOW SENSITIVITY DRIFT- ERROR STATUS- PENDING "

As per the service person, they need to remove this pending status. For that, they started diagnosis with all the sensors and removed the errors one by one. They also replaced one sensor with one from a new Thar, but the problem still remained.

Now they told me that they need to contact the Manufacturer / OEM. I told them to do whatever was required. They got advice from the manufacturer to check the EGR.

They replaced the EGR with one from a new test drive Scorpio-N as both vehicles have the same engine. After this, they tested and found that the vehicle was good and not generating excess soot.

I drove back and completed my trip in a thrilling manner with extra pressure on myself.

Till now there has been no problem, but I am surprised how it happened. Can anybody explain what was wrong?

Here's what BHPian Jaggu had to say on the matter:

I think it was just a faulty exhaust gas recirculation unit. These BS6 diesel engines are becoming really a pain to live with, wonder why none of the manufacturers are able to crack the issue properly?

Check out BHPian comments for more insights and information.