Faulty Diesel Particulate Filter (DPF) in VW Tiguan: How to Diagnose and Fix

Diesel engines need a Diesel Particulate Filter (DPF) to minimise harmful emissions. But what happens when it stops working as it should? This blog post will address this question and we’ll talk you through how we helped a customer of ours with this exact problem.

When a client noticed the engine warning light on their VW Tiguan, they wisely decided to bring their VW to our garage in Shaftesbury. Although there were no visible problems, they were still worried that this could be a serious issue with their vehicle.

The engine management light serves as an early warning system that indicates when there is a problem with your vehicle. It’s best not to ignore these warnings as they could escalate and lead to costly repairs. Nobody wants that, right? So, our VW specialists were on hand to help with this very problem.

Let’s get into it!

What We Found

After examining the Tiguan, our VW expert verified that the engine management light illuminated as soon as the engine was started. To identify the root cause of the issue, our mechanic conducted a diagnostic test, which produced the following error code:

P154B 00 – Diesel Particulate Filter, difference pressure sensor faulty. 

For our specialists, fault codes are like road signs, leading us to where they should go to fix the problem.

This was an issue with the DPF, so it was important to resolve it quickly before it worsened. 

Failure of a DPF can cause a variety of problems, including:

• Black smoke coming from your exhaust
• Failing your MOT emissions test
• Mechanical failure
• Your VW could enter into “limp mode” to protect the engine from damage. 

You shouldn’t ignore any DPF issues as they may lead to more costly repairs further down the line.

Several problems can cause DPF issues. However, on this occasion, we turned to the VW technical information – the detailed specifications, instructions, and guidelines provided by Volkswagen to assist mechanics – to find the root cause. We have access to the same VW technical information as Volkswagen dealerships at DCM Autocentre. Our garage in Shaftesbury offers dealership-level service and great value compared to the VW dealership.

How We Diagnosed the Problem

Our VW expert ran a series of live data checks and found the pressure sensor on the DPF had “implausible readings”.

We use a 15-step diagnostic process at DCM Autocentre to fix any problem on the first visit. As a result, you save time, stress, and value compared to taking your vehicle to the local VW dealership. By using the VW technical information (including the technical bulletins), our VW specialist identified a common issue with the DPF sensor. 

Our VW experts are very thorough during their diagnosis, so ensured it was not a wiring problem by testing the voltage of the wiring using an Oscilloscope (the main VW dealer wouldn’t do this!)

The results showed that all wires were working properly, which proved the DPF sensor was at fault.

How We Fixed the VW Tiguan

Once our VW expert had identified the cause of the illuminated engine management light, we discussed the issue with the client and offered recommendations. At DCM Autocentre, you are always in control. Only once we have your approval to proceed will we begin fixing your vehicle. 

After all parties had agreed to our recommendations, we sourced a replacement DPF sensor to complete the fix. Our VW expert technicians only use genuine Volkswagen parts or high quality equivalents to ensure your vehicle performs at its very best. 

Our expert conducted a live data road test after replacing the faulty sensor to ensure the DPF was now fully functioning. Our extensive road testing confirmed that the Tiguan’s DPF was working correctly again, and the engine management light was no longer illuminated! 

Our client was thrilled to have their vehicle back in perfect working order. In addition to keeping them updated throughout the process, we provided  better value than the VW dealer.

What more could you ask for?

In Summary

Upon noticing that their VW Tiguan’s engine management fault light was lit up, a recent client of ours brought their  VW Tiguan to DCM Autocentre as soon as they could. After thoroughly testing the vehicle with VW technical information and our 15-step diagnostic process, we found fault with the DPF sensor. 

Since the VW didn’t show any performance drop when the problem was detected, we were fortunate to catch the problem early. We then had our VW specialist replace the DPF sensor with a high-quality VW replacement part. 

After a thorough road test, the client received their keys and left with a smile knowing their car was back in top condition.

Do you have an illuminated engine management light on your VW? The problem will only get worse if you ignore it. Call DCM Autocentre today if you need quality VW repairs. 

Contact us today to schedule your VW check-up.

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