If you’re driving or working on a newer model Volkswagen Crafter (manufactured in 2024, engine code DMZB), you might run into a frustrating issue where the check engine light pops on seemingly out of nowhere. It’s becoming a really common fault on these newer models.

Symptoms of the Fault

The main sign of this problem is the check engine light coming on your dashboard. Most of the time, the vehicle drives completely normally. You won't feel any loss of power and the engine runs smooth after it starts. While it is possible that the engine might struggle a little to start in very cold weather, this is actually rare. Usually, the vehicle starts fine and it is just the warning light that lets you know something is wrong.

If you scan the vehicle with a diagnostic tool, you will likely see one (or a combination) of the following fault codes.

  • P064C00: Glow plug control unit

  • P067100: Glow plug cylinder 1 electrical circuit fault

  • P067200: Glow plug cylinder 2 electrical circuit fault

  • P067400: Glow plug cylinder 4 electrical circuit fault

The core of this problem lies in the physical design of the glow plug connectors.The glow plug connectors use a rubber seal to hold onto the engine cylinder head. On the original parts, this rubber seal starts to loosen up after a while. When the seal loses its grip, the connector disconnects from the glow plug. This breaks the electrical circuit and triggers the fault code. Fixing this issue involves reseating the connectors with the updated seals.

                                                                  Faulty Connector seal

Volkswagen has designed a new seal to fix this.As shown in the comparison below, the new design has an improved shape to ensure a much tighter grip on the cylinder head, preventing the connector from vibrating loose.

                                                                   Old seal and new seal

If the problem is on Cylinder 1, you might be able to see the disconnected connector without taking anything apart. However, Cylinder 1 is usually the easiest to reach. To check all of them properly, you will need to move some parts out of the way.

You may have noticed that the fault codes listed above only cover Cylinders 1, 2, and 4. That's because the glow plug on Cylinder 3 has a built-in combustion chamber pressure sensor. Because of that sensor, the connector is totally different from the other three standard plugs and doesn't suffer from the same loose rubber seal issue.

The Repair Process

The difficulty and time needed for this repair depend on how the engine is arranged in your vehicle. 

Transverse engines are a bit easier to work on because they have more space than longitudinal engines. For transverse engines, the job is a little annoying but manageable. You do not need to take the intercooler completely out of the vehicle. You can just loosen the bolts and move the intercooler to the side with the coolant pipes still connected. This allows you to complete the work without draining the coolant.

 

                                                              Transverse Engine

Longitudinal engines are tighter and require more work. For these engines, it is much easier if you take the whole cooler completely away. Once you have removed the intercooler, you then have to remove the intercooler bracket. After that bracket is gone, you will finally have clear access to the glow plugs. Once you have access, you simply swap the old seals for the new ones and push the connectors back on tightly.