Fixing a Stubborn DPF Fault on a Ford Transit RWD Tipper

For business enquiries email [email protected] www.orileysautos.com When a Ford Transit DPF fault keeps coming back even after new parts, something basic is being missed. In this case, a 2016 rear-wheel-drive Transit tipper came in with a history that would make most garages sigh, and I wanted to show exactly how I tracked the problem down and fixed it properly. The truck's tough history This Transit is a 2016 tipper with the 2.2 Euro 5, chain-driven engine. It does not use AdBlue. Before it came to me, another garage had already fitted: * Two new DPFs * Two new vaporizers The owner’s complaints were simple: * Fault lights return after only a few miles * "Exhaust filter at limit, drive to clean" message keeps popping up * Engine management light always on The other garage kept clearing the codes and sending him away, calling it a glitch. After a year of him going back and forth, they told him not to bring it back. Step 1: Plugging in for diagnosis I hooked up my Launch X431 Euro and ran a full system scan. Straight away I could see there was more going on than just a blocked DPF. The scan showed: 1. An ABS fault 2. Two powertrain control module faults 3. Exhaust aftertreatment glow plug circuit fault 4. P246300 DPF-related code Pressure did not look terrible, which suggested the DPF was flowing, but the figures and fault codes pointed towards a problem with the vaporizer glow plug circuit. Pinpointing the glow plug circuit problem On these, the aftertreatment glow plug sits inside the vaporizer unit. If the control unit cannot power that glow plug, you get a circuit issue and the regen will fail. What usually causes it? * Blown fuse for the vaporizer circuit * Bad wiring in the loom * Plug not fully latched in * Water ingress into the connector The fault often does not appear straight away. The van can drive 200 to 300 miles, then, when it tries a regen and energises the glow plug, it sees the fault and logs the code. Checking the fuses I pulled the fuse box cover and did a continuity check across the relevant fuses. All tested fine. . Next stop was the vaporizer itself, tucked low down on this rear-wheel-drive model. As soon as I pulled the plug off, the issue started to show. The unit fitted was a cheap vaporizer. The wiring to the connector was kinked over and the body of the unit simply was not watertight. Water had tracked down into the plug side of the connection. The insulation had obvious gaps and you could see where moisture had been getting in. So yes, the van had a “new” vaporizer, but it was a low-quality part that could not keep water out. Comparing with a genuine Ford vaporizer I laid the cheap unit next to a genuine Ford vaporizer. The difference was clear: * Genuine units have straight wiring with proper support * The connector uses decent rubber seals * No gaps in the insulation, no kinks forced into the loom Price wise, a genuine unit is around £400, whereas the cheap ones online can be £80 to £120. Fitting the fix and resetting the DPF Back in the cab, I: * Cleared the stored fault codes * Reset the DPF particle filter learned values Important warning before doing this: * Always add proper DPF cleaning fluid if you reset soot values and run a regen, otherwise you risk overheating and damaging the DPF. Forced regen and DPF clean With the new vaporizer fitted, I started a forced regen but only let it run for about five minutes. The idea was not to do a full 45-minute burn, just to wake up the system, fire the glow plug and check the circuit behaved. No new fault came back, which was a good sign. After that, we injected DPF cleaning fluid using a pressurised gun, then held the engine at about 3,000 rpm. The DPF pressure dropped from around 85 mbar down to 30 mbar, then to about 25 mbar, and after a road test it settled at 1.7 mbar. Test drive and thoughts on the aftermarket DPF I took the van out for around 10 to 12 miles, keeping an eye on: * DPF pressure * Soot loading * Exhaust temperatures Temperatures stayed under control, helped by the cleaning fluid, and the pressure figure was very low, which suggests the DPF is flowing well. My only concern is that the DPF fitted is an aftermarket unit. Some aftermarket DPFs do not hold heat properly. They can reach 500°C but struggle to get to the 600–650°C needed to burn soot effectively. When that happens, you can see fault codes saying the DPF will not reach temperature, which can send you chasing the vaporizer again even though it is fine. The van has not yet done a full self-regen with me, and that can take a long drive or even a few hundred miles of mixed use. At this point I have to let the customer use it and see how it behaves. If it later shows regen temperature issues, I will suggest a genuine DPF.