A common thread with posts relating to DPFs is knowing when the active regeneration has commenced so that the driver can continue running the car for the 20 minutes or so duration of the process. It is often mentioned that it would be useful to have an alarm indication for this, but as yet, JLR think that this is unnecessary.

So I'd like to bounce an idea off you technical guys, that might be an inexpensive way to achieve this. I've just got myself an ELM 327 mini unit (£25, but there are cheaper ones out there) and I've purchased the Torque Pro app for my Smartphone (£2.95). Its all connected up and I'm pleased with the set up. I've now got a coolant temperature indication which is another item JLR believe we don't need. There unfortunately is no sensor pick up for the DPF temperature, but I'm wondering if the Manifold Air Pressure sensor (which CAN be read via the ELM327) would give me an indication of DPF regeneration? It normally shows 99-100kPa which is absolute pressure, i.e. ambient air pressure. Would this drop somewhat when the extra fuel was being used during DPF regeneration? There is a means of setting an alarm on the MAP indication, and this just might solve the problem.

What do you think?