CarScan
PID 7C°C

Diesel particulate filter temperature

Particulate filter temperature. It shows whether soot is being burnt off: during a regeneration it climbs to several hundred degrees and stays there for minutes. Frequent regenerations on short city trips are a common cause of oil dilution — unburnt fuel runs down into the sump. Read it next to exhaust pressure (PID 73).

What is normal

During a filter burn-off it climbs to 600 °C and above — that is normal operation, not overheating.

These figures hold for most cars, but the maker has the last word: some engines run hotter or idle higher by design.

Codes behind this reading

If the value is out of range, the unit usually says so with one of these codes.

P2002Diesel particulate filter efficiency below limit (bank 1)P0544Exhaust gas temperature sensor (bank 1) — circuit malfunction

How it feels behind the wheel

The same fault shows itself in different ways. Each sign below says what to look at in the live data.

The car has lost powerThe car moves, but sluggishly: flooring the throttle changes nothing, the revs climb reluctantly. Often the lamp is on as well.Smoke from the exhaustVisible smoke from the tailpipe. The colour is the clue: white, blue and black mean entirely different things.

How to see it

In CarScan: the Live data tab, «Start polling». The app asks the car several times per second, draws a graph and remembers the highest and lowest value of the trip.

What the app does