Vehicle
Isuzu truck NLR series, 4JJ1D engine.
Symptom
DPFE light on the dashboard, and the manual regeneration procedure could not be started from the cabin.
Procedure
We used the Bosch KTS scan tool for this truck — it supports both 12 V and 24 V systems. After selecting the truck and engine we ran fault-code tests and cleared codes, then selected DPF regeneration adaptation. The procedure can run in fast or slow mode (slow can take up to about 2.5 hours).
The KTS shows particulate filter status, engine speed, exhaust gas temperatures and differential pressure. Start the vehicle, press Go (F2), and the engine fast-idles while extra fuel is added to begin the burn-off. Exhaust fumes during this stage are normal as soot burns off.
Process time depends on how blocked the filter is. Exhaust temperatures rise and differential pressure falls; when differential pressure reaches 0.00 the burn-off is complete and cool-down begins. After both stages finish, clear remaining codes and reset “time since last regeneration” in the KTS function tests menu.
Switch off the ignition, remove the scan tool, restart — warning lights should be out. Recheck the engine oil level after regeneration — the process can dilute the oil.
Book in
Similar fault on your vehicle? Call the workshop and we will tell you what to expect for diagnosis time.