DPF Soot Load Above Warning Threshold

Common Symptoms

• The PowerWizard 1.1 or 2.0 controller displays fault code 3719-15 on the screen
• Amber or yellow warning lamp lights up on the genset control panel
• Generator continues to run but may feel slightly less responsive under heavy load
• Exhaust may appear darker or smell more sooty than usual during extended low-load operation
• Automatic regeneration attempts may be logged in the controller history but not completing
• READY or RUN indicator stays on but a secondary alarm indicator is also illuminated
• No immediate shutdown occurs, but repeated warnings appear if the condition is not cleared

Probable Causes (Ranked by Likelihood)

• Extended operation at low load (below 30% rated output), preventing the exhaust from reaching the temperature needed for passive DPF regeneration Very Likely
• Frequent short-run exercise cycles that warm the engine but never sustain the exhaust heat required to burn off accumulated soot Very Likely
• Passive regeneration blocked by an incorrect load profile for this site, such as a standby genset that only runs weekly exercise cycles with no real load attached Likely
• DPF differential pressure sensor (soot load sensor) reading high due to a partially clogged or contaminated sensor port, triggering a false code Possible
• Upstream exhaust restriction or kinked flex section reducing exhaust flow and artificially elevating backpressure readings at the DPF Possible
• Engine running rich due to a stuck or dirty fuel injector, producing excess soot faster than the DPF can passively regenerate Less Likely
• DPF substrate approaching end of service life and physically full of ash that cannot be burned off by regeneration Less Likely

Step-by-Step Diagnostic Procedure

1. Step 1. Do NOT shut the genset down immediately. Check the PowerWizard controller display and write down the exact fault code (3719-15) and any secondary codes shown at the same time. A second code like 3719-16 (soot load critical) or 3719-0 (DPF regeneration inhibited) alongside this one means the situation is more urgent.

2. Step 2. Check your site load logs or transfer switch records. If this genset has been running at light load (less than roughly 30% of its nameplate kW rating) for most of its recent runtime, low-load operation is almost certainly the cause. A genset rated 200 kW running a 40-50 kW building load all day is a classic trigger.

3. Step 3. Inspect the exhaust stack outlet and any visible exhaust piping for black soot streaking, oily residue around joints, or obvious blockage. Do this with the genset OFF and cooled down. Heavy external soot deposits confirm the DPF has been loading up over time.

4. Step 4. Attempt an active or stationary regeneration using the PowerWizard controller menu if your unit supports it. On PowerWizard 2.0 equipped sets, navigate to: Diagnostics > Aftertreatment > Initiate Stationary Regen. The genset must be at operating temperature and the site must be clear of personnel near the exhaust outlet, which becomes extremely hot during this process. Do NOT attempt this indoors or in a partially enclosed space.

5. Step 5. If a stationary regen is not available through the controller menu, or if the controller blocks the command, you will need a technician with the Perkins EST (Electronic Service Tool) connected via the service port to initiate a forced regeneration cycle. This is the most common next step for FG Wilson packaged units.

6. Step 6. After a successful regen cycle (controller will confirm completion), clear the fault code through the PowerWizard menu under Active Faults > Clear. Run the genset at 50% or more of rated load for at least 30 minutes and monitor whether the code returns.

7. Step 7. If the code returns within a few hours of clearing, the DPF soot or ash load is beyond what regeneration can handle. At this point, the filter canister needs to be removed and sent for professional bake-and-blow ash cleaning, or replaced entirely. Call a Perkins-authorized service center or your FG Wilson dealer.

8. Step 8. As a long-term fix, review the load profile on this site. If the genset is chronically underloaded, your dealer can discuss load banking during exercise cycles or resizing the genset to better match the actual site load.

Frequently Asked Questions