ENGINE (DIAGNOSTICS)(H4DOTC DIESEL) > DPF Warning Light > DPF WARNING LIGHT DOES NOT GO OFF

ENGINE (DIAGNOSTICS)(H4DOTC DIESEL) > DPF Warning Light

DPF WARNING LIGHT DOES NOT GO OFF

DIAGNOSIS:

Sediments exist inside DPF.

TROUBLE SYMPTOM:

DPF warning light remains ON even after approx. 2 seconds pass since ignition switch was turned to ON.

STEP	CHECK	YES	NO
1.CHECK ILLUMINATION OF MALFUNCTION INDICATOR LIGHT. Start the engine and check the malfunction indicator light.	Does the malfunction indicator light illuminate?
2.CHECK DTC.	Is DTC displayed?	Check the appropriate DTC using the “List of Diagnostic Trouble Code (DTC)”. After the operation is complete, perform the following operations, and go to the next step. • Catalytic converter & DPF replacement • DPF maintenance (DPF change) • Check the DPF pressure difference sensor pipe. • Check the exhaust temperature sensor 1 and exhaust temperature sensor 2 circuit.	Check the malfunction indicator light circuit. After the operation is complete, go to the next step.
3.CHECK DTC.	Is DTC displayed?	Check the appropriate DTC using the “List of Diagnostic Trouble Code (DTC)”. After the operation is complete, go to the next step.
4.CHECK DPF WARNING LIGHT ILLUMINATION HISTORY.	Has the DPF warning light illuminated before?		Perform the following operations, and go to the next step. • DPF maintenance (DPF regeneration) • Check the DPF pressure difference sensor pipe. • Check the exhaust temperature sensor 1 and exhaust temperature sensor 2 circuit.
5.CHECK USAGE CONDITION. Ask the customer whether the vehicle was driven under the conditions described in the owner's manual after the DPF warning light was illuminated.	Was the vehicle driven under the conditions described in the owner's manual?		Perform the following operations, and go to the next step. • DPF maintenance (DPF regeneration) • Inspection using “General Diagnostic Table”. • Check the DPF pressure difference sensor pipe. • Check the exhaust temperature sensor 1 and exhaust temperature sensor 2 circuit.
6.CHECK EXHAUST GAS. 1) Start the engine and warm up engine until coolant temperature is higher than 75°C (167°F). NOTE: For detailed operation procedures, refer to “READ CURRENT DATA FOR ENGINE”. 2) Race the engine several times so that the engine speed exceeds 3,000 rpm, and check the exhaust gas while racing the engine.	Is black smoke emitted?	Perform the following operations, and go to the next step. • Catalytic converter & DPF replacement • DPF maintenance (DPF change) • Check the DPF pressure difference sensor pipe. • Check the exhaust temperature sensor 1 and exhaust temperature sensor 2 circuit.
7.CHECK USAGE CONDITION. Ask the customer about the following conditions. • Driving is often ended before the warming-up of the engine is complete. • Intensive acceleration is sometimes performed before the warming-up of the engine is complete. • The vehicle is frequently driven in the low speed range, including when caught in a traffic congestion.	Is any condition relevant?	Explain to the customer about the following. • The DPF warning light may illuminate under these usage conditions. • If the DPF warning light illuminates, the vehicle must be driven under the conditions described in the owner's manual.	End.
8.CHECK CURRENT DATA. Read the data of “catalyst temperature #11” and “catalyst temperature #12” when idling the engine, using the Subaru Select Monitor. NOTE: For detailed operation procedures, refer to “READ CURRENT DATA FOR ENGINE”.	Are the data of “catalyst temperature #11” and “catalyst temperature #12” 10°C (50°F) or more?		Check the exhaust temperature sensor 1 and exhaust temperature sensor 2 circuit.
9.CHECK AIR INTAKE SYSTEM. Check the air intake system. NOTE: Check the following items. • Clog or heavy dirt on the air cleaner element • Installation condition of each part of the air intake system • Damage of each part of the air intake system (cracks, holes, etc.)	Is there any fault in air intake system?	Repair or replace faulty parts.
10.CHECK BOOST CONTROL VALVE. Check the boost control valve.	Is there any fault in the boost control valve?	Replace the boost control valve.
11.CHECK FUEL USED.	Is properly-specified fuel used?		Change the fuel to properly-specified fuel.
12.CHECK ACCELERATION PERFORMANCE.	Does poor acceleration, or engine stalls, hesitation, or sputters at acceleration occur?	Inspection using “General Diagnostic Table”.
13.CHECK SERVICE HISTORY.	Has the vehicle been repaired for the same problem before?	Replace the DPF pressure difference sensor.
14.CHECK USAGE CONDITION. Ask the customer about the following conditions. • Driving is often ended before the warming-up of the engine is complete. • Intensive acceleration is sometimes performed before the warming-up of the engine is complete. • The vehicle is frequently driven in the low speed range, including when caught in a traffic congestion.	Is any condition relevant?	Explain to the customer about the following. • The DPF warning light may illuminate under these usage conditions. • If the DPF warning light illuminates, the vehicle must be driven under the conditions described in the owner's manual.	Perform the following operations. • Catalytic converter & DPF replacement • DPF maintenance (DPF change)