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Chrysler 300/300 Touring/300C, Dodge Magnum. Manual - part 1400
Theory of Operation
The Diesel particulate filter is an inline canister filter located in the exhaust system between the engine and the
muffler. This filter captures and stores ash particles created by the diesel combustion process. This filter is moni-
tored by the ECM with a Differential Pressure Sensor. This sensor measures the difference in exhaust system pres-
sure before and after the particulate filter through tube connections directly to the exhaust pipe. As ash accumulates
in the filter, the exhaust pressure at the inlet side of the filter increases as compared to the pressure at the outlet
side of the filter. The ECM monitors the sensor to determine when to perform a particulate filter regeneration pro-
cedure which is designed to clear “burn-off” the ash collected in the filter.
•
When Monitored:
With the engine running.
•
Set Condition:
The ECM detects differential pressure that are lower than expected for certain engine operating conditions for
2.0 seconds.
Possible Causes
DAMAGED EXHAUST SYSTEM
LEAKING EXHAUST SYSTEM
HIGH RESISTANCE IN EXHAUST DIFFERENTIAL PRESSURE SENSOR CIRCUITS
HOSE/TUBE CONNECTIONS TO THE EXHAUST DIFFERENTIAL PRESSURE SENSOR
EXHAUST DIFFERENTIAL PRESSURE SENSOR
DIESEL PARTICULATE FILTER
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.
VISUAL INSPECTION
Turn the ignition off.
Visually inspect the Exhaust Differential Pressure Sensor for physical damage, proper electrical connection and
proper mechanical connection. Ensure any tubes and/or hoses connected to the sensor are in good working con-
dition and properly connected at all ends.
Visually inspect the entire exhaust system for bent, crushed or otherwise damaged tubes which may cause an
exhaust system restriction.
Inspect the exhaust system for exhaust leaks.
Were any problems found?
Yes
>> Repair or replace as necessary.
No
>> Go To 2
2.
PARTICULATE FILTER REGENERATION
Start and idle the engine.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
With the scan tool, perform the Diesel Particulate Filter Regeneration procedure.
After this procedure is complete, turn the ignition off for 60 seconds.
Test drive the vehicle.
With the scan tool, Read DTCs in the Engine Control Module (ECM).
Is the status Active for this DTC?
Yes
>> Go To 3
No
>> Test complete.
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ENGINE ELECTRICAL DIAGNOSTICS - DIESEL
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