Chrysler 300/300 Touring/300C, Dodge Magnum. Manual — part 1444

For a complete wiring diagram Refer to Section 8W

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 or “burn-off” the ash collected in the filter.

•

When Monitored:
With the ignition on.

•

Set Condition:
The (K355) Exhaust Differential Pressure Sensor signal is above 4.96 volts for 2.0 seconds.

Possible Causes

INTERMITTENT DTC

(K354) EXHAUST DIFFERENTIAL PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE

(K355) EXHAUST DIFFERENTIAL PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE

(K951) EXHAUST DIFFERENTIAL PRESSURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE

(K355) EXHAUST DIFFERENTIAL PRESSURE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

(K951) EXHAUST DIFFERENTIAL PRESSURE SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

EXHAUST DIFFERENTIAL PRESSURE SENSOR

ENGINE CONTROL MODULE (ECM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)

Diagnostic Test

1.

DTC IS ACTIVE

Ignition on, engine not running.

With the scan tool, Clear DTCs in the Engine Control Module (ECM).

Monitor the scan tool for at least two minutes.

Cycle the ignition key off and on several times, leaving the ignition on for at least 10 seconds at a time.

Start the engine.

Allow the engine to reach normal operating temperature.

With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

>> Go To 2

No

>> Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE -

DIAGNOSIS AND TESTING)

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2.

(K354) EXHAUST DIFFERENTIAL PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO
VOLTAGE

Turn the ignition off.

Disconnect the Exhaust Differential Pressure Sensor connector.

Disconnect the Engine Control Module (ECM) connector.

Remove the ASD Relay.

Connect a jumper wire between cavity 30 and cavity 87 of the ASD
Relay Connector.

Turn the ignition on.

Measure the voltage of the (K354) Exhaust Differential Pressure Sensor
5 Volt Supply circuit in the Exhaust Differential Pressure Sensor har-
ness connector.

Is there any voltage present?

Yes

>> Repair the (K354) Exhaust Differential Pressure Sensor 5

Volt Supply circuit for a short to voltage.

Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

No

>> Go to 3

3.

(K355) EXHAUST DIFFERENTIAL PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE

NOTE: The jumper wire should still be in place.
Measure the voltage of the (K355) Exhaust Differential Pressure Sensor
Signal circuit in the Exhaust Differential Pressure Sensor harness con-
nector.

Is there any voltage present?

Yes

>> Repair the (K355) Exhaust Differential Pressure Sensor Sig-

nal circuit for a short to voltage.

Perform the ECM Verification Test Ver. 1 (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).

No

>> Go to 4

4.

(K951) EXHAUST DIFFERENTIAL PRESSURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE

NOTE: The jumper wire should still be in place.
Measure the voltage of the (K951) Exhaust Differential Pressure Sensor
Ground circuit in the Exhaust Differential Pressure Sensor harness con-
nector.

Is there any voltage present?

Yes

>> Repair the (K951) Exhaust Differential Pressure Sensor

Ground circuit for a short to voltage.

Perform the ECM Verification Test Ver. 1 (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).

No

>> Go to 5

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ENGINE ELECTRICAL DIAGNOSTICS - DIESEL

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5.

(K355) EXHAUST DIFFERENTIAL PRESSURE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

Turn the ignition off.

Measure the resistance of the (K355) Exhaust Differential Pressure
Sensor Signal circuit between the Exhaust Differential Pressure Sensor
harness connector and the Engine Control Module (ECM) harness con-
nector.

Is the resistance below 10.0 ohms?

Yes

>> Go to 6

No

>> Repair the (K355) Exhaust Differential Pressure Sensor Sig-

nal circuit for an open circuit or high resistance.

Perform the ECM Verification Test Ver. 1 (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).

6.

(K951) EXHAUST DIFFERENTIAL PRESSURE SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Measure the resistance of the (K951) Exhaust Differential Pressure
Sensor Ground circuit between the Exhaust Differential Pressure Sen-
sor harness connector and the Engine Control Module (ECM) harness
connector.

Is the resistance below 10.0 ohms?

Yes

>> Go to 7

No

>> Repair the (K951) Exhaust Differential Pressure Sensor

Ground circuit for an open circuit or high resistance.

Perform the ECM Verification Test Ver. 1 (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).

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7.

EXHAUST DIFFERENTIAL PRESSURE SENSOR

Turn the ignition off.

Connect the Engine Control Module (ECM) connector.

Remove the jumper wire from between cavity 30 and cavity 87 of the ASD Relay Connector.

Install the ASD Relay.

Connect a jumper wire between the (K951) Exhaust Differential Pressure Sensor Ground circuit and the (K355)
Exhaust Differential Pressure Sensor Signal circuit in the Exhaust Differential Pressure Sensor harness connector.

Turn the ignition on.

With the scan tool, Clear DTCs.

With the scan tool, select View DTCs.

NOTE: The scan tool should display an Exhaust Differential Pressure Sensor low voltage or short to ground
DTC with the jumper wire in place.

Does the scan tool display the DTC as described above?

Yes

>> Replace the Exhaust Differential Pressure Sensor in accordance with the Service Information.

Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

No

>> Go to 8

8.

ENGINE CONTROL MODULE (ECM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Exhaust Differential
Pressure Sensor and the Engine Control Module (ECM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals.

Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.

Look for the data to change or for the DTC to reset during the wiggle test.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes

>> Repair as necessary.

Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

No

>> Replace the Engine Control Module (ECM) in accordance with the Service Information.

Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

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