FAULT CODE 456 - Fuel Pressure Sensor Circuit

© 2008 Cummins Inc., Box 3005, Columbus, IN 47202-3005 U.S.A. Printed from QuickServe® Online.All Rights Reserved. Last Modified: 15-Apr-2013

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FAULT CODE 456 - Fuel Pressure Sensor CircuitTROUBLESHOOTING SUMMARY

STEPS SPECIFICATIONS SRT CODESTEP 1: Check for other fault codes.

STEP 1A: Read the fault codes. Other active fault codes?

STEP 2: Inspect fuel pressure sensor circuit.STEP 2A: Inspect circuit for damage. No damage to circuit.

STEP 3: Check the inlet restriction.STEP 3A: Measure fuel inlet restriction. Less than 254 mm Hg [10 in Hg]

of restriction at CAPS inlet.

STEP 4: Check for air in the fuel system.STEP 4A: Verify that there is no air in the

fuel system.No air detected.

STEP 5: Check the fuel lift pump.STEP 5A: Measure the fuel lift pump flow. Fuel lift pump flow meets

specifications.

STEP 6: Check the wiring harness.STEP 6A: Inspect the engine wiring

harness and the engine controlmodule (ECM) connector pins.

No damaged pins.

STEP 6B: Check for an open circuit. Less than 10 ohms.STEP 6C: Inspect the fuel pressure sensor

circuit for a short circuit.More than 100k ohms.

STEP 6D: Inspect the fuel pressure sensorcircuit for a short circuit toground.

More than 100k ohms.

STEP 7: Clear the fault codes.STEP 7A: Disable the fault codes. Fault code disabled.STEP 7B: Clear inactive fault codes. All fault codes cleared.


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TROUBLESHOOTING STEP

STEP 1: Check for other fault codes.STEP 1A: Read the fault codes.

Condition:• Turn keyswitch ON.

Action Specification/Repair Next Step

Read the fault codes.• Use INSITE™ electronic service tool to read

the fault codes.

OKNo other active fault codes.

2A

NOT OKOther active fault codes.

Appropriatefault codetroubleshooting tree.


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STEP 2: Inspect the fuel pressure sensor circuit.STEP 2A: Inspect the fuel pressure sensor circuit for visual damage.

Condition:• Turn keyswitch to the OFF.


Check the fuel pressure supply voltage.• Make sure pins are not fretted.• Make sure sensor potting is intact.

Check the pressure sensor pig tail.• Check for wire abrasion.• Check for shorts to the rate shape tube or

adjacent wires.• Make sure wires have not come out of the

sensor or connector by flexing and tugging onwires.

• Make sure the triangular connector has notrubbed against the rate shape tube.

Use the following procedure for generalinspection techniques. Refer to Procedure019-361 in Section 19.

OKNo visual signs of damage.

3A

NOT OKVisual signs of damage.Replace the fuel pressure sensor and installthe pressure sensor bracket kit, it it is notalready installed. Reference Service Bulletin4021293 and/or 4021294.

7A


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STEP 3: Check the inlet restriction.STEP 3A: Measure the fuel inlet restriction.

Condition:• Turn keyswitch to the ON.• If intermittent issue, check the inlet restriction while duplicating the complaint.


Check the inlet restriction.• Use the following procedure in the ISC, ISCe,

QSC8.3, ISL, ISLe3, ISLe4 and QSL9Troubleshooting and Repair Manual, Bulletin4021418. Refer to Procedure 006-020 inSection 6.

OKLess than 254 mm Hg [10 in Hg] of restrictionat CAPS inlet.

4A

NOT OKMore than 254 mm Hg [10 in Hg] ofrestriction at CAPS inlet.Correct source of inlet restriction.Use the following procedure in the ISC,ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9Troubleshooting and Repair Manual, Bulletin4021418. Refer to Procedure 006-020 inSection 6.

7A


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STEP 4: Check for air in the fuel system.STEP 4A: Verify there is no air in the fuel.

Condition:• Turn keyswitch to the ON.• If intermittent issue, check for air while duplicating the complaint.


Check for air in the fuel.• Use the following procedure in the ISC, ISCe,


OKNo air detected.

5A

NOT OKAir detected.Correct source of the air leak.Use the following procedure in the ISC,ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9Troubleshooting and Repair Manual, Bulletin4021418. Refer to Procedure 006-003 inSection 6.

7A

STEP 5: Check the fuel lift pump.STEP 5A: Measure the fuel lift pump flow.

Condition:• Turn keyswitch ON.


Perform fuel lift pump flow test.• Use the following procedure in the ISC, ISCe,


OKFuel lift pump flow meets specifications.

6A

NOT OKFuel lift pump flow does not meetspecifications.Replace the fuel lift pump.Use the following procedure in the ISC,ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9Troubleshooting and Repair Manual, Bulletin4021418. Refer to Procedure 005-045 inSection 5.

7A


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STEP 6: Check the engine wiring harness.STEP 6A: Inspect the engine wiring harness and the ECM connector pins.

Condition:• Turn keyswitch OFF.• Disconnect the engine wiring harness from the ECM.• Disconnect the engine wiring harness from the fuel pressure sensor.


Inspect the engine wiring harness and ECMconnectors pins for the following:• Loose connector• Corroded pins• Bent or broken pins• Pushed back or expanded pins• Moisture in or on the connector• Missing or damaged connector seals• Dirt or debris in or on the connector pins• Connector shell broken• Wire insulation damage• Damaged connector locking tab.Use the following procedure for generalinspection techniques. Refer to Procedure019-361 in Section 19.

OKNo damaged pins.

6B

NOT OKDamaged pins.Repair or replace the engine harness orECM, whichever has the damaged pins.Repair the engine harness. Refer toProcedure 019-204 in Section 19.Replace the engine harness. Refer toProcedure 019-043 in Section 19.Replace the ECM. Refer to Procedure019-031 in Section 19.

7A


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STEP 6B: Inspect the fuel pressure sensor circuit for an open circuit.

Condition:• Turn keyswitch OFF.• Disconnect the engine wiring harness from the ECM.• Disconnect the engine wiring harness from the fuel pressure sensor.


Check for an open circuit in the fuel pressuresensor circuit.• Measure the resistance from pin-46 of the

engine wiring harness to pin-C of the fuelpressure sensor connector.

• Measure the resistance from pin-10 of theengine wiring harness to pin-A of the fuelpressure sensor connector.

• Measure the resistance from pin-19 of theengine wiring harness to pin-B of the fuelpressure sensor connector.

Refer to the wiring diagram for connector pinidentification.Use the following procedure for generalresistance measurement techniques. Refer toProcedure 019-360 in Section 19.

OKIf less than 10 ohms, no open circuit.

6C

NOT OKRepair or replace the engine wiring harness.Repair the engine harness. Refer toProcedure 019-204 in Section 19.Replace the engine harness. Refer toProcedure 019-043 in Section 19.

7A


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STEP 6C: Inspect the fuel pressure sensor circuit for a short circuit.

Condition:• Turn keyswitch ON.• Disconnect the engine wiring harness from the ECM.• Disconnect the engine wiring harness from all sensors that share the common ground.


Check for a short circuit in the fuel pressuresensor circuit.• Measure the resistance from pin-46 of the

engine wiring harness to all other pins in theECM connector.

• Measure the resistance from pin-10 of theengine wiring harness to all other pins in theECM connector.

• Measure the resistance from pin-19 of theengine wiring harness to all other pins in theECM connector.

Refer to the wiring diagram for connector pinidentification.Use the following procedure for generalresistance measurement techniques. Refer toProcedure 019-360 in Section 19.

OKIf greater than 100k ohms, no shorts.

6D


7A


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STEP 6D: Inspect the fuel pressure sensor circuit for a short circuit to ground.

Condition:• Turn keyswitch ON.• Disconnect the engine wiring harness from the ECM.• Disconnect the engine wiring harness from all sensors that share the common ground.


Check for a short circuit in the fuel pressuresensor circuit.• Measure the resistance from pin-46 of the

engine wiring harness to chassis ground.• Measure the resistance from pin-10 of the

engine wiring harness to chassis ground.• Measure the resistance from pin-19 of the

engine wiring harness to chassis ground.Refer to the wiring diagram for connector pinidentification.Use the following procedure for generalresistance measurement techniques. Refer toProcedure 019-360 in Section 19.

OKIf greater than 100k ohms, no shorts.

7A


7A


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STEP 7: Clear the fault codes.STEP 7A: Disable the fault codes.

Condition:• Connect all components.• Turn keyswitch ON.


Disable the fault codes.• Start the engine and let it idle for 1 minute.• Use INSITE™ electronic service tool to verify

that Fault Code 456 is inactive.

OKFault Code 456 inactive.

7B

NOT OKReturn to the troubleshooting steps, orcontact your local Cummins® AuthorizedRepair Location if all steps have beencompleted and checked again.

Go to theappropriatetroubleshooting chart.

STEP 7B: Clear inactive fault codes.

Condition:• Connect all components.• Turn keyswitch ON.


Clear the inactive fault codes.• Use INSITE™ electronic service tool to clear

the inactive fault codes.

OKAll fault codes cleared.

Repaircomplete.

NOT OKTroubleshoot any remaining active faultcodes.

Appropriatetroubleshooting chart.


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FAULT CODE 456 - Fuel Pressure Sensor Circuit