Test Procedure
- M1 PRELIMINARY DIAGNOSIS FOR DTCS P0230, P0231, AND P0232 NOTE: For F-SuperDuty/Excursion, the fuel pump relay is internal to the central junction box (CJB).
- Retrieve and record all DTCs.
- Record freeze frame data.
- Clear the DTCs.
- Perform the On-Demand Self-Test.
ARE ANY DTCS RETRIEVED?
Yes No For DTC P0230 (F-SuperDuty/Excursion), Go to M2.
For DTC P0230 (E-Series), Go to M3.
For P0231, Go to M8.
For P0232, Go to M14.UNABLE to duplicate condition. CHECK for loose connections, damaged or corroded terminals or pins. REPAIR as necessary. REFER to SYMPTOM CHARTS - 6.0L DIESEL if a driveability concern exists. - M2 DIAGNOSTIC TROUBLE CODE (DTC) P0230
- Possible causes:
- fuel pump relay (internal to CJB)
- circuitry
- PCM
- Key off.
- Disconnect CJB C270f.
- Key on, engine off.
- Measure the voltage between CJB C270f pin 10, component side and ground.
IS THE VOLTAGE GREATER THAN 10.5 VOLTS?
Yes No Go to M5. INSTALL a new CJB. - Possible causes:
- M3 CHECK THE FUEL PUMP RELAY VOLTAGE CIRCUIT NOTE: REFER to the appropriate SYSTEM WIRING DIAGRAMS article for PCM relay coil pin locations.
- Possible causes:
- fuel pump relay
- circuitry
- PCM
- Key off.
- Disconnect the fuel pump relay.
- Key on, engine off.
- Measure the voltage between the fuel pump relay coil power circuit, harness side and ground.
IS THE VOLTAGE GREATER THAN 10.5 VOLTS?
Yes No Go to M4. REPAIR the circuit. - Possible causes:
- M4 CHECK THE FUEL PUMP RELAY
- Perform the fuel pump relay component test. REFER to the appropriate COMPONENT TESTING article.
DOES THE FUEL PUMP RELAY PASS THE COMPONENT TEST?
Yes No Go to M5. INSTALL a new fuel pump relay. - M5 CHECK THE FUEL PUMP RELAY CONTROL CIRCUIT FOR AN OPEN NOTE: REFER to the appropriate SYSTEM WIRING DIAGRAMS for fuel pump relay coil pin locations.
- Key off.
- Disconnect the PCM body harness connector.
- Measure the resistance between the CJB C270f pin 10 (F-SuperDuty/Excursion) or the fuel pump relay coil control circuit (E-Series), harness side and the PCM body harness connector pin 5, harness side.
IS THE RESISTANCE LESS THAN 5 OHMS?
Yes No Go to M6. REPAIR the circuit. - M6 CHECK THE FUEL PUMP RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between the PCM body harness connector pin 5, harness side and ground.
IS THE RESISTANCE GREATER THAN 10,000 OHMS?
Yes No Go to M7. REPAIR the circuit. - M7 CHECK THE FUEL PUMP RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Key on, engine off.
- Measure the voltage between the PCM body harness connector pin 5, harness side and ground.
IS ANY VOLTAGE INDICATED?
Yes No REPAIR the circuit. INSTALL a new PCM. - M8 DIAGNOSTIC TROUBLE CODE (DTC) P0231 NOTE: Diagnose and repair DTC P0230 before addressing DTC P0231.
- Possible causes:
- inertia switch
- fuel pump monitor circuit open
- fuel pump relay
- Key off.
- Disconnect the inertia switch.
- Measure the resistance between the inertia switch pin 1, component side and the inertia switch pin 3 (F-SuperDuty/Excursion) or pin 2 (E-Series), component side.
IS THE RESISTANCE LESS THAN 5 OHMS?
Yes No Go to M9. INSTALL a new inertia switch. - Possible causes:
- M9 CHECK THE FUEL PUMP VOLTAGE
- Connect a test lamp between the inertia switch pin 1 (F-SuperDuty/Excursion) or pin 2 (E-Series), harness side and ground.
- Key on, engine off.
IS THE TEST LAMP ILLUMINATED FOR APPROXIMATELY 20 SECONDS?
Yes No Go to M13. For F-SuperDuty/Excursion, Go to M10.
For E-Series, Go to M11. - M10 CHECK THE FUEL PUMP VOLTAGE CIRCUIT FOR AN OPEN
- Key off.
- Disconnect CJB C270a.
- Measure the resistance between CJB C270a pin 22, harness side and the inertia switch pin 1, harness side.
IS THE RESISTANCE LESS THAN 5 OHMS?
Yes No INSTALL a new CJB. REPAIR the circuit. - M11 CHECK THE FUEL PUMP RELAY POWER CIRCUIT FOR VOLTAGE
- Key off.
- Disconnect the fuel pump relay.
- Key on, engine off.
- Measure the voltage between the fuel pump relay power circuit pin 30, harness side and ground.
IS THE VOLTAGE GREATER THAN 10.5 VOLTS?
Yes No Go to M12. REPAIR the circuit. - M12 CHECK THE FUEL PUMP RELAY
- Perform the fuel pump relay component test. REFER to the appropriate COMPONENT TESTING article.
DOES THE FUEL PUMP RELAY PASS THE COMPONENT TEST?
Yes No REPAIR the circuit. INSTALL a new fuel pump relay. - M13 CHECK THE FUEL PUMP MONITOR CIRCUIT FOR AN OPEN
- Key off.
- Disconnect the PCM.
- Measure the resistance between the inertia switch pin 3 (F-SuperDuty/Excursion) or pin 1 (E-Series), harness side and the PCM body harness connector pin 19, harness side.
IS THE RESISTANCE LESS THAN 5 OHMS?
Yes No INSTALL a new PCM. REPAIR the circuit. - M14 DIAGNOSTIC TROUBLE CODE (DTC) P0232 NOTE: Diagnose and repair DTC P0230 before addressing DTC P0232.
- Possible causes:
- fuel pump relay
- fuel pump monitor circuit open or short to voltage
- fuel pump ground circuit open
- fuel pump
- Key off.
- Disconnect central junction box (CJB) C270a (F-SuperDuty/Excursion).
- Disconnect the fuel pump relay (E-Series).
- Key on, engine off.
IS THE FUEL PUMP ON?
Yes No Go to M15. Go to M16. - Possible causes:
- M15 CHECK THE FUEL PUMP MONITOR CIRCUIT A SHORT TO VOLTAGE
- Key off.
- Disconnect the PCM body harness connector.
- Disconnect the fuel pump.
- Key on, engine off.
- Measure the voltage between the PCM body harness connector pin 19, harness side and ground.
IS ANY VOLTAGE INDICATED?
Yes No REPAIR the circuit. CLEAR the DTCs and RETEST the system. If the DTC P0232 is present again, INSTALL a new PCM. - M16 CHECK THE FUEL PUMP GROUND FOR AN OPEN
- Key off.
- Disconnect the fuel pump.
- Measure the resistance between the fuel pump ground pin 2, harness side and ground.
IS THE RESISTANCE LESS THAN 5 OHMS?
Yes No Go to M17 REPAIR the circuit. - M17 CHECK THE FUEL PUMP
- Measure the resistance between the fuel pump pin 1, component side and the fuel pump pin 2, component side.
IS THE RESISTANCE LESS THAN 5 OHMS?
Yes No Go to M18 INSTALL a new fuel pump. - M18 CHECK THE FUEL PUMP MONITOR CIRCUIT AN OPEN
- Disconnect the PCM body harness connector.
- Measure the resistance between the PCM body harness connector pin 19, harness side and the fuel pump pin 1, harness side.
IS THE RESISTANCE LESS THAN 5 OHMS?
Yes No For E-Series, Go to M19.
For F-SuperDuty/Excursion, Go to M20.REPAIR the circuit. - M19 CHECK THE FUEL PUMP RELAY
- Perform the fuel pump relay component test. REFER to the appropriate COMPONENT TESTING article.
DOES THE FUEL PUMP RELAY PASS THE COMPONENT TEST?
Yes No CLEAR the DTCs and RETEST the system. If the DTC P0232 is present again, INSTALL a new PCM. INSTALL a new fuel pump relay. - M20 CHECK THE CJB FUEL PUMP RELAY
- Reconnect CJB C270a.
- Connect a 5 amp fused jumper wire between the PCM body harness connector pin 5 harness side, and ground.
- Measure the voltage between the PCM body connector pin 19 harness side, and ground.
- Key on, engine off.
IS THE VOLTAGE GREATER THAN 10 VOLTS WITH THE JUMPER INSTALLED AND IS THE VOLTAGE LESS THAN 1 VOLT WITH THE JUMPER REMOVED?
Yes No CLEAR the DTCs and RETEST the system. If the DTC P0232 is present again, INSTALL a new PCM. INSTALL a new CJB. CLEAR the DTCs and RETEST the system.