Test Procedure
- FD1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTC)
Are DTCs P0504, P0572, P0573, P0703, P1572 or P1703 present?
Yes No For KOEO or continuous memory DTCs P0504, P0572, P0573, P0703, P1703 and continuous memory DTC P1572, GO to FD3.
For KOER DTCs P0703, or P1703, GO to FD2.RETURN to SYMPTOM CHARTS article for further direction. - FD2 KOER DTCS P0703 AND P1703: VERIFY THE BRAKE PEDAL WAS APPLIED
Was the brake pedal applied and released during the KOER self-test?
Yes No GO to FD3. REPEAT the KOER self-test. APPLY and RELEASE the brake pedal during the KOER test.
Clear the PCM DTCs. REPEAT the self-test. - FD3 DTCS P0572, P0573, P0703, P1572 AND P1703: CHECK THE OPERATION OF THE STOPLAMPS
- Ignition ON, engine OFF.
- Apply and release the brake pedal and check the stop lamp operation.
Do the stoplamps operate correctly?
Yes No GO to FD4. REFER to the appropriate Exterior Lighting article, to diagnose all the stoplamps are inoperative.
Clear the PCM DTCs. REPEAT the self-test. - FD4 CHECK THE BPP SWITCH OPERATION
- Ignition ON, engine OFF.
- Access the PCM and monitor the BOO1 (MODE) PID.
- Apply and release the brake pedal while monitoring the brake position PID.
Does the PID cycle ON and OFF?
Yes No For Edge, Explorer, F-150, F-Series Super Duty, Focus, MKX, Motorhome / Stripped Chassis / Step Van and Mustang, GO to FD6.
For Fiesta, GO to FD15.
For all others, GO to FD13.GO to FD5. - FD5 CHECK FOR BPP CIRCUIT CYCLING
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Apply and release the brake pedal while monitoring the voltage.
- Measure the voltage between:
(+) PCM Connector, Harness Side (-) BPP Ground Is voltage less than 1 volt with the brake pedal released and greater than 10 volts with the brake pedal fully applied?
Yes No For Edge, Explorer, F-150, F-Series Super Duty, Focus, MKX, Motorhome / Stripped Chassis / Step Van and Mustang, GO to FD6.
For Fiesta, GO to FD15.
For all others, GO to FD13.REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. - FD6 CHECK BPS CIRCUIT CONTINUITY
- PCM connector disconnected.
- BPP Switch connector disconnected.
- Measure the resistance between:
(+) PCM Connector, Harness Side (-) BPP Switch Connector, Harness Side BPS BPS
Is the resistance less than 5 ohms?
Yes No GO to FD7. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. - FD7 CHECK THE BPS CIRCUIT
Is the resistance greater than 10K ohms?
Yes No GO to FD8. REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. - FD8 CHECK THE BPS CIRCUIT FOR A SHORT CIRCUIT
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) BPP Switch Connector, Harness Side (-) BPS Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test.GO to FD9. - FD9 CHECK THE SIGRTN OR GND CIRCUIT FOR AN OPEN
- Ignition OFF.
- For F-150 3.5L,
- Measure the resistance between:
(+) BPP Switch Connector, Harness Side (-) PCM Connector, Harness Side SIGRTN SIGRTN - For all others,
- Measure the resistance between:
(+) BPP Switch Connector, Harness Side (-) GND Ground
Is the resistance less than 5 ohms?
Yes No For F-150 3.5L, GO to FD10.
For all others, GO to FD11.REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - FD10 CHECK THE SIGRTN CIRCUITS FOR A SHORT TO GROUND
Is the resistance greater than 10K ohms?
Yes No GO to FD11. REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - FD11 CHECK THE SIGRTN CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- For F-150 3.5L,
- Measure the voltage between:
(+) BPP Switch Connector, Harness Side (-) SIGRTN Ground - For all others,
- Measure the voltage between:
(+) BPP Switch Connector, Harness Side (-) GND Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test.GO to FD12. - FD12 CHECK THE BPP SWITCH
- For F-150 3.5L,
- Measure the resistance between:
(+) BPP Switch Connector, Component Side (-) BPP Switch Connector, Component Side BPS SIGRTN - For all others,
- Measure the resistance between:
(+) BPP Switch Connector, Component Side (-) BPP Switch Connector, Component Side BPS GND
Is the resistance less than 5 ohms with brake pedal released and greater than 10K ohms with the brake pedal pressed?
Yes No GO to FD15. INSTALL a new BPP switch. Clear the PCM DTCs. REPEAT the self-test. - FD13 CHECK FOR BPS CIRCUIT CYCLING
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Apply and release the brake pedal while monitoring the voltage.
- Measure the voltage between:
(+) PCM Connector, Harness Side (-) BPS Ground
Is voltage greater than 10 volts with the brake pedal released and less than 1 volt with the brake pedal fully applied?
Yes No GO to FD14. REFER to the appropriate Cruise Control article. CARRY OUT the diagnostic steps for DTC P1703 to continue diagnosis. - FD14 CHECK THE BPS CIRCUIT
- PCM connector disconnected.
- Measure the resistance between:
(+) BPP Switch Connector, Harness Side (-) BPS Ground
Is the resistance less than 5 ohms?
Yes No GO to FD15. REFER to the appropriate Cruise Control article. CARRY OUT the diagnostic steps for DTC P1703 to continue diagnosis. - FD15 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test.
- Verify the concern is still present.
Is the concern still present?
Yes No INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.