Test Procedure

KB1 CHECK FOR DTCS

Are DTCs P1233, P1234, P1235, P1236, P1237, P1238, or P1641 present?

Yes	No
For DTC P1233, GO to KB2. For DTC P1234, GO to KB56. For DTCs P1235 or P1641, GO to KB20. For DTC P1236, GO to KB68. For DTC P1237, GO to KB32. For DTC P1238, GO to KB74.	For a no start (engine cranks), GO to KB54. For all others, GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .

KB2 DTC P1233: IS DTC P1233 PRESENT IN THE KOEO SELF-TEST?

NOTE: The Ford GT is equipped with 2 FPDMs. DTC P1233 applies to the FPDM mounted in the upper position on the bracket.

Check for KOEO DTCs.

Is DTC P1233 present?

Yes	No
GO to KB3.	The PCM is now receiving a signal from the FPDM. One possible cause of DTC P1233 is that the IFS switch was tripped, then reset. For a no start (engine cranks), DISREGARD the DTC at this time. RETURN to SYMPTOM CHARTS and continue as directed. After repairing the no start, to diagnose the intermittent causes of P1233, GO to KB19. For all others, GO to KB19.

KB3 DOES THE ENGINE START?

NOTE: The Ford GT starts with 1 FPDM disabled.

Does the engine start?

Yes	No
For Ford GT, GO to KB4. For all others, to check the FPM circuit, GO to KB15.	VERIFY the IFS switch is set (button pressed). If OK, GO to KB4.

KB4 CHECK THE VOLTAGE AND GROUND CIRCUITS TO THE FPDM

FPDM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM Connector, Harness Side	( - ) FPDM Connector, Harness Side
FPDM PWR	GND

Is the voltage greater than 10 V?

Yes	No
For Ford GT, to check the FPM circuit, GO to KB15. For all others, INSTALL a new FPDM. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.	GO to KB5.

KB5 CHECK THE VOLTAGE TO THE FPDM

Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM Connector, Harness Side	( - )
FPDM PWR	Ground

Is the voltage greater than 10 V?

Yes	No
REPAIR the open circuit. The FPDM ground circuit is open. CLEAR the DTCs. REPEAT the self-test.	There is no voltage to the FPDM. For F-150, F-Super Duty, Expedition, Mark LT, and Navigator, GO to KB11. For all others, GO to KB6.

KB6 CHECK THE B+ VOLTAGE TO THE FPDM POWER SUPPLY RELAY

Key in OFF position.
FPDM PWR Relay connector disconnected.

Measure the voltage between:

( + ) FPDM PWR Relay Connector, Harness Side	( - )
B+ - Pin 3	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB7.	A B+ circuit concern is present. CHECK the condition of the related fuse/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the circuit for a short to ground before installing a new fuse/fuse link. CLEAR the DTCs. REPEAT the self-test.

KB7 CHECK THE VPWR VOLTAGE TO THE FPDM POWER SUPPLY RELAY

Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM PWR Relay Connector, Harness Side	( - )
VPWR - Pin 1	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB8.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB8 CHECK FOR GROUND TO THE FPDM POWER SUPPLY RELAY

Measure the resistance between:

( + ) FPDM PWR Relay Connector, Harness Side	( - )
GND - Pin 2	Ground

Is the resistance less than 5 ohms?

Yes	No
GO to KB9.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB9 CHECK THE FPDM PWR CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + ) FPDM Connector, Harness Side	( - ) FPDM PWR Relay Connector, Harness Side
FPDM PWR	FPDM PWR - Pin 5

Is the resistance less than 5 ohms?

Yes	No
INSTALL a new FPDM relay. CLEAR the DTCs. REPEAT the self-test.	GO to KB10.

KB10 ISOLATE THE OPEN IN THE FPDM CIRCUIT

IFS Switch connector disconnected.

Measure the resistance between:

( + ) FPDM Connector, Harness Side	( - ) IFS Switch Connector, Harness Side
FPDM PWR	FPDMPWR-B

Measure the resistance between:

( + ) FPDM PWR Relay Connector, Harness Side	( - ) IFS Switch Connector, Harness Side
FPDM PWR - Pin 5	FPDMPWR-A

Is the resistance less than 5 ohms?

Yes	No
INSTALL a new IFS switch. REFER to the appropriate FUEL TANK AND LINES article . VERIFY the IFS switch is set (button pressed). CLEAR the DTCs. REPEAT the self-test.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB11 CHECK THE FUEL PUMP FUSE

NOTE: These steps are for applications with a FPDM PWR relay integral to the PDJB.

Key in OFF position.
Check the FPDM power supply relay fuse. Refer to the appropriate SYSTEM WIRING DIAGRAMS for schematic and connector information.

Is the fuse OK?

Yes	No
GO to KB12.	INSTALL a new fuse. CHECK the associated circuits for a short to ground before installing the fuse. CLEAR the DTCs. REPEAT the self-test.

KB12 CHECK FOR VOLTAGE TO THE IFS SWITCH

IFS Switch connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) IFS Switch Connector, Harness Side	( - )
FPDMPWR-A	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB14.	GO to KB13.

KB13 CHECK THE FPDM PWR CIRCUIT FOR AN OPEN BETWEEN THE IFS AND PDJB

Key in OFF position.
PDJB connector disconnected. Refer to the appropriate SYSTEM WIRING DIAGRAMS for schematic and connector information.

Measure the resistance between:

( + ) IFS Switch Connector, Harness Side	( - ) PDJB Connector, Harness Side
FPDMPWR-A	FPDM PWR

Is the resistance less than 5 ohms?

Yes	No
CHECK the fuel pump fuse. REPAIR as necessary. If OK, INSTALL a new FP RLY/PDJB. CLEAR the DTCs. REPEAT the self-test.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB14 CHECK THE IFS FOR AN OPEN

Key in OFF position.

Measure the resistance between:

( + ) IFS Switch Connector, Component Side	( - ) IFS Switch Connector, Component Side
FPDMPWR-A	FPDMPWR-B

Is the resistance less than 5 ohms?

Yes	No
REPAIR the open circuit. The FPDM PWR circuit is open.	INSTALL a new IFS switch. REFER to the appropriate FUEL TANK AND LINES article .
CLEAR the DTCs. REPEAT the self-test.	CLEAR the DTCs. REPEAT the self-test.

KB15 CHECK THE FPM CIRCUIT FOR AN OPEN IN THE HARNESS

FPDM connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + ) FPDM Connector, Harness Side	( - ) PCM Connector, Harness Side
FPM	FPM

Is the resistance less than 5 ohms?

Yes	No
GO to KB16.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB16 CHECK THE FPM CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM Connector, Harness Side	( - )
FPM	Ground

Is the voltage less than 1 V?

Yes	No
GO to KB17.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB17 CHECK THE FPM CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Key in OFF position.

Measure the resistance between:

( + ) FPDM Connector, Harness Side	( - )
FPM	Ground

Is the resistance greater than 10K ohms?

Yes	No
GO to KB18.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB18 CHECK FOR FPM OUTPUT FROM THE FPDM

NOTE: It is OK for the voltage to cycle below this range and then return within range.

FPDM connector connected.
Key ON, engine OFF.

Measure the voltage between:

( + ) PCM Connector, Harness Side	( - )
FPM	Ground

Is the voltage between 0.02 - 1 V?

Yes	No
GO to KB82.	INSTALL a new FPDM. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.

KB19 CHECK THE CIRCUITS THAT MAY CAUSE AN INTERMITTENT LOSS OF VOLTAGE TO THE FPDM

NOTE: Be aware that P1233 could be set if the IFS switch is tripped then reset.

NOTE: With no concern present, the FPDM sends a 50% duty cycle (all OK) to the PCM on the FPM circuit. Depending on diagnostic tools, the FPM PID may display 50%, or a random value that is fluctuating between 85% and 115%.

Key ON, engine OFF.
Access the PCM and monitor the FPM PID.
Observe the FPM PID for an indication of a concern while carrying out the following:
- Shake, wiggle, and bend the FPDM GND circuit
- Shake, wiggle, and bend the FPDM PWR circuit to the FPDM
- Shake, wiggle, and bend the FPM circuit between the FPDM and the PCM
- Shake, wiggle, and bend the B+ and ground circuits to the FPDM power supply relay
- Lightly tap on the IFS switch to simulate road shock
- Lightly tap on the FPDM to simulate road shock
- Lightly tap on the FPDM power supply relay to simulate road shock

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary.	Unable to duplicate or identify the concern at this time.
CLEAR the DTCs. REPEAT the self-test.	GO to Pinpoint Test Z .

KB20 DTC P1235: IS DTC P1235 PRESENT IN THE KOEO SELF-TEST?

NOTE: The Ford GT is equipped with 2 FPDMs. DTC P1235 applies to the FPDM mounted in the upper position on the bracket.

NOTE: For ETC applications, check if ETC DTC P2105 is present. An ETC system concern could cause P1235, and should be diagnosed first.

Check for KOEO DTCs.

Is DTC P1235 present?

Yes	No
GO to KB21.	For LS, GO to KB30. For all others, GO to KB31.

KB21 CHECK THE FP CIRCUIT FOR AN OPEN IN THE HARNESS

NOTE: For the LS, the FPDM functions are incorporated into the rear electronics module (REM). In the following steps, if directed to carry out an action with the FPDM, carry out the action with the REM.

FPDM connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) FPDM Connector, Harness Side
FP	FP

Is the resistance less than 5 ohms?

Yes	No
GO to KB22.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB22 CHECK THE FP CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

FPDM2 connector disconnected (Ford GT).
Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM Connector, Harness Side	( - )
FP	Ground

Is the voltage less than 1 V?

Yes	No
GO to KB23.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB23 CHECK THE FP CIRCUIT FOR A SHORT TO GROUND

Key in OFF position.

Measure the resistance between:

( + ) FPDM Connector, Harness Side	( - )
FP	Ground

Is the resistance greater than 10K ohms?

Yes	No
For Focus, and Taurus, GO to KB24. For LS, GO to KB26. For all others, GO to KB25.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB24 CHECK THE FP CIRCUIT IN THE FPDM

FPDM connector connected.
Key ON, engine OFF.

Measure the voltage between:

( + ) PCM Connector, Harness Side	( - )
FP	Ground

Is the voltage between 4.5 - 5.5 V?

Yes	No
GO to KB82.	INSTALL a new FPDM. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.

KB25 CHECK THE FP CIRCUIT IN THE FPDM

FPDM connector connected.
FPDM2 connector disconnected (Ford GT).
Key ON, engine OFF.

Measure the voltage between:

( + ) PCM Connector, Harness Side	( - )
FP	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB82.	INSTALL a new FPDM. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.

KB26 CHECK THE FPF PID

PCM connector connected.
REM connector connected.
Key ON, engine OFF.
Access the PCM and monitor the FPF PID.
While viewing the FPF PID, check if the PID indicates YES sometime within 20 seconds.

Does the FPF PID indicate YES sometime within 20 seconds?

Yes	No
GO to KB29.	GO to KB27.

KB27 CHECK THE FP PID

Access the PCM and monitor the FP PID.

Is the duty cycle between 70 - 80%?

Yes	No
GO to KB28.	GO to KB82.

KB28 CHECK THE PWM_DC1 PID

Access the REM and monitor the PWM_DC1 PID.

Is the duty cycle between 70 - 80%?

Yes	No
Unable to duplicate or identify the concern at this time. DISREGARD DTC P1235 at this time. RETURN to SYMPTOM CHARTS for further direction.	INSTALL a new REM. REFER to the appropriate MULTIFUNCTION ELECTRONIC MODULES article . CLEAR the DTCs. REPEAT the self-test.

KB29 CHECK THE REM CIRCUITRY VOLTAGE ON THE FP CIRCUIT AT THE PCM

Key in OFF position.
PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) PCM Connector, Harness Side	( - )
FP	Ground

Is the voltage greater than 8 V?

Yes	No
GO to KB82.	INSTALL a new REM. REFER to the appropriate MULTIFUNCTION ELECTRONIC MODULES article . CLEAR the DTCs. REPEAT the self-test.

KB30 CHECK THE FP CIRCUIT(S) FOR INTERMITTENT CONCERNS

NOTE: The PID value changes when a concern is present.

Key ON, engine OFF.
Access the REM and monitor the PWM_DC1 PID.
Observe the PWM_DC1 PID for an indication of a concern while carrying out the following:
- Shake, wiggle, and bend the FP circuit between the PCM and REM
- Lightly tap on the FPDM to simulate road shock

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary.	Unable to duplicate or identify the concern at this time.
CLEAR the DTCs. REPEAT the self-test.	GO to Pinpoint Test Z .

KB31 CHECK THE FP CIRCUIT FOR AN INTERMITTENT OPEN OR SHORTS

Key ON, engine OFF.
Access the PCM and monitor the FPM PID.
Observe the FPM PID for an indication of a concern while carrying out the following:
- Shake, wiggle, and bend the FP circuit between FPDM and the PCM
- Lightly tap on the FPDM to simulate road shock

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary.	Unable to duplicate or identify the concern at this time.
CLEAR the DTCs. REPEAT the self-test.	GO to Pinpoint Test Z .

KB32 DTC P1237: IS DTC P1237 PRESENT IN THE KOEO SELF-TEST?

NOTE: The Ford GT is equipped with 2 FPDMs. DTC P1237 applies to the FPDM mounted in the upper position on the bracket.

Check for KOEO DTCs.

Is DTC P1237 present?

Yes	No
GO to KB33.	DTC P1237 is possibly intermittent. For LS, GO to KB50. For all others, GO to KB39.

KB33 DOES THE ENGINE START?

NOTE: The Ford GT starts with 1 FPDM disabled.

FPDM2 connector disconnected (Ford GT).

Does the engine start?

Yes	No
For LS, GO to KB53.	For LS, GO to KB44.
For all others, GO to KB42.	For all others, GO to KB34.

KB34 CHECK THE FPPWR, FPRTN AND INTERNAL FUEL PUMP CIRCUIT RESISTANCE

Key in OFF position.
FPDM connector disconnected.

Measure the resistance between:

( + ) FPDM Connector, Harness Side	( - ) FPDM Connector, Harness Side
FPPWR	FPRTN

Is the resistance less than 10 ohms?

Yes	No
GO to KB35.	ISOLATE the concern, GO to KB38.

KB35 CHECK THE FPRTN CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM Connector, Harness Side	( - )
FPRTN	Ground

Is the voltage less than 1 V?

Yes	No
GO to KB36.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB36 CHECK THE FPPWR CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

FP connector disconnected.

Measure the resistance between:

( + ) FPDM Connector, Harness Side	( - )
FPPWR	Ground

Is the resistance greater than 10K ohms?

Yes	No
GO to KB37.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB37 CHECK FOR VOLTAGE TO FP

NOTE: During output test mode, the fuel pump stays commanded on for only about 5 seconds.

FPDM connector connected.
FP connector disconnected.
Key ON, engine OFF.
Enter output test mode. Refer to OUTPUT TEST MODE (OTM) .
Command the outputs ON.

Measure the voltage between:

( + ) FP Connector, Harness Side	( - ) FP Connector, Harness Side
FPPWR	FPRTN

Is the voltage greater than 10 V?

Yes	No
INSTALL a new FP. REFER to the appropriate FUEL TANK AND LINES article . CLEAR the DTCs. REPEAT the self-test.	VERIFY the vehicle battery was at a proper charge during the test. VERIFY the pump ON command did not timeout before the voltage check was made. REPEAT as necessary. If OK, INSTALL a new FPDM. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.

KB38 ISOLATE THE OPEN CIRCUIT

FP connector disconnected.

Measure the resistance between:

( + ) FP Connector, Harness Side	( - ) FPDM Connector, Harness Side
FPPWR	FPPWR
FPRTN	FPRTN

Measure the resistance between:

( + ) FP Connector, Component Side	( - ) FP Connector, Component Side
FPPWR	FPRTN

Is the resistance less than 10 ohms?

Yes	No
Unable to duplicate or identify the concern at this time.	REPAIR the open circuit. If the open is internal to the pump, INSTALL a new FP. REFER to the appropriate FUEL TANK AND LINES article .
GO to Pinpoint Test Z .	CLEAR the DTCs. REPEAT the self-test.

KB39 VERIFY THE DTC P1237 IS INTERMITTENT

Key ON, engine OFF.
Access the PCM and monitor the FPM PID.

Is the FPM PID 75% (or varying between 250% and 400%)?

Yes	No
A concern is present.	CHECK for an intermittent concern,
GO to KB33.	GO to KB40.

KB40 CHECK THE FPPWR AND FPRTN CIRCUIT FOR AN INTERMITTENT OPEN OR SHORTS

Key ON, engine OFF.
Access the PCM and monitor the FPM PID.
Observe the FPM PID for an indication of a concern while carrying out the following:
- Shake, wiggle, and bend the FPPWR and FPRTN circuits between the FPDM and the FP
- Lightly tap on the FP and FPDM to simulate road shock

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test.	GO to KB41.

KB41 CHECK THE FPPWR CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

NOTE: The lamp turns on when a concern is present.

Key in OFF position.
FPDM connector disconnected.

Connect a non-powered test lamp between:

( + ) FPDM Connector, Harness Side	( - ) FPDM Connector, Harness Side
FPPWR	FPDM PWR

Key ON, engine OFF.
Observe the test lamp for an indication of a concern. Shake, wiggle, and bend the FPPWR circuit between the FPDM and the FP.

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary.	Unable to duplicate or identify the concern at this time.
CLEAR the DTCs. REPEAT the self-test.	GO to Pinpoint Test Z .

KB42 CHECK THE FPPWR CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

FPDM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM Connector, Harness Side	( - )
FPPWR	Ground

Is the voltage less than 1 V?

Yes	No
GO to KB43.	REPAIR the short circuit to PWR. CLEAR the DTCs. REPEAT the self-test.

KB43 CHECK THE FPRTN CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

FPDM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM Connector, Harness Side	( - ) FPDM Connector, Harness Side
FPDM PWR	FPRTN

Is the voltage less than 1 V?

Yes	No
INSTALL a new FPDM. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.	REPAIR the short circuit to GND. CLEAR the DTCs. REPEAT the self-test.

KB44 CHECK THE REM/FP PWR AND GROUND CIRCUIT TO THE REM

NOTE: Verify the IFS switch is not tripped.

REM-J1 connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) REM-J1 Connector, Harness Side	( - ) REM-J1 Connector, Harness Side
REM/FP PWR	GND

Is the voltage greater than 10 V?

Yes	No
For these applications, the FPDM functions are incorporated into the REM. In the following steps, if directed to carry out an action with the FPDM, carry out the action with the REM. GO to KB34.	GO to KB45.

KB45 CHECK THE REM/FP PWR CIRCUIT FOR VOLTAGE TO THE REM

Key ON, engine OFF.

Measure the voltage between:

( + ) REM-J1 Connector, Harness Side	( - )
REM/FP PWR	Ground

Is the voltage greater than 10 V?

Yes	No
REPAIR the open circuit. The FPDM ground circuit is open. CLEAR the DTCs. REPEAT the self-test.	GO to KB46.

KB46 CHECK THE B+ VOLTAGE TO THE FP/REM POWER SUPPLY RELAY

Key in OFF position.
FP/REM PWR Relay connector disconnected.

Measure the voltage between:

( + ) FP/REM PWR Relay Connector, Harness Side	( - )
B+ - Pin 3	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB47.	A B+ circuit concern is present. CHECK the condition of the related fuse/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the circuit for a short to ground before installing a new fuse/fuse link. CLEAR the DTCs. REPEAT the self-test.

KB47 CHECK FOR IGN START/RUN VOLTAGE (THROUGH THE IFS SWITCH) TO THE RELAY HARNESS CONNECTOR

REM-J3 connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) FP/REM PWR Relay Connector, Harness Side	( - )
IGN START/RUN - Pin 2	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB48.	ISOLATE the concern, GO to KB52.

KB48 CHECK THE GROUND CIRCUIT TO FP/REM PWR RLY

Key in OFF position.

Measure the resistance between:

( + ) FP/REM PWR Relay Connector, Harness Side	( - )
GND - Pin 1	Ground

Is the resistance less than 5 ohms?

Yes	No
GO to KB49.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB49 CHECK REM/FP PWR CIRCUIT CONTINUITY

Measure the resistance between:

( + ) FP/REM PWR Relay Connector, Harness Side	( - ) REM-J1 Connector, Harness Side
REM/FP PWR - Pin 5	REM/FP PWR

Is the resistance less than 5 ohms?

Yes	No
INSTALL a new FP/REM PWR relay. CLEAR the DTCs. REPEAT the self-test.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB50 CHECK THE REMJ1 GND AND CIRCUITS ASSOCIATED WITH THE FPDM PWR RLY FOR INTERMITTENTS

NOTE: The lamp turns off when a concern is present.

REMJ1 connector disconnected.

Connect a non-powered test lamp between:

( + ) REM-J1 Connector, Harness Side	( - ) REM-J1 Connector, Harness Side
REM/FP PWR	GND

Key ON, engine OFF.
Observe the test lamp for an indication of a concern while carrying out the following:
- Shake, wiggle, and bend the REM/FP PWR and GND circuits to REM
- Shake, wiggle, and bend the circuits going to the FPDM PWR RLY
- Lightly tap on the FPDM PWR RLY and IFS to simulate road shock

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test.	GO to KB51.

KB51 CHECK THE FPPWR AND FPRTN CIRCUIT(S) FOR INTERMITTENT CONCERNS

NOTE: The resistance changes suddenly when a concern is present.

Key in OFF position.

Measure the resistance between:

( + ) REM-J1 Connector, Harness Side	( - ) REM-J1 Connector, Harness Side
FPPWR	FPRTN

Observe the digital multimeter (DMM) for an indication of a concern. Shake, wiggle, and bend the FPPWR and FPRTN circuits between the FP and the REM.

Measure the resistance between:

( + ) REM-J1 Connector, Harness Side	( - )
FPRTN	Ground

Observe the DMM for an indication of a concern. Shake, wiggle, and bend the FPPWR and FPRTN circuits between the FP and the REM.

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary.	Unable to duplicate or identify the concern at this time. CONNECT the REM.
CLEAR the DTCs. REPEAT the self-test.	GO to Pinpoint Test Z .

KB52 ISOLATE THE OPEN IN THE IGN START/RUN CIRCUIT

IFS Switch connector disconnected.

Measure the resistance between:

( + ) IFS Switch Connector, Component Side	( - ) IFS Switch Connector, Component Side
IGN START/RUN-A	IGN START/RUN-B

Measure the resistance between:

( + ) FPDM PWR Relay Connector, Harness Side	( - ) IFS Switch Connector, Harness Side
IGN START/RUN	IGN START/RUN-B

Is the resistance less than 5 ohms?

Yes	No
REPAIR the open circuit. CLEAR the DTCs.	INSTALL a new IFS switch. REFER to the appropriate FUEL TANK AND LINES article .
REPEAT the self-test.	CLEAR the DTCs. REPEAT the self-test.

KB53 CHECK THE FPRTN CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

REM-J1 connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) REM-J1 Connector, Harness Side	( - ) REM Connector, Harness Side
REM/FP PWR	FPRTN

Is the voltage less than 1 V?

Yes	No
GO to KB50.	REPAIR the short circuit to GND. CLEAR the DTCs. REPEAT the self-test.

KB54 CARRY OUT THE REM SELF-TEST TO VERIFY THE IFS SWITCH INPUT TO THE REM

Carry out the REM self-test. Refer to the appropriate MULTIFUNCTION ELECTRONIC MODULES article .
Check the REM for self-test DTCs.

Is DTC B2172 present?

Yes	No
GO to KB55.	GO to Pinpoint Test A .

KB55 DTC B2172: CHECK THE IFS SWITCH INPUT CIRCUIT TO THE REM

REM-J3 connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) REM-J3 Connector, Harness Side	( - )
IFS	Ground

Is the voltage greater than 10 V?

Yes

If the engine is a no start and REM DTC B2172 is received in on-demand self-test mode, INSTALL a new REM. REFER to the appropriate MULTIFUNCTION ELECTRONIC MODULES article . CLEAR the DTCs. REPEAT the selftest.
If the engine starts or REM DTC B2172 is a continuous memory DTC, the DTC is possibly intermittent.
If the engine is a no start, RETURN to SYMPTOM CHARTS to continue diagnosis.
If the engine starts,
GO to Pinpoint Test Z .

CHECK the IFS switch for an open. REPAIR as necessary.
If OK,
REPAIR the open circuit.
CLEAR the DTCs. REPEAT the self-test.

KB56 DTC P1234: IS DTC P1234 PRESENT IN THE KOEO SELF-TEST?

NOTE: The Ford GT is equipped with 2 FPDMs. DTC P1234 applies to FPDM2, which is mounted in the lower position on the bracket.

Check for KOEO DTCs.

Is DTC P1234 present?

Yes	No
GO to KB57.	The PCM is now receiving a signal from FPDM2. One possible cause of DTC P1234 is that the IFS switch was tripped, then reset. GO to KB67.

KB57 CHECK THE VOLTAGE AND GROUND CIRCUITS TO THE FPDM2

FPDM2 connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM2 Connector, Harness Side	( - ) FPDM2 Connector, Harness Side
FPDM2 PWR - Pin 5	GND - Pin 3

Is the voltage greater than 10 V?

Yes	No
To check the FPM2 circuit, GO to KB63.	GO to KB58.

KB58 CHECK VOLTAGE TO FPDM2

Measure the voltage between:

( + ) FPDM2 Connector, Harness Side	( - )
FPDM2 PWR - Pin 5	Ground

Is the voltage greater than 10 V?

Yes	No
REPAIR the open circuit. The FPDM2 ground circuit is open.	There is no voltage to the FPDM2.
CLEAR the DTCs. REPEAT the self-test.	GO to KB59.

KB59 CHECK THE B+ VOLTAGE TO THE FPDM2 POWER SUPPLY RELAY

Key in OFF position.
FPDM2 PWR Relay connector disconnected.

Measure the voltage between:

( + ) FPDM2 PWR Relay Connector, Harness Side	( - )
B+ - Pin 3	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB60.	A B+ circuit concern is present. CHECK the condition of the related fuse/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the circuit for a short to ground before installing a new fuse/fuse link. CLEAR the DTCs. REPEAT the self-test.

KB60 CHECK THE VPWR VOLTAGE TO THE FPDM2 POWER SUPPLY RELAY

Measure the voltage between:

( + ) FPDM2 PWR Relay Connector, Harness Side	( - )
VPWR - Pin 1	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB61.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB61 CHECK FOR GROUND TO THE FPDM2 POWER SUPPLY RELAY

Key in OFF position.

Measure the resistance between:

( + ) FPDM2 PWR Relay Connector, Harness Side	( - )
GND - Pin 2	Ground

Is the resistance less than 5 ohms?

Yes	No
GO to KB62.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB62 CHECK THE FPDM2 PWR CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + ) FPDM2 Connector, Harness Side	( - ) FPDM2 PWR Relay Connector, Harness Side
FPDM2 PWR - Pin 5	FPDM2 PWR - Pin 5

Is the resistance less than 5 ohms?

Yes	No
INSTALL a new FPDM2 PWR relay. CLEAR the DTCs. REPEAT the self-test.	GO to KB67.

KB63 CHECK THE FPM2 CIRCUIT FOR AN OPEN IN THE HARNESS

Key in OFF position.
FPDM2 connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + ) FPDM2 Connector, Harness Side	( - ) PCM Connector, Harness Side
FPM2 - Pin 1	FPM2

Is the resistance less than 5 ohms?

Yes	No
GO to KB64.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB64 CHECK THE FPM2 CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM2 Connector, Harness Side	( - )
FPM2 - Pin 1	Ground

Is the voltage less than 1 V?

Yes	No
GO to KB65.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB65 CHECK THE FPM2 CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Key in OFF position.

Measure the resistance between:

( + ) FPDM2 Connector, Harness Side	( - )
FPM2 - Pin 1	Ground

Is the resistance greater than 10K ohms?

Yes	No
GO to KB66.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB66 CHECK FOR FPM2 OUTPUT FROM THE FPDM2

NOTE: It is OK for the voltage to cycle below this range and then return within range.

FPDM2 connector connected.
Key ON, engine OFF.

Measure the voltage between:

( + ) PCM Connector, Harness Side	( - )
FPM2	Ground

Is the voltage between 0.02 - 1 V?

Yes	No
GO to KB82.	INSTALL a new FPDM2. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.

KB67 CHECK CIRCUITS THAT MAY CAUSE AN INTERMITTENT LOSS OF VOLTAGE SUPPLY TO THE FPDM2

NOTE: Be aware that P1234 could be set if the IFS switch is tripped then reset.

NOTE: With no concern present, the FPDM2 sends a 50% duty cycle (all OK) to the PCM on the FPM2 circuit. Depending on diagnostic tools, the FPM2 PID may display 50%, or a random value that is fluctuating between 85% and 115%.

Key ON, engine OFF.
Access the PCM and monitor the FPM2 PID.
Observe the FPM2 PID for an indication of a concern while carrying out the following:
- Shake, wiggle, and bend the FPDM2 GND circuit
- Shake, wiggle, and bend the FPDM2 PWR circuit to the FPDM2
- Shake, wiggle, and bend the FPM2 circuit between the FPDM2 and the PCM
- Shake, wiggle, and bend the B+ and ground circuits to the FPDM2 power supply relay
- Lightly tap on the IFS switch to simulate road shock
- Lightly tap on the FPDM2 to simulate road shock
- Lightly tap on the FPDM2 power supply relay to simulate road shock

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary.	Unable to duplicate or identify the concern at this time.
CLEAR the DTCs. REPEAT the self-test.	GO to Pinpoint Test Z .

KB68 DTC P1236: IS DTC P1236 PRESENT IN THE KOEO SELF-TEST?

The Ford GT is equipped with 2 FPDMs. DTC P1236 applies to FPDM2, which is mounted in the lower position on the bracket.
Check for KOEO DTCs.

Is DTC P1236 present?

Yes	No
GO to KB69.	GO to KB73.

KB69 CHECK THE FP CIRCUIT FOR AN OPEN IN THE HARNESS

Key in OFF position.
FPDM2 connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) FPDM2 Connector, Harness Side
FP	FP - Pin 6

Is the resistance less than 5 ohms?

Yes	No
GO to KB70.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KB70 CHECK THE FP CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

FPDM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM2 Connector, Harness Side	( - )
FP - Pin 6	Ground

Is the voltage less than 1 V?

Yes	No
GO to KB71.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB71 CHECK THE FP CIRCUIT FOR A SHORT TO GROUND

Key in OFF position.

Measure the resistance between:

( + ) FPDM2 Connector, Harness Side	( - )
FP - Pin 6	Ground

Is the resistance greater than 10K ohms?

Yes	No
GO to KB72.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB72 CHECK THE FP CIRCUIT IN THE FPDM2

FPDM2 connector connected.
Key ON, engine OFF.

Measure the voltage between:

( + ) PCM Connector, Harness Side	( - )
FP	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KB82.	INSTALL a new FPDM2. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.

KB73 CHECK THE FP CIRCUIT FOR AN INTERMITTENT OPEN OR SHORTS

Key ON, engine OFF.
Access the PCM and monitor the FPM2 PID.
Observe the FPM2 PID for an indication of a concern while carrying out the following:
- Shake, wiggle, and bend the FP circuit between FPDM2 and the PCM
- Lightly tap on the FPDM2 to simulate road shock

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary.	Unable to duplicate or identify the concern at this time.
CLEAR the DTCs. REPEAT the self-test.	GO to Pinpoint Test Z .

KB74 DTC P1238: IS DTC P1238 PRESENT IN THE KOEO SELF-TEST?

NOTE: The Ford GT is equipped with 2 FPDMs. DTC P1238 applies to FPDM2, which is mounted in the lower position on the bracket.

Check for KOEO DTCs.

Is DTC P1238 present?

Yes	No
GO to KB75.	CHECK for an intermittent concern, GO to KB81.

KB75 CHECK THE FP2PWR, FP2RTN AND INTERNAL FUEL PUMP CIRCUIT RESISTANCE

Key in OFF position.
FPDM2 connector disconnected.

Measure the resistance between:

( + ) FPDM2 Connector, Harness Side	( - ) FPDM2 Connector, Harness Side
FP2PWR - Pin 4	FP2RTN - Pin 2

Is the resistance less than 10 ohms?

Yes	No
GO to KB76.	ISOLATE the concern, GO to KB80.

KB76 CHECK THE FP2PWR AND FP2RTN CIRCUIT(S) FOR A SHORT TO VOLTAGE IN THE HARNESS

Key in OFF position.
FP connector disconnected. Refer to the appropriate SYSTEM WIRING DIAGRAMS for schematic and connector information.
Key ON, engine OFF.

Measure the voltage between:

( + ) FPDM2 Connector, Harness Side	( - )
FP2PWR - Pin 4	Ground
FP2RTN - Pin 2	Ground

Are the voltages less than 1 V?

Yes	No
GO to KB77.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB77 CHECK THE FP2PWR AND FP2RTN CIRCUIT(S) FOR A SHORT TO GROUND IN THE HARNESS

Key in OFF position.

Measure the resistance between:

( + ) FPDM2 Connector, Harness Side	( - )
FP2PWR - Pin 4	Ground
FP2RTN - Pin 2	Ground

Are the resistances greater than 10K ohms?

Yes	No
GO to KB78.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB78 CHECK FOR A SHORT BETWEEN THE FP2PWR AND FP2RTN CIRCUITS

Measure the resistance between:

( + ) FPDM2 Connector, Harness Side	( - ) FPDM2 Connector, Harness Side
FP2PWR - Pin 4	FP2RTN - Pin 2

Is the resistance greater than 10K ohms?

Yes	No
GO to KB79.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KB79 CHECK FOR VOLTAGE TO THE FP

NOTE: During output test mode, the fuel pump stays commanded on for only about 5 seconds.

FPDM2 connector connected.
Key ON, engine OFF.
Enter output test mode. Refer to OUTPUT TEST MODE (OTM) .
Command the outputs ON.

Measure the voltage between:

( + ) FP Connector, Harness Side	( - ) FP Connector, Harness Side
FP2PWR	FP2RTN

Is the voltage greater than 10 V?

Yes	No
INSTALL a new FP. REFER to the appropriate FUEL TANK AND LINES article . CLEAR the DTCs. REPEAT the self-test.	VERIFY the vehicle battery was at a proper charge during the test. VERIFY the pump ON command did not time out before the voltage check was made. REPEAT as necessary. If OK, INSTALL a new FPDM2. REFER to the appropriate FUEL CHARGING & CONTROLS article . CLEAR the DTCs. REPEAT the self-test.

KB80 ISOLATE THE OPEN CIRCUIT

FP connector disconnected. Refer to the appropriate SYSTEM WIRING DIAGRAMS for schematic and connector information.

Measure the resistance between:

( + ) FP Connector, Harness Side	( - ) FPDM2 Connector, Harness Side
FP2PWR	FP2PWR - Pin 4
FP2RTN	FP2RTN - Pin 2

Measure the resistance between:

( + ) FP Connector, Component Side	( - ) FP Connector, Component Side
FP2PWR	FP2RTN

Is the resistance less than 10 ohms?

Yes	No
Unable to duplicate or identify the concern at this time.	REPAIR the open circuit. If the open is internal to the pump, INSTALL a new FP. REFER to the appropriate FUEL TANK AND LINES article .
GO to Pinpoint Test Z .	CLEAR the DTCs. REPEAT the self-test.

KB81 CHECK THE FP2PWR AND FP2RTN CIRCUIT FOR AN INTERMITTENT OPEN OR SHORTS

Key ON, engine OFF.
Access the PCM and monitor the FPM2 PID.
Observe the FPM2 PID for an indication of a concern while carrying out the following:
- Shake, wiggle, and bend the FP2PWR and FP2RTN circuits between the FPDM2 and the FP
- Lightly tap on the FP and FPDM2 to simulate road shock

Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test.	GO to Pinpoint Test Z .

KB82 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 and 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) .	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.