Infiniti M35/M45 Y50. Manual - part 689

DTC P1220 FUEL PUMP CONTROL MODULE (FPCM)

EC-1229

[VK45DE]

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2. 

CHECK FPCM POWER SUPPLY CIRCUIT

1.

Disconnect fuel pump control module (FPCM) harness connector.

2.

Turn ignition switch ON.

3.

Check voltage between FPCM terminal 2 and ground with CON-
SULT-II or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E106, B4

●

Harness for open or short between FPCM and harness connector B4

>> Repair open circuit or short to ground or short to power in harness or connectors.

4. 

CHECK FPCM GROUND CIRCUIT-I FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Check harness continuity between FPCM terminal 3 and ground.
Refer to Wiring Diagram.

3.

Also check harness for short to power.

OK or NG

OK

>> GO TO 5.

NG

>> Repair open circuit or short to power in harness or connectors.

: Vehicle front

1.

FPCM

2.

Dropping resistor

Voltage: Battery voltage

PBIB2708E

PBIB0099E

Continuity should exist.

EC-1230

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DTC P1220 FUEL PUMP CONTROL MODULE (FPCM)

5. 

CHECK FPCM GROUND CIRCUIT-II FOR OPEN AND SHORT

1.

Disconnect “fuel level sensor unit and fuel pump” harness con-
nector (1).

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Illustration shows the view with rear seat cushion and inspection
hole cover (RH) removed.

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: Vehicle front

2.

Disconnect dropping resistor harness connector.

3.

Check harness continuity between the following;
“fuel level sensor unit and fuel pump” terminal 3 and dropping resistor terminal 2, 
FPCM terminal 4 and dropping resister terminal 2.
Refer to Wiring Diagram.

4.

Check harness continuity between the following;
“fuel level sensor and fuel pump” terminal 3 and ground, 
FPCM terminal 4 and ground.
Refer to Wiring Diagram.

5.

Also check harness for short to power.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

6. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors B434, B65

●

Harness for open or short between “fuel level sensor unit and fuel pump” and dropping resistor

●

Harness for open or short between FPCM and dropping resistor

●

Harness for open or short between “fuel level sensor unit and fuel pump” and ground

●

Harness for open or short between FPCM and ground

>> Repair open circuit or short to ground or short to power in harness or connectors.

PBIB2706E

: Vehicle front

1.

FPCM

2.

Dropping resistor

Continuity should exist.

Continuity should not exist.

PBIB2708E

DTC P1220 FUEL PUMP CONTROL MODULE (FPCM)

EC-1231

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7. 

CHECK FPCM INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Disconnect ECM harness connector.

2.

Check harness continuity between ECM terminal 38 and FPCM terminal 4.
Refer to Wiring Diagram.

3.

Check harness continuity between ECM terminal 38 and ground.
Refer to Wiring Diagram.

4.

Also check harness for short to power.

OK or NG

OK

>> GO TO 9.

NG

>> GO TO 8.

8. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors B2, M13

●

Harness connectors M72, F102

●

Harness for open or short between ECM and FPCM

>> Repair open circuit or short to ground or short to power in harness or connectors.

9. 

CHECK FPCM OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminal 39 and FPCM terminal 1.
Refer to Wiring Diagram.

2.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 10.

10. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors B2, M13

●

Harness connectors M72, F102

●

Harness for open or short between ECM and FPCM

>> Repair open circuit or short to ground or short to power in harness or connectors.

11. 

CHECK FPCM

Refer to 

EC-1232, "Component Inspection"

 .

OK or NG

OK

>> GO TO 12.

NG

>> Replace FPCM.

Continuity should exist.

Continuity should not exist.

Continuity should exist.

EC-1232

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DTC P1220 FUEL PUMP CONTROL MODULE (FPCM)

12. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-857, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

NBS005L4

FUEL PUMP CONTROL MODULE

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Check voltage between FPCM terminal 4 and ground under the
following conditions.

4.

If NG, replace fuel pump control module.

: Vehicle front

1.

FPCM

2.

Dropping resistor

Condition

Voltage

When engine cranking

Approx. 0V

After starting engine

Approx. 5V

PBIB2708E

PBIB0101E