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Nissan Titan. Manual - part 270

P1220 FUEL PUMP CONTROL MODULE (FPCM)

EC-381

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

P1220 FUEL PUMP CONTROL MODULE (FPCM)

Description

INFOID:0000000009886815

SYSTEM DESCRIPTION

*: ECM determines the start signal status by the signals of engine speed and battery voltage.

This system controls the fuel pump operation. The amount of fuel flow delivered from the fuel pump is altered

between two flow rates by the FPCM operation. The FPCM determines the voltage supplied to the fuel pump

(and therefore fuel flow) according to the following conditions.

COMPONENT DESCRIPTION

The FPCM adjusts the voltage supplied to the fuel pump to control

the amount of fuel flow. When the FPCM increases the voltage sup-

plied to the fuel pump, the fuel flow is increased. When the FPCM

decreases the voltage, the fuel flow is decreased.

On Board Diagnosis Logic

INFOID:0000000009886816

DTC Confirmation Procedure

INFOID:0000000009886817

CAUTION:

Always drive vehicle at a safe speed.

NOTE:

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:

Sensor

Input Signal to ECM

ECM function

Actuator

Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)

Engine speed*

Fuel pump control

Fuel pump control module
(FPCM)

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Battery

Battery voltage*

Conditions

Amount of fuel flow

Supplied voltage

• Engine cranking
• Engine coolant temperature is below 10

°C (50°F).

• Engine is running under heavy load and high speed conditions

high

Battery voltage
(11 - 14V)

Except the above

low

Approximately 8V

BBIA0601E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1220
1220

Fuel pump control module
(FPCM)

An improper voltage signal from the FPCM, which is
supplied to a point between the fuel pump and the
dropping resistor, is detected by ECM.

• Harness or connectors

(FPCM circuit is shorted.)

• Dropping resistor
• FPCM

EC-382

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

P1220 FUEL PUMP CONTROL MODULE (FPCM)

Before performing the following procedure, confirm that battery voltage is more than 11V with ignition

switch ON.

1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT.

2. Make sure that “COOLAN TEMP/S” indicates less than 70

°C (158°F). If not, cool down the engine.

3. Start engine.

4. Hold vehicle at the following conditions for 12 seconds.

5. Check 1st trip DTC.

6. If 1st trip DTC is detected, go to

EC-382, "Diagnosis Procedure"

Diagnosis Procedure

INFOID:0000000009886818

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

2. Loosen and retighten three ground screws on the body.

Refer to

EC-154, "Ground Inspection"

OK or NG

>> GO TO 2.

>> Repair or replace ground connections.

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 4 and ground with CON-

SULT or tester.

OK or NG

>> GO TO 4.

>> GO TO 3.

ENG SPEED

1,100 - 2,600 rpm

VHCL SPEED SE

More than 70 km/h (43 MPH)

B/FUEL SCHDL

0 - 25 msec

Selector lever

Suitable position

BBIA0354E

Voltage: Battery voltage

BBIA0599E

PBIB2754E

P1220 FUEL PUMP CONTROL MODULE (FPCM)

EC-383

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

DETECT MALFUNCTIONING PART

Check the following.

• Harness for open or short between FPCM and IPDM E/R

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

CHECK FPCM GROUND CIRCUIT-I FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Check harness continuity between FPCM terminal 1 and ground.

Refer to Wiring Diagram.

3. Also check harness for short to power.
OK or NG

>> GO TO 5.

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

CHECK FPCM GROUND CIRCUIT-II FOR OPEN AND SHORT

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

nector.

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 2 and dropping resister terminal 2.

Refer to Wiring Diagram.

4. Check harness continuity between the following;

FPCM terminal 2 and ground,

“fuel level sensor and fuel pump” terminal 3 and ground.

Refer to Wiring Diagram.

5. Also check harness for short to power.
OK or NG

>> GO TO 7.

>> GO TO 6.

DETECT MALFUNCTIONING PART

Check the following.

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

• Harness connectors C1, E41

• Harness for open or short between FPCM and dropping resistor

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

• Harness for short between FPCM and ground

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

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 2.

Refer to Wiring Diagram.

3. Check harness continuity between ECM terminal 38 and ground.

Continuity should exist.

Continuity should not exist.

BBIA0442E

Continuity should exist.

EC-384

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

P1220 FUEL PUMP CONTROL MODULE (FPCM)

Refer to Wiring Diagram.

4. Also check harness for short to power.
OK or NG

>> GO TO 9.

>> GO TO 8.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors F32, E2

• Harness for open or short between ECM and FPCM

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

CHECK FPCM OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check harness continuity between ECM terminal 39 and FPCM terminal 3.

Refer to Wiring Diagram.

2. Also check harness for short to ground and short to power.
OK or NG

>> GO TO 11.

>> GO TO 10.

10.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors F32, E2

• 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-384, "Component Inspection"

OK or NG

>> GO TO 12.

>> Replace FPCM.

12.

CHECK INTERMITTENT INCIDENT

Refer to

GI-39, "How to Check Terminal"

and

GI-42, "Intermittent Incident"

>> INSPECTION END

Component Inspection

INFOID:0000000009886819

FUEL PUMP CONTROL MODULE (FPCM)

Continuity should not exist.

Continuity should exist.

BBIA0599E

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