Infiniti FX35, FX50 (S51). Manual - part 713

P1290, P2100, P2103 THROTTLE CONTROL MOTOR RELAY

EC-393

< DTC/CIRCUIT DIAGNOSIS >

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P1290, P2100, P2103 THROTTLE CONTROL MOTOR RELAY

Description

INFOID:0000000005236997

Power supply for the throttle control motor is provided to the ECM via throttle control motor relay. The throttle
control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends
an ON signal to throttle control motor relay and battery voltage is provided to the ECM. When the ignition
switch is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not
provided to the ECM.

DTC Logic

INFOID:0000000005236998

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8 V.

Which DTC is detected?

P1290, P2100>>GO TO 2.
P2103 >> GO TO 3.

2.

PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P1290 AND P2100

1.

Turn ignition switch ON and wait at least 2 seconds.

2.

Start engine and let it idle for 5 seconds.

3.

Check DTC.

Is DTC detected?

YES

>> Go to 

EC-393, "Diagnosis Procedure"

.

NO

>> INSPECTION END

3.

PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P2103

1.

Turn ignition switch ON and wait at least 1 second.

2.

Check DTC.

Is DTC detected?

YES

>> Go to 

EC-393, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005236999

1.

CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1290

Throttle control motor relay 
circuit open (bank 2)

ECM detects a voltage of power source for 
throttle control motor is excessively low.

• Harness or connectors

(Throttle control motor relay circuit is 
open)

• Throttle control motor relay

P2100

Throttle control motor relay 
circuit open (bank 1)

P2103

Throttle control motor relay 
circuit short

ECM detect the throttle control motor relay is 
stuck ON.

• Harness or connectors

(Throttle control motor relay circuit is 
shorted)

• Throttle control motor relay

EC-394

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P1290, P2100, P2103 THROTTLE CONTROL MOTOR RELAY

3.

Disconnect IPDM E/R harness connector E7.

4.

Check the continuity between IPDM E/R harness connector and ECM harness connector.

5.

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

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors E3, F1
• Harness connectors F104, F105
• Harness for open or short between ECM and IPDM E/R

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

3.

CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT

1.

Check the continuity between IPDM E/R sensor harness connector and ECM harness connector.

2.

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

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors E3, F1
• Harness for open or short between ECM and IPDM E/R

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

5.

CHECK FUSE

1.

Disconnect 15 A fuse (No. 51) from IPDM E/R.

2.

Check 15 A fuse for blown.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace 15 A fuse.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace IPDM E/R.

NO

>> Repair or replace harness or connectors.

IPDM E/R

ECM

Continuity

Connector

Terminal

Connector

Terminal

E7

70

F101

25

Existed

DTC

IPDM E/R

ECM

Continuity

Connector

Terminal

Connector

Terminal

P1290

E7

54

F102

52

Existed

P2100

F101

3

P2103

F101

3

F102

52

P1421 COLD START CONTROL

EC-395

< DTC/CIRCUIT DIAGNOSIS >

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P1421 COLD START CONTROL

Description

INFOID:0000000005237000

ECM controls ignition timing and engine idle speed when engine is started with pre-warming up condition.
This control promotes the activation of three way catalyst by heating the catalyst and reduces emissions.

DTC Logic

INFOID:0000000005237001

DTC DETECTION LOGIC

NOTE:
• If DTC P1421 is displayed with other DTC, first perform the trouble diagnosis for other DTC.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT-III

1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Select “DATA MONITOR” mode with CONSULT-III.

4.

Check the indication of “COOLAN TEMP/S”.
If it is between 7

°

C (45

°

F) and 36

°

C (97

°

F), go to the following steps.

If it is below 7

°

C (45

°

F), warm engine up to more than 7

°

C (45

°

F) and retry from step 1.

If it is above 36

°

C (97

°

F), cool engine down to less than 36

°

C (97

°

F) and retry from step 1.

5.

Start engine and let it idle for 5 minutes.

6.

Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT-III” above.

Is 1st trip DTC detected?

YES

>> Go to 

EC-395, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005237002

1.

PERFORM IDLE AIR VOLUME LEARNING

Perform 

EC-25, "IDLE AIR VOLUME LEARNING : Special Repair Requirement"

.

Is Idle Air Volume Learning carried out successfully?

YES

>> GO TO 2.

NO

>> Follow the instruction of Idle Air Volume Learning.

2.

CHECK INTAKE SYSTEM

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1421

Cold start emission reduction 
strategy monitoring

ECM does not control ignition timing and engine 
idle speed properly when engine is started with 
pre-warming up condition.

• Lack of intake air volume
• Fuel injection system
• ECM

EC-396

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P1421 COLD START CONTROL

Check for the cause of intake air volume lacking. Refer to the following.
• Crushed intake air passage
• Intake air passage clogging

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace malfunctioning part

3.

CHECK FUEL INJECTION SYSTEM FUNCTION

Perform DTC Confirmation Procedure for DTC P0171, P0174. Refer to 

EC-235, "DTC Logic"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Go to 

EC-236, "Diagnosis Procedure"

 for DTC P0171, P0174.

4.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Erase DTC.

3.

Perform DTC Confirmation Procedure.
See 

EC-395, "DTC Logic"

.

Is the 1st trip DTC P1421 displayed again?

YES

>> GO TO 5.

NO

>> INSPECTION END

5.

REPLACE ECM

1.

Replace ECM.

2.

Go to 

EC-23, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Require-

ment"

.

>> INSPECTION END