Infiniti FX35, FX50 (S51). Manual - part 1656

P1612 CHAIN OF ECM-IMMU

SEC-37

< DTC/CIRCUIT DIAGNOSIS >

[INTELLIGENT KEY SYSTEM]

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P1612 CHAIN OF ECM-IMMU

Description

INFOID:0000000005249428

BCM performs the ID verification with ECM that allows the engine to start. Start the engine if the ID is OK.
ECM prevents the engine from starting if the ID is not registered. BCM starts the communication with ECM if
ignition switch is turned ON.

DTC Logic

INFOID:0000000005249429

DTC DETECTION LOGIC

NOTE:
• If DTC P1612 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to

SEC-31, "BCM : DTC Logic"

.

• If DTC P1612 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer to

SEC-33, "BCM : DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON under the following conditions.

-

Selector lever is in the P or N position.

-

Do not depress brake pedal.

2.

Check “Self diagnostic result” with CONSULT-III.

Is DTC detected?

YES

>> Go to 

SEC-37, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005249430

1.

REPLACE BCM

1.

Replace BCM. Refer to 

BCS-83, "Removal and Installation"

.

2.

Perform initialization with CONSULT-III.
For initialization, refer to “CONSULT-III Operation Manual NATS-IVIS/NVIS”.

Does the engine start?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

REPLACE ECM

Replace ECM. Refer to 

EC-20, "BASIC INSPECTION : Special Repair Requirement"

 (VQ35HR), 

EC-576,

"BASIC INSPECTION : Special Repair Requirement"

(VK50VE).

>> INSPECTION END

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

P1612

CHAIN OF ECM-IMMU

Inactive communication between ECM and BCM

• Harness or connectors

(The CAN communication line is open or 
shorted)

• BCM 
• ECM

SEC-38

< DTC/CIRCUIT DIAGNOSIS >

[INTELLIGENT KEY SYSTEM]

P1614 CHAIN OF IMMU-KEY

P1614 CHAIN OF IMMU-KEY

Description

INFOID:0000000005249431

Performs ID verification through BCM and Intelligent Key when push-button ignition switch is pressed.
Prohibits the release of steering lock or start of engine when an unregistered ID of Intelligent Key is used.

DTC Logic

INFOID:0000000005249432

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE 1

1.

Insert Intelligent Key into the key slot.

2.

Check “Self diagnostic result” with CONSULT-III.

Is DTC detected?

YES

>> Go to 

SEC-38, "Diagnosis Procedure"

.

NO

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE 2

1.

Press the push-button ignition switch.

2.

Check “Self diagnostic result” with CONSULT-III.

Is DTC detected?

YES

>> Go to 

SEC-38, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005249433

1.

 INSPECTION START

Check the case in which DTC is detected.
• Case1: It is detected when Intelligent Key is inserted into key slot.
• Case2: It is detected after Intelligent Key is inserted into key slot and push-button ignition switch is pressed.
In which case is DTC detected?

Case1. >> GO TO 2.
Case2. >> GO TO 4.

2.

CHECK KEY SLOT INPUT SIGNAL

1.

Turn ignition switch OFF.

2.

Disconnect key slot connector.

3.

Check voltage between key slot harness connector and ground.

Is the inspection result normal?

YES

>> Replace key slot. Refer to 

SEC-219, "Removal and Installation"

.

NO

>> GO TO 3.

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

P1614

CHAIN OF IMMU-
KEY

Inactive communication between key slot and 
BCM.

• Harness or connectors

(The key slot circuit is open or 
shorted)

• Key  slot 
• BCM

(+)

(–)

Voltage (V)

(Approx.)

Key slot

Connector

Terminal

M22

2

Ground

Battery voltage

P1614 CHAIN OF IMMU-KEY

SEC-39

< DTC/CIRCUIT DIAGNOSIS >

[INTELLIGENT KEY SYSTEM]

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3.

CHECK KEY SLOT CIRCUIT

1.

Disconnect BCM connector M122.

2.

Check continuity between key slot harness connector and BCM harness connector.

3.

Check continuity between key slot harness connector and ground.

Is the inspection result normal?

YES

>> Replace BCM. Refer to 

BCS-83, "Removal and Installation"

.

NO

>> Repair or replace harness.

4.

CHECK PUSH-BUTTON IGNITION SWITCH OPERATION

Press push-button ignition switch and check if it turns ON.

Does ignition switch turn to ON?

YES

>> GO TO 5.

NO

>> GO TO 7.

5.

CHECK KEY SLOT COMMUNICATION SIGNAL

1.

Turn ignition switch OFF.

2.

Disconnect key slot connector.

3.

Check voltage between key slot harness connector and ground.

Is the inspection result normal?

YES

>> Replace key slot. Refer to 

SEC-219, "Removal and Installation"

.

NO

>> GO TO 6.

6.

CHECK KEY SLOT COMMUNICATION SIGNAL CIRCUIT

1.

Disconnect BCM connector M122.

2.

Check continuity between key slot harness connector and BCM harness connector.

3.

Check continuity between key slot harness connector and ground.

Is the inspection result normal?

YES

>> Replace BCM. Refer to 

BCS-83, "Removal and Installation"

.

NO

>> Repair or replace harness.

7.

CHECK KEY SLOT GROUND CIRCUIT

Key slot

BCM

Continuity

Connector

Terminal

Connector

Terminal

M22

2

M122

80

Existed

Key slot

Ground

Continuity

Connector

Terminal

M22

2

Not existed

(+)

(–)

Voltage (V)

(Approx.)

Key slot

Connector

Terminal

M22

3

Ground

Battery voltage

Key slot

BCM

Continuity

Connector

Terminal

Connector

Terminal

M22

3

M122

81

Existed

Key slot

Ground

Continuity

Connector

Terminal

M22

3

Not existed

SEC-40

< DTC/CIRCUIT DIAGNOSIS >

[INTELLIGENT KEY SYSTEM]

P1614 CHAIN OF IMMU-KEY

1.

Turn ignition switch OFF.

2.

Disconnect key slot connector.

3.

Check continuity between key slot harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Repair or replace harness.

8.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

Key slot

Ground

Continuity

Connector

Terminal

M22

7

Existed