Infiniti FX35, FX50 (S51). Manual - part 551

AWD CONTROL UNIT

DLN-39

< ECU DIAGNOSIS INFORMATION >

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C

E

F

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N

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Fail-Safe

INFOID:0000000005249077

AWD system

• If any malfunction occurs in AWD electrical system, and control unit detects the malfunction, AWD warning

lamp on combination meter turns ON to indicate system malfunction.

• When AWD warning lamp is ON, vehicle changes to rear-wheel drive or shifts to 4-wheel drive (front-wheels

still have some driving torque).

JCDWA0573GB

DLN-40

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AWD CONTROL UNIT

• AWD system activates its protection function (shuts down AWD system temporarily) if AWD system detects

high load continuously or the front wheel tire size differs from the rear tire size. (AWD system is automati-
cally restored if AWD system no longer detects any overload or the tire size difference is eliminated.)

*1: Quick blinking: 2 times/second (blinking for approximately 1 minute and then turned OFF)

*2: Slow blinking: 1 time/2 seconds (continuing to blink until ignition switch is turned OFF)

DTC Inspection Priority Chart

INFOID:0000000005249078

If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.

DTC Index

INFOID:0000000005249079

Mode

Warning 

lamp

DTC

Detected area (Error area)

Error area and root cause

Protection 

function

 Blinking

*1

—

AWD control unit

Transfer assembly in protection mode. It is not malfunction.
(Internal temperature rise of electronic controlled coupling)

Blinking

*2

—

Outer diameters of front and 
rear wheel tires

Malfunction in each tire or different tire diameter

Fail-safe

ON

C1201

AWD control unit

Internal malfunction of AWD control unit

C1203

ABS actuator and electric 
unit (control unit)

ABS malfunction
• Vehicle speed signal error

C1204

AWD solenoid

Internal malfunction of electronic controlled coupling

C1205

AWD control unit

Internal malfunction of AWD control unit

C1210

ECM

Malfunction of engine control system

P1804

AWD control unit

Internal malfunction of AWD control unit

P1809

AWD control unit

Internal malfunction of AWD control unit

P1826

Transfer fluid temperature 
sensor

Internal malfunction of electric controlled coupling

U1000

CAN communication line

• CAN communication error
• Malfunction of AWD control unit

U1010

AWD control unit

Malfunction of AWD control unit

Priority

Detected items (DTC)

1

• U1000 CAN COMM CIRCUIT
• U1010 CONTROL UNIT (CAN)

2

• C1201 CONTROLLER FAILURE
• C1205 4WD ACTUATOR RLY
• P1804 CONTROL UNIT 3
• P1809 CONTROL UNIT 4

3

• C1203 ABS SYSTEM
• C1210 ENGINE SIGNAL 1

4

• C1204 4WD SOLENOID
• P1826 OIL TEMP SEN

DTC

Display Items

Reference

C1201

CONTROLLER FAILURE

DLN-14, "DTC Logic"

C1203

ABS SYSTEM

DLN-15, "DTC Logic"

C1204

4WD SOLENOID

DLN-16, "DTC Logic"

C1205

4WD ACTUATOR RLY

DLN-18, "DTC Logic"

C1210

ENGINE SIGNAL 1

DLN-19, "DTC Logic"

P1804

CONTROL UNIT 3

DLN-20, "DTC Logic"

P1809

CONTROL UNIT 4

DLN-21, "DTC Logic"

AWD CONTROL UNIT

DLN-41

< ECU DIAGNOSIS INFORMATION >

[TRANSFER: ETX13C]

C

E

F

G

H

I

J

K

L

M

A

B

DLN

N

O

P

P1826

OIL TEMP SEN

DLN-22, "DTC Logic"

U1000

CAN COMM CIRCUIT

DLN-25, "DTC Logic"

U1010

CONTROL UNIT (CAN)

DLN-26, "DTC Logic"

DTC

Display Items

Reference

DLN-42

< SYMPTOM DIAGNOSIS >

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AWD WARNING LAMP DOES NOT TURN ON

SYMPTOM DIAGNOSIS

AWD WARNING LAMP DOES NOT TURN ON

Description

INFOID:0000000005249080

AWD warning lamp does not turn ON when the ignition switch is turned to ON.

Diagnosis Procedure

INFOID:0000000005249081

1.

CHECK AWD WARNING LAMP

Perform the trouble diagnosis for AWD warning lamp. Refer to 

DLN-30, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> Check each harness connector pin terminal for malfunction or disconnection.

NO

>> Repair or replace the error-detected parts.