TRANSFER CONTROL UNITDLN-85
< ECU DIAGNOSIS > [ATX14B]
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PHYSICAL VALUES
Terminal Layout
SHIFT AC MON2 [ON/
OFF] Check signal for transfer
control unit signal output • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 4LO to
4H (Wait function is oper-
ating.)
ON
Except the above OFF
T/F F SPEED [km/h] or
[mph] Displayed, but do not use.
AT R SPEED [km/h] or
[mph] Condition of vehicle
speed sensor A/T (output
speed sensor)
During driving Approximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5] Condition of A/T selector
lever position
Displays actual A/T gear position. 1
2
3
4
5
Monitored item [Unit]
Content ConditionDisplay value
WDIA0378E
Te r m i n a lWire
color Item
ConditionData (Approx.)
1 GR 2-4WD shift solenoid valve • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: 2WD
0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
2 B/W 4WD shift indicator lamp
(2WD indicator lamp) 2WD indicator lamp: OFF
Battery voltage
2WD indicator lamp: ON 0V
3 B Ground Always0V
4 Y/L Transfer shift high relay • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed 4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
5 W/B 4WD warning lamp 4WD warning lamp: ON
0V
4WD warning lamp: OFF Battery voltage
6 B Ground Always0V
7 L CAN-H ——
8 P CAN-L ——
9G/W 4WD shift switch
(2WD) Ignition switch: ON4WD shift switch: 2WD
Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V
Revision: April 20092010 QX56
DLN-86
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
10 L/W Transfer dropping resistor• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: AUTO
4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
11 L 4WD shift indicator lamp
(Lock indicator lamp) Lock indicator lamp of 4WD shift indicator lamp: OFF
Battery voltage
Lock indicator lamp of 4WD shift indicator lamp: ON 0V
12 W/G 4LO indicator lamp 4LO indicator lamp: OFF
Battery voltage
4LO indicator lamp: ON 0V
13 G/B Transfer shift low relay • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed 4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
14 LG Transfer motor relay • Accelerator pedal
depressed
• Vehicle stopped
• Engine running
• Brake pedal de- pressed 4WD shift switch: 2WD
Battery voltage
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position) Battery voltage
(0V for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position) 0V
4WD shift switch: 4H (A/T selector lever
“P” position) Battery voltage
(0V for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position) 0V
15 L/B ATP warning lamp ATP indicator lamp: ON
0V
ATP indicator lamp: OFF Battery voltage
16 Y/R Power supply Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
18 O 4WD shift switch
(4H) Ignition switch: ON4WD shift switch: 4H
Battery voltage
4WD shift switch: 2WD, AUTO or 4LO 0V
19 L Clutch pressure solenoid
valve • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: AUTO
1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
21 BR 4WD shift indicator lamp
(AUTO indicator lamp) • AUTO indicator lamp of 4WD shift indicator lamp: OFF
Battery voltage
AUTO indicator lamp of 4WD shift indicator lamp: ON 0V
22 Y/R Power supply Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
23 R 4WD shift switch
(4LO)
Ignition switch: ON4WD shift switch: 4LO
Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 LG/R 4WD shift switch
(AUTO)
Ignition switch: ON4WD shift switch: AUTO
Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V
Te r m i n a l
Wire
color Item
ConditionData (Approx.)
Revision: April 20092010 QX56
DLN-102
< SYMPTOM DIAGNOSIS >[ATX14B]
4WD SYSTEM SYMPTOMS
SYMPTOM DIAGNOSIS
4WD SYSTEM SYMPTOMS
Symptom TableINFOID:0000000005148856
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to DLN-18, "CONSULT-III Function (ALL MODE AWD/4WD)".
NOTE:
• Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not a
malfunction.
• Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift
switch is 4H or 4LO, steering wheel is turned fully to either side.
Symptom ConditionReference page
4WD shift indicator lamp and 4LO indicator lamp do not turn ON
(4WD shift indicator lamp and 4LO indicator lamp check) Ignition switch: ON
DLN-103
4WD warning lamp does not turn ON
(4WD warning lamp check) Ignition switch: ON
DLN-105
4WD shift indicator lamp or 4LO indicator lamp does not change Engine runningDLN-107
ATP warning lamp does not turn ON Engine runningDLN-109
4WD shift indicator lamp keeps flashing Engine runningDLN-111
4WD warning lamp flashes rapidly (2 times/second) While drivingDLN-112
4WD warning lamp flashes slowly
(1 time/2 seconds) While driving
DLN-113
Heavy tight-corner braking symptom occurs
(See NOTE.) • While driving
•AUTO mode
• Steering wheel is turned fully
to either side DLN-114
ATP switch does not operate
Engine runningDLN-116
4WD system does not operate While drivingDLN-118
Revision: April 20092010 QX56
4WD WARNING LAMP DOES NOT TURN ONDLN-105
< SYMPTOM DIAGNOSIS > [ATX14B]
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4WD WARNING LAMP DOES NOT TURN ON
DescriptionINFOID:0000000005148859
4WD warning lamp does not turn ON when turning ignition switch to ON.
Diagnosis ProcedureINFOID:0000000005148860
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK TRANSFER CONTROL UNIT POWER SUPPLY AND GROUND CIRCUITS
Refer to DLN-22, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair as necessary.
2.CHECK COMBINATION METER POWER SUPPLY AND GROUND CIRCUITS
Refer to MWI-28, "
COMBINATION METER : Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Perform repairs as necessary.
3.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit and combination meter harness connectors.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (A) terminal 5 and combination meter harness connector M23 (B) terminal 49.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Turn ignition switch ON. (Do not start engine.)
3. Ground the following terminal using suitable wiring.
- Transfer control unit harness connector E142 terminal 5 and ground.
Does 4WD warning lamp turn on?
YES >> GO TO 5.
NO >> Replace combination meter. Refer to MWI-100,
"Removal and Installation".
5.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End. Continuity should exist.
AWDIA0187ZZ
SDIA2774E
Revision: April 20092010 QX56
DLN-106
< SYMPTOM DIAGNOSIS >[ATX14B]
4WD WARNING LAMP DOES NOT TURN ON
NO >> GO TO 6.
6.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> Inspection End.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
Revision: April 20092010 QX56
ATP WARNING LAMP DOES NOT TURN ONDLN-109
< SYMPTOM DIAGNOSIS > [ATX14B]
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ATP WARNING LAMP DOES NOT TURN ON
DescriptionINFOID:0000000005148863
ATP warning lamp does not turn ON when the transfer case is switched in or out of 4LO with the A/T selector
lever in N position.
Diagnosis ProcedureINFOID:0000000005148864
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to DLN-18, "
CONSULT-III Function (ALL MODE AWD/4WD)".
Do the self-diagnostic results indicate CAN communication?
YES >> Perform trouble diagnosis for CAN communication line.
NO >> GO TO 2.
2.CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to DLN-32, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK SYSTEM FOR TRANSMIS SION RANGE SWITCH SIGNAL
Perform trouble diagnosis for transmission range switch signal system. Refer to DLN-39, "
Diagnosis Proce-
dure".
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK SYSTEM FOR ATP SWITCH
Perform trouble diagnosis for ATP switch system. Refer to DLN-116, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and combination meter harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (B) terminal 15 and combination meter harness connector M23 (A) terminal 43.
Continuity should exist.
AWDIA0185ZZ
Revision: April 20092010 QX56
DLN-110
< SYMPTOM DIAGNOSIS >[ATX14B]
ATP WARNING LAMP DOES NOT TURN ON
- Transfer control unit harness
connector E143 (B) terminal 40
and combination meter harness connector M23 (A) terminal 44.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 6.
NO >> Repair or replace damaged parts.
6.CHECK ATP WARNING LAMP CIRCUIT
1. Place A/T selector lever in P position.
2. Connect combination meter harness connector and transfer control unit harness connector.
3. Disconnect ATP switch harness connector.
4. Ground the following terminal using suitable wiring.
- ATP switch harness connector F55 terminal 8 and ground.
5. Turn ignition switch ON. (Do not start engine.)
Does indicator lamp turn on?
YES >> GO TO 7.
NO >> Replace combination meter. Refer to MWI-100,
"Removal and Installation".
7.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End.
NO >> GO TO 8.
8.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 9.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
9.CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to DLN-142, "
Disassembly and Assembly".
2. Check transfer inner parts.
Are the inspection results normal?
YES >> Inspection End.
NO >> Repair or replace damaged parts. 40 to 44: Continuity should not exist.
44 to 40: Continuity should exist.
AWDIA0186ZZ
SDIA2769E
Revision: April 20092010 QX56
DLN-112
< SYMPTOM DIAGNOSIS >[ATX14B]
4WD WARNING LAMP FLASHES RAPIDLY
4WD WARNING LAMP FLASHES RAPIDLY
DescriptionINFOID:0000000005148867
The 4WD warning lamp flashes quickly while driving (2 times / second). The lamp continues to flash until the
ignition switch is turned OFF.
Diagnosis ProcedureINFOID:0000000005148868
1.CHECK TIRE
Check the following.
• Tire pressure
• Wear condition
• Longitudinal tire size (There is no difference between longitudinal tires.)
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair or replace damaged parts.
2.CHECK 4WD WARNING LAMP
Stop the vehicle and allow it to idle for a short period of time.
Does flashing stop?
YES >> Inspection End.
NO >> GO TO 3.
3.CHECK TRANSFER FLUID TEMPERATURE
Perform trouble diagnosis for transfer fluid temperature system. Refer to DLN-68, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End.
NO >> GO TO 5.
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> Inspection End.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
Revision: April 20092010 QX56