Automatic Disconnecting Differential Control System: Inspection

INSPECT A.D.D. ACTUATOR
1. Disconnect the actuator connector.
2. Measure the resistance between the terminals 2 and 6.
  Standard resistance: 0.3-100 Ω.
3. Measure the resistance between the terminals 2 or 6 and body ground.
  Standard resistance: More than 0.5 MΩ.
If the resistance value is not as specified, replace the actuator assembly.

Fig 1: Identifying Actuator Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT A.D.D. ACTUATOR OPERATION

Apply battery positive voltage between the terminal 2 or 6, and check the actuator operation by sound, A.D.D. status and continuity between the terminal 3 and 4.

TERMINAL VOLTAGE CHART

Battery voltage applied terminal	3-4 terminals continuity	A.D.D status
2 (+) - 6 (-)	Continuity	Connected
2 (-) - 6 (+)	No continuity	Disconnected

If the operation is not as specified, replace the actuator assembly.

INSPECT LIMIT SWITCH CONTINUITY

Connect the actuator connector.
Shift the transfer shift lever "H" position and switch the 2-4 selector switch OFF.
Check the A.D.D. actuator operation by sound.
Disconnect the actuator connector.

Check the continuity between each terminal, as shown in the chart.

TERMINAL CONTINUITY CHART

Tester Connected Terminal Number	Specified Condition
1-3	Continuity
1-4	No Continuity
3-5	No Continuity
4-5	No Continuity

Fig 2: Inspecting Limit Switch Continuity

Connect the actuator connector.
Shift the transfer shift lever "H" position and switch the 2 - 4 selector switch ON.

Fig 3: Moving Shift Lever And Selector Switch To Proper Positions
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Check the A.D.D. actuator operation by sound.
Disconnect the actuator connector.

Check the continuity between each terminal, as shown in the chart.

TERMINAL CONTINUITY CHART

Tester Connected Terminal Number	Specified Condition
1-3	No continuity
1-4	No continuity
3-5	Continuity
4-5	No continuity

Connect the actuator connector.

INSPECT TRANSFER 4WD POSITION SWITCH (See COMPONENTS )
REMOVE A.D.D. ACTUATOR (See DISASSEMBLY )
INSPECT CLUTCH HUB AND CLUTCH SLEEVE
1. Check the clutch hub and clutch sleeve for wear and damage.
  If necessary, replace them.
2. Check that clutch sleeve slides smoothly on the clutch hub.
  
  Fig 4: Checking Clutch Sleeve Slides Smoothly On Clutch Hub
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
MEASURE SLEEVE FORK AND CLUTCH SLEEVE CLEARANCE
Using a feeler gauge, measure the clearance between the sleeve fork and clutch sleeve.

Maximum clearance: 0.35 mm (0.0138 in.)

If the clearance exceeds the maximum, replace the fork or sleeve.

Fig 5: Measuring Clearance Between Sleeve Fork And Clutch Sleeve
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002