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Locking Hubs - Automatic Free-Wheeling: Other Mazda MPV I

Locking Hubs 8 illustrations ~1003 words

Lock To Free-Wheeling (4WD To 2WD)

  1. Faulty AFW Main Switch
  2. Faulty Lock Solenoid
  3. Faulty Vacuum Actuator
  4. Vacuum Leak At Actuator Or Reservoir
  5. Faulty One-Way Check Valve

HEAT BUILD-UP

  1. Low Front Differential Fluid Level
  2. Incorrect Shaft End Play
  3. Incorrect Gear End Play
  4. Excessive Fluid In Front Differential

OIL LEAKS

  1. Excessive Fluid In Front Differential
  2. Loose AFW Assembly Mounting Bolts
  3. Worn Or Damaged Oil Seal

Fail Mode Function

A warning alarm will sound approximately 5 times in 8 seconds if a malfunction occurs in change motor or electrical circuit. If malfunction is indicated, inspect change motor and circuit. Repair or replace as necessary.

Note. While in fail mode, a warning alarm (same as above) will sound each time 4WD/2WD shift switch and center differential lock switch are activated.

  1. Fail mode function is canceled when ignition is turned off.
  2. If a malfunction of either position switch occurs in change motor while it is operating, 4WD control unit selects 2WD mode.
  3. If a malfunction of either limit switch occurs while shifting, 4WD control unit sets motor stop position.

Caution Mode Function

A caution alarm will sound 3 times if4WD/2WD shift switch is activated while driving in 4WD LOCK mode (center differential lock switch activated). Proper sequence is to deactivate center differential lock switch (placing system in 4WD FREE mode), then set 4WD/2WD shift switch to 2WD mode.

CHANGE MOTOR

Remove change motor from transaxle. See CHANGE MOTOR under REMOVAL & INSTALLATION. Connect positive lead of battery to terminal 2A of change motor connector and negative lead to terminal 2B. (Scheme 16) Ensure motor rotates clockwise. Reverse battery leads on change motor connector terminals. Motor should rotate counterclockwise. If change motor does not operate as specified, replace motor.

Scheme 16

Scheme 16: CHANGE MOTOR
Scheme 16: CHANGE MOTOR

CHANGE MOTOR LIMIT SWITCH

  1. Remove change motor from transaxle. See CHANGE MOTOR under REMOVAL & INSTALLATION. Secure change motor in vise. Using ohmmeter, ensure continuity is not present between change motor limit switch connector terminals "F" and "H". (Scheme 17)
  2. Using Change Motor Adapter (49-L017-302), rotate change motor shaft clockwise until continuity is present between change motor limit switch connector terminals "F" and "H". Allow shaft to turn counterclockwise and note torque when continuity is lost. Torque should be 22-43 INCH lbs. (2.5-4.9 N.m).
  3. Rotate shaft counterclockwise as in step 2) and check continuity and torque reading. Using ohmmeter, ensure continuity is not present between change motor limit switch connector terminals "E" and "H". (Scheme 17)
  4. Using change motor adapter, rotate change motor shaft clockwise until continuity is present between change motor limit switch connector terminals "E" and "H". Allow shaft to turn counterclockwise and note torque when continuity is lost. Torque should be 61-113 INCH lbs. (6.9-13 N.m).
  5. Rotate shaft counterclockwise as in step 4) and check continuity and torque reading. If torque and continuity are not as specified in step 4), replace change motor.

Scheme 17

Scheme 17
Scheme 17

CHANGE MOTOR POSITION SWITCH

  1. Remove change motor from transaxle. See CHANGE MOTOR under REMOVAL & INSTALLATION. Connect ohmmeter between terminals "A" and "D" of change motor position switch connector. (Scheme 18) Connect positive lead of battery to terminal 2A of change motor connector and negative lead to terminal 2B. (Scheme 18) Rotate change motor one revolution and check for continuity. Continuity should be present.
  2. Move ohmmeter leads to terminals "B" and "D". Rotate change motor as in step 1). Continuity should be present. Move ohmmeter leads to terminals "C" and "D". Again, rotate change motor as instep 1). Continuity should be present. If continuity is not as specified, replace change motor.

Scheme 18

Scheme 18
Scheme 18

CHANGE MOTOR RELAYS

  1. Remove change motor relay(s). Relays are located on right side of firewall, in engine compartment. (Scheme 19) Using ohmmeter, ensure continuity is present between change motor relay terminals "A" and "B", and terminals "C" and "F". (Scheme 19)
  2. Connect positive lead of battery to terminal "A" of change motor relay and negative lead to terminal "B". (Scheme 19) Using ohmmeter, ensure continuity is present between change motor relay terminals "C" and "E". If continuity is not present, replace relay.

Scheme 19

Scheme 19
Scheme 19

CHECK VALVE

Check valve is located in hose from intake manifold to vacuum reservoir. Remove check valve. Blow air through each side of check valve. Air should hold only on side toward reservoir. Replace check valve if air does not hold.

CONTROL BOX SWITCH

Disconnect negative battery cable. Raise and support vehicle. Disconnect and remove electrical switch from control box. Check continuity of switch. (Scheme 20) Continuity should be present when switch is depressed. Continuity should not be present when switch is released. If continuity is not as specified, replace switch.

Scheme 20

Scheme 20: CONTROL BOX SWITCH
Scheme 20: CONTROL BOX SWITCH

SOLENOID VALVES

Free and lock solenoids are identical. Disconnect vacuum hoses and electrical connectors from solenoid valve. Blow through port "B" and verify air flows from air filter outlet of solenoid. (Scheme 21) Connect a 12-volt power source and ground to each solenoid. Blow through port "B" and verify air flows from port "A". If solenoid does not operate as specified, replace solenoid.

Scheme 21

Scheme 21: SOLENOID VALVES
Scheme 21: SOLENOID VALVES

VACUUM ACTUATOR

Raise and support vehicle. Disconnect vacuum hoses from actuator. Connect a hand vacuum pump to "free" side of actuator. Apply 8 in. Hg and ensure actuator rod moves inward. Disconnect vacuum pump. Connect hand vacuum pump to "lock" side of actuator. Apply 8 in. Hg and ensure actuator rod moves outward. If actuator rod does not operate as specified, replace actuator.

VACUUM RESERVOIR

Raise and support vehicle. Disconnect vacuum hoses from AFW reservoir, mounted on firewall in engine compartment. Plug one fitting on reservoir. Connect a hand vacuum pump to other fitting and apply 28 in. Hg. Replace reservoir if it does not hold vacuum.

4WD CONTROL UNIT

Remove "B" pillar trim panel behind driver's seat, and locate control unit and connector. Turn ignition on. Measure pin voltages at control unit connector. (Scheme 21)and see scheme 12. If voltage is not as specified, check system wiring circuits. If wiring circuits are okay, replace faulty component or control unit with a known good unit.

Scheme 22

Scheme 22: 4WD CONTROL UNIT
Scheme 22: 4WD CONTROL UNIT

Scheme 23

Scheme 23
Scheme 23

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