4. Remove timing valve cover.
5. Remove 3-4 timing valve and spring.
6. Remove 3-4 quick fill valve, spring and plug.
7. Remove 3-4 shift valve and spring.
8. Remove converter clutch valve, spring and plug.
9. Remove converter clutch timing valve, retainer and
valve spring.
CLEANING
Clean the valve housings, valves, plugs, springs, and separator plates with a standard parts cleaning solution only.
Do not use gasoline, kerosene, or any type of caustic solution.
Do not immerse any of the electrical components in cleaning solution. Clean the governor solenoid and sensor and
the dual solenoid and harness assembly by wiping them off with dry shop towels only.
Dry all except the electrical parts with compressed air. Make sure all passages are clean and free from obstructions.
Do not use rags or shop towels to dry or wipe off valve body components. Lint from these materials can
stick to valve body parts, interfere with valve operation, and clog filters and fluid passages.
Wipe the governor pressure sensor and solenoid valve with dry, lint free shop towels only. The O-rings on the sen-
sor and solenoid valve are the only serviceable components. Be sure the vent ports in the solenoid valve are open
and not blocked by dirt or debris. Replace the valve and/or sensor only whenDRB scan tool diagnosis indicates this
is necessary. Or, if either part has sustained physical damage (dented, deformed, broken, etc.).
CAUTION: Do not turn the small screw at the end of the solenoid valve for any reason. Turning the screw
in either direction will ruin solenoid calibration and result in solenoidfailure. In addition, the filter on the
solenoid valve is NOT serviceable. Do not try to remove the filter as this will damage the valve housing.
INSPECTION
Inspect the throttle and manual valve levers and shafts. Do not attempt to straighten a bent shaft or correct a loose
lever. Replace these components if worn, bent, loose or damaged in any way.
Inspect all of the valve body mating surfaces for scratches, nicks, burrs,or distortion. Use a straightedge to check
surface flatness. Minor scratches may be removed with crocus cloth using only very light pressure.
Minor distortion of a valve body mating surface may be corrected by smoothing the surface with a sheet of crocus
cloth. Position the crocus cloth on a surface plate, sheet of plate glass orequally flat surface. If distortion is severe
or any surfaces are heavily scored, the valve body will have to be replaced.
CAUTION: Many of the valves and plugs, such as the throttle valve, shuttle valve plug, 1-2 shift valve and
1-2 governor plug, are made of coated aluminum. Aluminum components are identified by the dark color of
thespecialcoatingappliedtothesurface(orbytestingwithamagnet).Donot sand aluminum valves or
plugs under any circumstances. This practice could damage the special coating causing the valves/plugs to
stick and bind.
Inspect the valves and plugs for scratches, burrs, nicks, or scores. Minorsurface scratches on steel valves and
plugs can be removed with crocus cloth butdo not round off the edges of the valve or plug lands.Maintaining
sharpness of these edges is vitally important. The edges prevent foreign matter from lodging between the valves
and plugs and the bore.
Inspect all the valve and plug bores in the valve body. Use a penlight to viewthe bore interiors. Replace the valve
body if any bores are distorted or scored. Inspect all of the valve body springs. The springs must be free of dis-
tortion, warpage or broken coils.
Check the two separator plates for distortion or damage of any kind. Inspect the upper housing, lower housing, 3-4
accumulator housing, and transfer plate carefully. Be sure all fluid passages are clean and clear. Check condition of
the upper housing and transfer plate check balls as well. The check balls and ball seats must not be worn or dam-
aged.
Trial fit each valve and plug in its bore to check freedom of operation. Whenclean and dry, the valves and plugs
shoulddropfreelyintothebores.
Valve body bores do not change dimensionally with use. If the valve body functioned correctly when new, it will
continue to operate properly after cleaning and inspection. It should notbe necessary to replace a valve body
assembly unless it is damaged in handling.
The only serviceable valve body components are listed below. The remaining valve body components are serviced
only as part of a complete valve body assembly. Serviceable parts are:
dual solenoid and harness assembly
solenoid gasket
solenoid case connector O-rings and shoulder bolt
switch valve and spring
pressure adjusting screw and bracket assembly
throttle lever
manual lever and shaft seal
throttle lever shaft seal, washer, and E-clip
fluid filter and screws
detent ball and spring
valve body screws
governor pressure solenoid
governor pressure sensor and retaining clip
park lock rod and E-clip
ASSEMBLY
CAUTION: Do not force valves or plugs into place during reassembly. If the valve body bores, valves and
plugs are free of distortion or burrs, the valve body components should allslide into place easily. In addi-
tion, do not overtighten the transfer plate and valve body screws during reassembly. Overtightening can
distort the housings resulting in valve sticking, cross leakage and unsatisfactory operation. Tighten valve
body screws to recommended torque only.
7. Lubricate solenoid case connector (1) O-rings and
shaft of manual lever with light coat of petroleum
jelly.
8. Attach solenoid case connector to 3-4 accumulator
with shoulder-type screw. Connector has small
locating tang that fits indimple at top of accumula-
tor housing (2). Seat tang in dimple before tighten-
ing connector screw.
9. Install solenoid assembly and gasket. Tighten sole-
noid attaching screws to 8 Nꞏm (72 in. lbs.) torque.
10. Verify that solenoid wire harness is properly
routed. Solenoid harness must be clear of manual
lever and park rod and not be pinched between
accumulator housing and cover.
11. Position line pressure adjusting screw in adjusting
screw bracket.
12. Install switch valve spring on tang at end of
adjusting screw bracket.
13. Position adjusting screw bracket on valve body.
Align valve springs and press bracket into place.
Install short, upper bracket screws first and long
bottom screw last. Verify that valve springs and
bracket are properly aligned. Then tighten all
three bracket screws to 4 Nꞏm (35 in. lbs.) torque.
14. Perform Line Pressure and Throttle Pressure
adjustments. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC/VALVE BODY - ADJUSTMENTS)
GOVERNOR BODY, SENSOR AND SOLENOID
1. Turn valve body assembly over so accumulator side of transfer plate is facing down.
2. Install new O-rings on governor pressure solenoid and sensor.
3. Lubricate solenoid and sensor O-rings with clean transmission fluid.
4. Install governor pressure sensor in governor body.
5. Install governor pressure solenoid in governor body. Push solenoid in until it snaps into place in body.
6. Position governor body gasket on transfer plate.
7. Install retainer plate on governor body and around solenoid. Be sure solenoid connector is positioned in retainer
cutout.
8. Align screw holes in governor body and transfer plate. Then install and tighten governor body screws to 4 Nꞏm
(35 in. lbs.) torque.
9. Connect harness wires to governor pressure solenoid and governor pressure sensor.
10. Install fluid filter and pan.
11. Lower vehicle.
12. Fill transmission with recommended fluid and road test vehicle to verify repair.
3.ACTUATE T-CASE MOTOR
Reconnect the TIPM C4 harness connector.
Ignition on, engine not running.
With the scan tool, actuate the T-Case Motor Brake.
Using a 12-volt test light connected to 12-volts, check the (T300) Trans-
fer Case Motor Brake Signal circuit at the Shift Motor/Mode Sensor
Assembly harness connector.
NOTE: Compare the brightness to that of a direct connection to
the battery.
Does the test light illuminate brightly?
Ye s>>
Replace the Totally Integrated Power Module (TIPM) in
accordance with the Service Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go to 4
4.(T300) TRANSFER CASE MOTOR BRAKE SIGNAL CIRCUIT OPEN
Turn the ignition off to the lock position.
Disconnect the TIPM C4 harness connector.
Measure the resistance of the (T300) Transfer Case Motor Brake Signal
circuit between the TIPM C4 harness connector and the Shift Motor/
Mode Sensor Assembly harness connector.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T300) Transfer Case Motor Brake Signal circuit
for an open circuit or high resistance.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Replace the Totally Integrated Power Module (TIPM) in
accordance with the Service Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
5.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Were any problems found?
Ye s>>
Repair as necessary.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)
No>>
Te s t c o m p l e t e .
When Monitored:
The ignition on, with the T-Case Switch in a 4W/LO position.
Set Condition:
The TIPM detects the Front Axle Lock Control circuit is shorted low.
Possible Causes
(G304) FRONT AXLE LOCK CONTROL CIRCUIT SHORTED TO GROUND
FRONT AXLE DISCONNECT (FAD) MODULE
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.ACTIVE DTC
CAUTION: Before removing the TIPM harness connectors, clean the connector and locking cam area of dirt
and debris. Failure to do so can result in the connector being jammed or damage to the locking cams on
the harness connector or module. Do not force the assist arm when releasingor installing the harness con-
nector.
Ignition on, engine not running.
With the scan tool, read the TIPM DTCs.
Is the status Active for this DTC?
Ye s>>
Go To 2
No>>
Go To 6
2.(G304) FRONT AXLE LOCK CONTROL CIRCUIT
Turn the ignition off to the lock position.
Disconnect the FAD harness connector.
Ignition on, engine not running.
With the scan tool, actuate the Front Axle Lock Control in the TIPM.
Using a 12-volt test light connected to 12-volts, check the (G304) Front Axle Lock Control circuit in the FAD harness
connector.
Does the test light illuminate brightly?
Ye s>>
Go To 5
No>>
Go To 3
When Monitored:
The ignition on, with the T-Case Switch in 4W/LO position.
Set Condition:
The TIPM detects the Front Axle Lock Signal circuit is shorted low.
Possible Causes
(A880) FUSED B+ CIRCUIT OPEN
(G303) FRONT AXLE LOCK SIGNAL CIRCUIT OPEN
(G304) FRONT AXLE LOCK CONTROL CIRCUIT OPEN
FRONT AXLE DISCONNECT (FAD) MODULE
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.ACTIVE DTC
CAUTION: Before removing the TIPM harness connectors, clean the connector and locking cam area of dirt
and debris. Failure to do so can result in the connector being jammed or damage to the locking cams on
the harness connector or module. Do not force the assist arm when releasingor installing the harness con-
nector.
Ignition on, engine not running.
With the scan tool, read the TIPM DTCs.
Is the DTC currently active?
Ye s>>
Go To 2
No>>
Go To 6
2.(A880) FUSED B+ OPEN
Turn the ignition off to the lock position.
Disconnect the FAD harness connector.
Ignition on, engine not running.
With the scan tool, actuate the Front Axle Lock in the TIPM.
Using a 12-volt test light connected to ground, check the (A880) Front
Axle Lock Signal circuit in the FAD harness connector.
NOTE: The test light must illuminate brightly. Compare the bright-
ness to that of a direct connection to the battery.
Does the test light illuminate brightly?
Ye s>>
Go To 3
No>>
Repair the (A880) Fused B+ circuit for an open.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
3.(G304) FRONT AXLE LOCK CONTROL CIRCUIT
Using a 12-volt test light, jump across from the (A880) Fused B+ circuit
and the G304 Front Axle Lock Control circuit in the FAD harness con-
nector.
With the scan tool, actuate the Front Axle Lock in the TIPM.
Does the test light illuminate brightly and flash on and off?
Ye s>>
Go To 4
No>>
Go To 6
4.(G303) FRONT AXLE LOCK SIGNAL CIRCUIT
Turn the ignition off to the lock position.
Reconnect the FAD harness connector.
Using a 12-volt test light connected to ground, backprobe the (G303)
Front Axle Lock Signal circuit in the TIPM C4 harness connector.
Ignition on, engine not running.
With the scan tool, actuate the Front Axle Lock in the TIPM.
Does the test light illuminate brightly?
Ye s>>
Go To 8
No>>
Go To 5
3.(G304) FRONT AXLE LOCK CONTROL CIRCUIT
Turn the ignition off to the lock position.
Disconnect the TIPM C2 harness connector.
Ignition on, engine not running.
With the scan tool, actuate the TIPM.
Using a 12-volt test light connected to 12-volts, check the (G304) Front Axle Lock Control circuit in the FAD harness
connector.
Does the test light turn on and off?
Ye s>>
Go To 5
No>>
Go To 4
4.(G304) FRONT AXLE LOCK CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off to the lock position.
Measure the resistance between ground and the (G304) Front Axle
Lock Control circuit in the TIPM C2 harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (G304) Front Axle Lock Control circuit for a short
to ground.
Perform the TRANSFER CASE VERIFICATION TEST-VER
1. (Refer to 21 - TRANSMISSION/TRANSAXLE/TRANSFER
CASE - STANDARD PROCEDURE)
No>>
Go To 4
5.TOTALLY INTEGRATED POWER MODULE (TIPM)
Using the wiring diagram/schematic as a guide, inspect all wiring and connectors that pertain to this circuit.
Were any problems found?
Ye s>>
Repair as necessary.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)
No>>
Replace the Totally Integrated Power Module (TIPM) in accordance with theService Information.
Perform the TRANSFER CASE VERIFICATION TEST-VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - STANDARD PROCEDURE)