6. Assemble and install the 4C clutch pack (3, 4) into the retainer/bulkhead (13) with the steel separator plate
against the piston.
7. Install the 4C reaction plate (8) and snap-ring (7) into the retainer/bulkhead (13). The 4C reaction plate is non-
directional.
8. Measure the 4C clutch clearance. The correct clutch clearance is 0.770-1.390 mm (0.030-0.055 in.). The snap-
ring (7) is selectable. Install the chosen snap-ring and re-measure to verify the selection.
9. Install the 2C piston (2) into the retainer/bulkhead (13).
10. Position the 2C Belleville spring (5) onto the 2C piston (2).
11. Position the 2C Belleville spring snap-ring (6) onto the 2C Bellevillespring (5).
12. Using Spring Compressor 8249 (2) and a suitable
shop press (1), compress the Belleville spring
until the snap-ring is engaged with the snap-ring
groove in the retainer/bulkhead.
OPERATION
The three input clutches are responsible for driving different components of the planetary geartrain.
UNDERDRIVE CLUTCH
The underdrive clutch is hydraulically applied in first, second, second prime, and third (direct) gears by pressurized
fluid against the underdrive piston. When the underdrive clutch is applied, the underdrive hub drives the input sun
gear.
OVERDRIVE CLUTCH
The overdrive clutch is hydraulically applied in third (direct), fourth,and fifth gears by pressurized fluid against the
overdrive/reverse piston. When the overdrive clutch isapplied, the overdrive hub drives the reverse carrier/input
annulus assembly.
REVERSE CLUTCH
The reverse clutch is hydraulically applied in reverse gear by pressurized fluid against the overdrive/reverse piston.
When the reverse clutch is applied, the reaction annulus gear is driven.
DISASSEMBLY
NOTE: If the input clutch assembly is being reconditioned (clutch/seal replacement) or replaced, it is nec-
essary to perform the Quick Learn Procedure using the scan tool (Refer to 8 -ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL MODULE - STANDARD PROCEDURE).
Theory of Operation
The 3-4 Solenoid is used the engage the gear change form 3rd gear to 4th gear.
The solenoids used in transmission applications are attached to valves which can be classified as normally open or
normally closed. The normally open solenoid valve is defined as a valve which allows hydraulic flow when no cur-
rent or voltage is applied to the solenoid. The normally closed solenoid valve is defined as a valve which does not
allow hydraulic flow when no current or voltage is applied to the solenoid.These valves perform hydraulic control
functions for the transmission and must therefore be durable and tolerantof dirt particles. For these reasons, the
valves have hardened steel poppets and ball valves. The solenoids operatethe valves directly, which means that
the solenoids must have very high outputs to close the valves against the sizable flow areas and line pressures
found in current transmissions. Fastresponse time is also necessary to ensure accurate control.
When Monitored:
Continuously with ignition on.
Set Condition:
This DTC will set if the voltage detected on the 3-4 Shift Solenoid Control circuit at the PCM is different then
the expected voltage. Note: To clear this DTC it is necessary to drive the vehicle at a sustained speed which
would allow the TCC and/or Overdrive Clutch to operate
Possible Causes
TRANSMISSION CONTROL OUTPUT DTC PRESENT
(T9) 3-4 SOLENOID CONTROL CIRCUIT OPEN
(T16) TRANSMISSION CONTROL OUTPUT CIRCUIT OPEN
(T9) 3-4 SOLENOID CONTROL CIRCUIT SHORT TO VOLTAGE
(T9) 3-4 SOLENOID CONTROL CIRCUIT SHORT TO GROUND
(T16) TRANSMISSION RELAY OUTPUT CIRCUIT SHORT TO GROUND
(T9) 3-4 SOLENOID CIRCUIT SHORT TO OTHER CIRCUITS
TOTALLY INTEGRATED POWER MODULE
3-4 SHIFT SOLENOID
POWERTRAIN CONTROL MODULE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
Diagnostic Test
1.CHECK IF THERE ANY TRANSMISSION CONTROL DTCS PRESENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Are there any TIPM TCM Power Control Circuit DTCs also present?
Ye s>>
Refer to the Transmission category, and perform the appropriate symptom(s).
No>>
Go To 2
2.CHECK FOR OTHER TRANSMISSION DTC’S PRESENT
Are there any Park/Neutral or other Transmission DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom(s). If a Park/Neutral DTC is
present, perform its respective test first. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC -
48RE - DIAGNOSIS AND TESTING)
No>>
Go To 3
3.CHECK THE (T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C2 harness connectors.
Disconnect the Transmission Solenoid Assembly harness connector.
Measure the resistance of the (T38) Governor Pressure Sensor Signal
circuit between the Transmission Solenoid Assembly harness connector
and the PCM C2 harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 4
No>>
Repair the (T38) Governor Pressure Sensor Signal circuit
for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
Theory of Operation
The Governor Pressure Sensor is used by the PCM to adjust the Governor Pressure to a desired level for shifts in
first, second, and third gear. If the PCM detects the monitored sense voltage is greater than or less than a prede-
termined specification, the PCM will set the desired DTC.
When Monitored:
Continuously with the ignition on and the engine running.
Set Condition:
This DTC will set if the monitored voltage from the Governor Pressure Sensor drops below 0.12 volts for the
period of 8.5 seconds.
Possible Causes
PARK NEUTRAL DTC PRESENT OR OTHER TRANSMISSION DTC’S PRESENT
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO GROUND
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO OTHER CIRCUITS
TRANSMISSION SOLENOID ASSEMBLY
GOVERNOR PRESSURE SENSOR
POWERTRAIN CONTROL MODULE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
Diagnostic Test
1.CHECK IF THE DTC IS CURRENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Record the Freeze Frame data for the reported DTC.
With the scan tool, erase DTCs.
Turn the ignition off to the lock position.
Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.
NOTE: It may be necessary to road test the vehicle to duplicate the originalset conditions.
With the scan tool, read Engine DTCs.
Did the DTC reset?
Ye s>>
Go To 2
No>>
Go To 7
2.CHECK FOR OTHER TRANSMISSION DTC’S PRESENT
Are there any Park/Neutral or other Transmission DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom(s). If a Park/Neutral DTC is
present, perform its respective test first. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC -
48RE - DIAGNOSIS AND TESTING)
No>>
Go To 3
Theory of Operation
The Transmission Control Output supplies power to the TCC, Overdrive, andGovernor Pressure Solenoids when in
normal operating mode. The Transmission Control Output Control circuit is constantly monitored by the PCM. If the
expected state of the Transmission Control Output Control circuit is different then the expected state, a correspond-
ing DTC will set and the PCM will de-energize the Transmission Control Output and place the transmission in Limp-
in.
When Monitored:
Continuously with the Ignition on.
Set Condition:
This DTC will set if the PCM monitored voltage of the Transmission Control Output Control circuit is different
than the expected voltage for the period 3.0 seconds.
Possible Causes
(T515) TRANSMISSION CONTROL CIRCUIT OPEN
(T515) TRANSMISSION CONTROL CIRCUIT SHORT TO VOLTAGE
(T515) TRANSMISSION CONTROL CIRCUIT SHORT TO GROUND
TOTALLY INTEGRATED POWER MODULE
POWERTRAIN CONTROL MODULE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
1.CHECK IF THE DTC IS CURRENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Record the Freeze Frame data for the reported DTC.
With the scan tool, erase DTCs.
Turn the ignition off to the lock position.
Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.
NOTE: It may be necessary to road test the vehicle to duplicate the originalset conditions.
With the scan tool, read Engine DTCs.
Did the DTC reset?
Ye s>>
Go To 2
No>>
Go To 6
2.CHECK THE (T515) TRANSMISSION CONTROL CIRCUIT
Turn the ignition off to the lock position.
Disconnect the TIPM C1 harness connector.
Ignition on, engine not running.
Using the scan tool in the PCM, actuate the Transmission.
Using a 12-volt test light connected to 12 volts, check the (T515) Trans-
mission Control circuit at the TIPM C1 harness connector.
Does the test light cycle on and off and illuminate brightly?
Ye s>>
Using the schematics as a guide, check the Totally Inte-
grated Power Module (TIPM) pins, terminals, and connec-
tors for corrosion, damage, or terminal push out. Pay
particular attention to all power and ground circuits. If no
2.CHECK FOR OTHER TRANSMISSION DTC’S PRESENT
Are there any Park/Neutral or other Transmission DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom(s). If a Park/Neutral DTC is
present, perform its respective test first.
No>>
Go To 3
3.CHECK THE (T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the ECM C2 harness connectors.
Disconnect the Transmission Solenoid Assembly harness connector.
Measure the resistance of the (T38) Governor Pressure Sensor Signal
circuit between the Transmission Solenoid Assembly harness connector
and the ECM C2 harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 4
No>>
Repair the (T38) Governor Pressure Sensor Signal circuit
for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
4.CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN
Measure the resistance of the (K900) Sensor Ground circuit between
the Transmission Solenoid Assembly harness connector and the ECM
C2 harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the (K900) Sensor Ground circuit for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
Theory of Operation
The Governor Pressure Sensor is used by the ECM to adjust the Governor Pressure to a desired level for shifts in
first, second, and third gear. If the ECM detects the monitored sense voltage is greater than or less than a prede-
termined specification, the ECM will set the desired DTC.
When Monitored:
Continuously with the ignition on and the engine running.
Set Condition:
This DTC will set if the monitored voltage from the Governor Pressure Sensor drops below 0.12 volts for the
period of 8.5 seconds.
Possible Causes
PARK NEUTRAL DTC PRESENT OR OTHER TRANSMISSION DTC’S PRESENT
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO GROUND
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO OTHER CIRCUITS
TRANSMISSION SOLENOID ASSEMBLY
GOVERNOR PRESSURE SENSOR
ENGINE CONTROL MODULE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
Diagnostic Test
1.CHECK IF THE DTC IS CURRENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Record the Freeze Frame data for the reported DTC.
With the scan tool, erase DTCs.
Turn the ignition off to the lock position.
Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.
NOTE: It may be necessary to road test the vehicle to duplicate the originalset conditions.
With the scan tool, read Engine DTCs.
Did the DTC reset?
Ye s>>
Go To 2
No>>
Go To 7
2.CHECK FOR OTHER TRANSMISSION DTC’S PRESENT
Are there any Park/Neutral or other Transmission DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom(s). If a Park/Neutral DTC is
present, perform its respective test first.
No>>
Go To 3