9.CHECK THE 5 VOLT SUPPLY CIRCUIT FOR AN OPEN INSIDE THE TRANSMISSION
Reconnect the Transmission Solenoid Assembly harness connector.
Remove the transmission oil pan per the Service Information. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/FLUID -
STANDARD PROCEDURE)
Disconnect the Governor Pressure Sensor connector internal to the
transmission.
Measure the resistance of the 5-volt Supply circuit between the ECM
C2 harness connector and the Transmission Solenoid Assembly con-
nector internal to the transmission.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 10
No>>
Repair or replace the 5-volt Supply circuit for an open inter-
nal to the transmission.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
10.CHECK THE ENGINE CONTROL MODULE - 5 VOLT SUPPLY
Reconnect the ECM harness connectors.
Ignition on, engine not running.
Measure the voltage of the 5-volt Supply circuit in the Governor Pres-
sure Sensor connector internal to the transmission.
Is the voltage between 4.5 and 5.5 volts?
Ye s>>
Replace the Governor Pressure Sensor per the Service
Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE/GOVERNOR PRESSURE SENSOR -
REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Using the schematics as a guide, check the Engine Control
Module (ECM) pins, terminals, and connectors for corrosion,
damage, or terminal push out. Pay particular attention to all
power and ground circuits. If no problems are found,
replace and program the ECM per the Service Information.
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/ENGINE CONTROL MODULE - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
Theory of Operation
The Governor Pressure Sensors output is used as a control input to the Governor Pressure Control System. The
Governor Pressure Control System is used to regulate the governor pressure which controls the shifts for first, sec-
ond, and third gear.
When Monitored:
While the engine is running and the vehicle gear selector is in park or neutral for more than 3.0 seconds with
the throttle position less than 10%.
Set Condition:
This DTC will set if the Governor Pressure is greater than 3 psi while the vehicle is in Park 3 times in a drive
cycle.
Possible Causes
OTHER TRANSMISSION DTCS PRESENT
5 VOLT SUPPLY CIRCUIT OPEN - EXTERNAL
5 VOLT SUPPLY CIRCUIT OPEN - INTERNAL
GOVERNOR PRESSURE SENSOR
TRANSMISSION - INTERNAL DAMAGE
TRANSMISSION - INTERNAL LEAK
ENGINE CONTROL MODULE
INTERMITTENT WIRING AND CONNECTORS
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
Diagnostic Test
1.OTHER TRANSMISSION DTCS PRESENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Are any other transmission DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom(s).
No>>
Go To 2
2.CHECK IF THE GOVERNOR PRESSURE IS ABOVE 21 KPA (3 PSI) IN PARK
CAUTION: Apply the parking brake.
Start the engine and allow the engine to idle.
Warm the transmission to a normal operating temperature above 43° C (110° F).
With the scan tool in Sensors, read the Governor Pressure with the Transmission Shift selector in Park.
Is the Governor Pressure reading on the scan tool above 21 kPa or 3 psi?
Ye s>>
Go To 3
No>>
Go To 10
3.COMPARE SCAN TOOL GOVERNOR PRESSURE READING TO PRESSURE GAUGE READING
Turn the ignition off to the lock position.
Connect a 700 kPa (100 psi) Pressure Gauge to the Governor Pressure test port. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - DIAGNOSIS AND TESTING)
Start the engine and allow the engine to idle.
Warm the transmission to a normal operating temperature above 43° C (110° F).
With the scan tool, read the Governor Pressure and compare the scan tool Governor Pressure reading to the Pres-
sure Gauge reading.
Does the scan tool Governor Pressure reading match the Pressure Gauge reading within 6.9 kPa (1
psi)?
Ye s>>
Go To 4
No>>
Go To 7
4.TRANSMISSION - INTERNAL DAMAGE
Turn the ignition off to the lock position.
Remove the transmission oil pan per the Service Information. (Refer to 21 -TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 48RE/FLUID - STANDARD PROCEDURE)
Inspect the transmission oil pan for burnt oil and/or excessive debris.
Does the transmission contain burnt oil and/or excessive debris?
Ye s>>
Repair internal transmission as necessary. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC -
48RE - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 5
5.CHECK INTERNAL TRANSMISSION FOR A FLUID LEAK
Inspect the transmission for internal fluid leakage in the Valve Body or the Governor Pressure Solenoid. (Refer to 21
- TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL)
Were there any problems found?
Ye s>>
Repair the internal transmission as necessary per the Service Information. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 6
6.VERIFY OPERATION - TEST DRIVE
Remove the pressure gauge from the transmission.
Install the transmission oil pan and refill the transmission per the Service Information. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE/FLUID - STANDARD PROCEDURE)
With the scan tool, erase Engine DTCs.
Test drive the vehicle.
Be sure to stop the vehicle and move the gear selector into the park positionfor a minimum of 5 seconds at least
three times during the drive cycle.
With the scan tool, read Engine DTCs.
Did the DTC reset?
Ye s>>
Using the schematics as a guide, check the Engine Control Module (ECM) pins, terminals, and connec-
tors for corrosion, damage, or terminal push out. Pay particular attentiontoallpowerandgroundcir-
cuits. If no problems are found, replace and program the ECM per the ServiceInformation. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 10
7.CHECK THE 5 VOLT SUPPLY CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the ECM C2 harness connector.
Disconnect the Transmission Solenoid Assembly harness connector.
NOTE: Check connectors - Clean/repair as necessary
Measure the resistance of the 5-volt Supply circuit between the Trans-
mission Solenoid Assembly harness connector and the ECM C2 har-
ness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 8
No>>
Repair 5-volt Supply circuit for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
8.CHECK THE 5 VOLT SUPPLY CIRCUIT FOR AN OPEN - INTERNAL
Reconnect the Transmission Solenoid Assembly harness connector.
Remove the Transmission Oil Pan perthe Service Information. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/FLUID -
STANDARD PROCEDURE)
Disconnect the Governor Pressure Sensor harness connector internal to
the transmission.
NOTE: Check connectors - Clean/repair as necessary
Measure the resistance of the 5-volt Supply circuit between the ECM
C2 harness connector and the Governor Pressure Sensor connector
internal to the transmission.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 9
No>>
Repair or replace the 5-volt Supply circuit for an open inter-
nal to the transmission.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
9.GOVERNOR PRESSURE SENSOR
Reconnect the ECM harness connectors.
NOTE: The ECM harness connectors must be connected during
this test.
Ignition on, engine not running.
Measure the voltage of the 5-volt Supply circuit at the Governor Pres-
sure Sensor connector internal to the transmission.
Is the voltage between 4.5 and 5.5 volts?
Ye s>>
Replace the Governor Pressure Sensor per the Service
Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE/GOVERNOR PRESSURE SENSOR -
REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Using the schematics as a guide, check the Engine Control Module (ECM) pins, terminals, and connec-
tors for corrosion, damage, or terminal push out. Pay particular attentiontoallpowerandgroundcir-
cuits. If no problems are found, replace and program the ECM per the ServiceInformation. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
10.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Use the Freeze Frame Data to help duplicate the conditions in which the DTC originally set. Pay particular attention
to the DTC set conditions, such as, VSS, MAP, ECT, and Load
Using the schematics as a guide, visually inspect the related wiring harness. Look for any chafed, pierced, pinched,
or partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken,bent, pushed out, or corroded terminals.
Wiggle the wiring and connectors while checking for any possible open or shorted circuits.
Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Theory of Operation
The Torque Converter Clutch (TCC) solenoid is used to engage the TCC which improves fuel economy.
When Monitored:
Continuously with the ignition on.
Set Condition:
This DTC will set if the voltage detected by the ECM for the Torque ConverterClutch SolenoidControl circuit
is different than the expected voltage. Note: To clear this DTC it is necessarytodrivethevehicleatasus-
tained speed which would allow the TCC and/or Overdrive Clutch to operate.
Possible Causes
TRANSMISSION CONTROL DTCS PRESENT
(T16) TRANSMISSION CONTROL OUTPUT CIRCUIT OPEN
(T16) TRANSMISSION CONTROL OUTPUT CIRCUIT SHORT TO GROUND
(T75) TCC SOLENOID CONTROL CIRCUIT SHORT TO GROUND
(T75) TCC SOLENOID CONTROL CIRCUIT SHORT TO OTHER CIRCUITS
TOTALLY INTEGRATED POWER MODULE (TIPM)
TORQUE CONVERTER CLUTCH SOLENOID
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 THERE ANY TRANSMISSION CONTROL OR TIPM DTCS PRESENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Are there any Transmission Control or TIPM DTCs also present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom(s). (Refer to 21 - TRANS-
MISSION/TRANSAXLE/AUTOMATIC - 48RE - DIAGNOSIS AND TESTING)
No>>
Go To 2
2.CHECK IF THE DTC IS CURRENT
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 3
No>>
Go To 12
3.CHECK THE (T16) TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT
Ignition on, engine not running.
With the scan tool, actuate the Transmission Control Output in the
ECM.
Using a 12-volt test light connected to ground, back probe the (T16)
Transmission Control Output circuit at the TIPM C10 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 cycle on and off and illuminate brightly?
Ye s>>
Go To 4
No>>
Go To 9
4.CHECK THE (T16) TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT
Ignition on, engine not running.
With the scan tool, actuate the Transmission Control Output in the
ECM.
Using a 12-volt test light connected to ground, back probe the (T16)
Transmission Control Output circuit at the Transmission Solenoid
Assembly 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 cycle on and off and illuminate brightly?
Ye s>>
Go To 5
No>>
Repair the (T16) Transmission Control Output Circuit for an
open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
5.CHECK THE (T75) TORQUE CONVERTER CLUTCH SOLENOID CIRCUIT
Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid Assembly harness connector.
Ignition on, engine not running.
With the scan tool, actuate the TCC Solenoid.
Using a 12-volt test light connected to 12-volts, check the (T75) TCC
Solenoid Control circuit in the Transmission Solenoid Assembly 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 cycle on and off and illuminate brightly?
Ye s>>
Check all internal wiring pertaining to the (T75) TCC Sole-
noid for an open, short, and bent or broken terminals. If no
internal wiring problems are found, replace the Transmis-
sion Solenoid Assembly per the Service Information. (Refer
8.(T75) TCC SOLENOID CONTROL CIRCUIT SHORT TO OTHER CIRCUITS
Measure the resistance between the (T75) TCC Solenoid Control circuit
and all other circuits in the Transmission Solenoid Assembly harness
connector.
Is the resistance below 5.0 ohms between the (T75) TCC Sole-
noid Control circuit and any other circuit in the Transmission
Solenoid Assembly harness connector?
Ye s>>
Repair the (T75) TCC Solenoid Control circuit for a short to
another circuit(s).
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Using the schematics as a guide, check the Engine Control
Module (ECM) pins, terminals, and connectors for corrosion,
damage, or terminal push out. Pay particular attention to all
power and ground circuits. If no problems are found,
replace and program the ECM per the Service Information.
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/ENGINE CONTROL MODULE - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
9.CHECK THE (T16) TRANSMISSION CONTROL OUTPUT CIRCUIT FOR OPEN.
Ignition on, engine not running.
Using the scan tool in the TIPM, actuate the Transmission.
Using a 12-volt test light connected to ground, back probe the (T16)
Transmission Control Output circuit at the TIPM C10 harness connector.
Does the test light illuminate brightly?
Ye s>>
Go To 10
No>>
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
problems are found, replace and program the TIPM per the
Service Information.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)