4.CHECK THE (K314) TTVA MOTOR (+) CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the ECM C1 and C2 harness connectors.
Measure the resistance of the (K314) TTVA Motor (+) circuit between
the ECM C1 harness connector and the TTVA harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the (K314) TTVA Motor (+) circuit for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
5.CHECK THE (K315) TTVA MOTOR (-) CIRCUIT FOR AN OPEN
Measure the resistance of the (K315) TTVA Motor (-) circuit between the
ECM C1 harness connector and the TTVA harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 6
No>>
Repair the (K315) TTVA Motor (-) circuit for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
8.CHECK THE (K315) TTVA MOTOR (-) CIRCUIT FOR A SHORT TO VOLTAGE
Measure the voltage of the (K315) TTVA Motor (-) circuit.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (K315) TTVA Motor (-) circuit for a short to volt-
age.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 9
9.CHECK THE (K314) TTVA MOTOR (+) CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
Turn the ignition off to the lock position.
Measure the resistance between the (K314) TTVA Motor (+) circuit and
every other circuit in the ECM C1 and C2 harness connectors.
Is the resistance below 5.0 ohms between the (K314) TTVA
Motor (+) circuit and any other circuit in the ECM C1 and C2
harness connectors?
Ye s>>
Repair the (K314) TTVA Motor (+) for a short to another cir-
cuit(s).
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 10
10.CHECK THE (K315) TTVA MOTOR (-) CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
Measure the resistance between the (K315) TTVA Motor (-) circuit and
every other circuit in the ECM C1 and C2 harness connectors.
Is the resistance below 5.0 ohms between the (K315) TTVA
Motor (-) circuit and any other circuit in the ECM C1 and C2
harness connectors?
Ye s>>
Repair the (K315) TTVA Motor (-) for a short to another cir-
cuit(s).
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 11
11 .CHECK THE ECM OPERATION
Turn the ignition off to the lock position.
Reconnect all previously disconnected connectors.
Turntheignitiononfortheperiodof30secondstoallowtheECMto
reset.
Turn the ignition off to the lock position.
Disconnect the TTVA harness connector.
Connect a 12-volt test light between the (K314) TTVA Motor (+) circuit
and the (K315) TTVA Motor (-) circuit in the TTVA harness connector.
Monitor the test light in the following step.
NOTE: The test light should momentarily flash brightly, one time,
immediately after the ignition is turned to the on position.
Ignition on, engine not running.
Did the test light illuminate brightly one time after turning the
ignition to the on position?
Ye s>>
Go To 12
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)
3.CHECK IF THE GOVERNOR PRESSURE IS BELOW 3 PSI
Turn the ignition off to the lock position.
Install a pressure gauge at the Governor Pressure test port. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 48RE - DIAGNOSIS AND TESTING)
NOTE: Use the appropriate pressure gauge for the pressure range measured.
CAUTION: Apply the parking brake.
Start the engine and allow the transmission to reach normal operating temperature above 43° C (110° F).
CAUTION: Apply the brakes.
With the engine at idle, place the gear selector in Drive.
Read the governor pressure on the pressure gauge.
Is the governor pressure on the pressure gauge below 21 kPa (3 psi) with the engine at idle and the
gear selector in Drive?
Ye s>>
The Governor Pressure Solenoid is functioning properly. Go To 7
No>>
Go To 10
4.GOVERNOR PRESSURE BETWEEN 40-55 WITH RELAY REMOVED
Place the gear selector in Park.
Turn the ignition off to the lock position.
Disconnect the TIPM C1 connector.
Start the engine and allow the transmission to reach normal operating temperature above 43° C (110° F).
WARNING: Do not wear loose clothing or jewelry when working on or near a running engine. Failure to
follow these instructions can result in personal injury or death.
NOTE: Disconnecting the TIPM connector may set various DTCs. Disregard anyDTCthatmaysetdueto
disconnecting the connector.
CAUTION: Apply the brakes.
Place the gear selector in Drive and allow the engine to idle for 30 seconds.
With the scan tool, read the Actual Governor Pressure at idle.
Is the governor pressure on the scan tool between 276 - 379 kPa (40 - 55 psi)?
Ye s>>
Go To 5
No>>
Go To 6
5.GOVERNOR PRESSURE SOLENOID
Turn the ignition off to the lock position.
Replace the Governor Pressure Solenoid per the Service Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE/GOVERNOR PRESSURE SENSOR - REMOVAL)
Start the engine and allow the transmission to reach normal operating temperature above 43° C (110° F).
With the scan tool, monitor the target governor pressure and actual governor pressure.
Drivethevehicleataconstantspeed40-48Km/h(25-30MPH).
NOTE: The Actual Governor Pressure should be within 21 kPa (3 psi) of the Target Governor Pressure
within 3 seconds.
Is the Actual Governor Pressure within 21 kPa (3 psi) of the Target GovernorPressure?
Ye s>>
Go To 13
No>>
Repair internal transmission leak. Inspect all components pertaining tothe Governor Pressure Sensor
and the Governor Pressure Solenoid. (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)
6.CHECK GAUGE PRESSURE 40-55 WITH RELAY OUT
Place the gear selector in Park.
Turn the ignition off to the lock position.
Disconnect the TIPM C1 connector.
Start the engine and allow the transmission to reach normal operating temperature above 43° C (110° F).
WARNING: Do not wear loose clothing or jewelry when working on or near a running engine. Failure to
follow these instructions can result in personal injury or death.
NOTE: Disconnecting the TIPM connector may set various DTCs. Disregard anyDTCthatmaysetdueto
disconnecting the connector.
CAUTION: Apply the brakes.
Place the gear selector in Drive with the engine at idle.
Read the governor pressure on the pressure gauge.
Is the governor pressure on the pressure gauge read between 276 - 379 kPa (40-55psi)?
Ye s>>
Go To 7
No>>
Go To 10
7.CHECK THE 5 VOLT SUPPLY CIRCUIT FOR AN OPEN - EXTERNAL
Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid Assembly harness connector.
Disconnect the ECM harness connectors.
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 the 5-volt Supply circuit for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
10.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 transmission fluid and/or excessive debris.
Is the transmission fluid burnt and/or contain excessive debris?
Ye s>>
Repair the internal transmission per the Service Information. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 48RE - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 11
11 .CHECK THE VALVE BODY
Replace the Governor Pressure Solenoid per the Service Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE/GOVERNOR PRESSURE SENSOR - REMOVAL)
Install a pressure gauge at the governor pressure test port. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 48RE - DIAGNOSIS AND TESTING)
Start the engine.
Warm the transmission to normal operating temperature.
CAUTION: Apply the brakes.
Place the gear selector in Drive and allow the engine to idle.
Read the governor pressure on the pressure gauge in Drive.
Is the governor pressure on the gauge below 21 kPa (3 psi)?
Ye s>>
Go To 12
No>>
Repair or replace the Valve Body per the Service Information. (Refer to 21 -TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
12.VERIFY OPERATION - TEST DRIVE
Remove the pressure gauge from the transmission. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC -
48RE - DIAGNOSIS AND TESTING)
Test drive the vehicle.
Be sure to drive the vehicle at a constant speed of 40-48 Km/h or 25-30 MPH 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>>
Te s t C o m p l e t e .
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
Theory of Operation
The Governor Pressure Control System is used to regulate the governor pressure which controls the shifts for first,
second, and third gear. The Governor Pressure Control System test verifies that the requested pressure and the
actual pressure are within a predetermined tolerance.
When Monitored:
While the engine is running and the gear selector is in the Drive position.
Set Condition:
This DTC will set if the monitored Governor Pressure is greater than 41.4 kPa(6psi)for5secondswhilethe
gear selector is in the Drive position with the road speed equal to zero - sixtimes during a drive cycle. The
transmission oil temperature must be between 23 - 88° C (73 - 190° F).
Possible Causes
OTHER TRANSMISSION DTC’S PRESENT
5 VOLT SUPPLY CIRCUIT OPEN
5 VOLT SUPPLY CIRCUIT OPEN INSIDE THE TRANSMISSION
TRANSMISSION OIL BURNT OR OIL PAN HAS EXCESSIVE DEBRIS - INTERNAL TRANSMISSION DAMAGE
GOVERNOR PRESSURE SENSOR
GOVERNOR PRESSURE SOLENOID
VA LV E B O D Y
ENGINE CONTROL MODULE 5 VOLT SUPPLY
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.OTHER TRANSMISSION DTC’S PRESENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Are there 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 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 11
3.CHECKING FOR GOVERNOR PRESSURE ABOVE 6 PSI
Start the engine.
CAUTION: Apply the parking brake.
Warm the transmission to a normal operating temperature above 43° C (110° F).
CAUTION: Firmly apply the brakes.
With the engine RPM at idle, place the gear selector in Drive.
With the scan tool, read the governor pressure.
Is the governor pressure above 41.4 kPa (6 psi)?
Ye s>>
Go To 4
No>>
Go To 11
4.GOVERNOR PRESSURE MATCH GAUGE PRESSURE
Turn the ignition off to the lock position.
Install 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.
Warm the transmission to a normal operating temperature above 43° C (110° F).
CAUTION: Firmly apply the brakes.
With the engine RPM at idle, place the gear selector in Drive.
With the scan tool, read the governor pressure and compare the scan tool reading to the pressure gauge reading.
Does the scan tool Governor Pressure reading match the pressure gauge reading within 6.9 kPa (1
psi)?
Ye s>>
Go To 5
No>>
Go To 8
5.CHECK FOR BURNT TRANSMISSION FLUID AND/OR EXCESSIVE DEBRIS IN THE TRANSMISSION OIL
PA N
Turn the ignition off to the lock position.
Remove the transmission oil pan per the Service Information and inspect for burnt transmission fluid and excessive
debris. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/FLUID - STANDARD PROCEDURE)
Is the transmission fluid burnt or does the transmission oil pan contain 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 6
6.REPLACE THE GOVERNOR PRESSURE SOLENOID AND CHECK THE VALVE BODY
Replace the Governor Pressure Solenoid per with the Service Information.(Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 48RE/GOVERNOR PRESSURE SENSOR - REMOVAL)
Start the engine.
Warm the transmission to a normal operating temperature above 43° C (110° F).
CAUTION: Firmly apply the brakes.
With the engine RPM at idle, place the gear selector in Drive.
Read the governor pressure on the pressure gauge.
Is the governor pressure on the pressure gauge above 41.4 kPa (6 psi) with the engine RPM at idle and