When Monitored:
Continuously with the ignition on and engine running.
Set Condition:
The Transmission governor pressure set point is above a threshold while inparkortheP/Nswitchisindrive
during an engine start.
Possible Causes
TRS CONNECTOR DAMAGE OR CORROSION
ECM CONNECTOR DAMAGE OR CORROSION
(T41) P/N POSITION SWITCH SENSE CIRCUIT OPEN
(T41) P/N POSITION SWITCH SENSE CIRCUIT SHORT TO GROUND
(T41) P/N POSITION SWITCH SENSE CIRCUIT SHORT TO ANOTHER CIRCUIT
TRANSMISSION RANGE 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 SCAN TOOL DISPLAYS P/N AND D/R IN THE CORRECT POSITION
Ignition on, engine not running.
With the scan tool, monitor the PNP switch input state.
Move the gear selector through all gear positions Park to 1st and back to Park.
Did the scan tool display P/N and D/R in the correct gear positions?
Ye s>>
Go To 8
No>>
Go To 2
2.CHECK THE TRS CONNECTOR FOR DAMAGE OR CORROSION
Turn the ignition off to the lock position.
Disconnect the Transmission Range Sensor harness connector.
Inspect the Transmission Range Sensor harness wiring and connector for damage, pushed out pins, or corrosion,
etc.
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>>
Go To 3
3.CHECK THE ECM CONNECTOR FOR DAMAGE OR CORROSION
Disconnect the ECM C2 harness connector.
Inspect the ECM wiring and connector for damage, pushed out pins, or corrosion, etc.
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>>
Go To 4
6.CHECK THE (T41) P/N POSITION SWITCH SENSE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
Measure the resistance between the (T41) P/N Position Switch Sense
circuit and all other circuits in the ECM C1 and C2 harness connectors.
Is the resistance greater 100k ohms between the (T41) P/N
Position Switch Sense circuitand any other circuit(s) in the
ECM C1 and C2 harness connectors?
Ye s>>
Go To 7
No>>
Repair the (T41) P/N Position Switch Sense 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)
7.CHECK THE TRANSMISSION RANGE SENSOR
Reconnect the Transmission Range Sensor harness connector.
Move the gear selector through all gear positions, from Park to 1st and
back.
While moving the gear selector through the gear positions, measure the
resistance between ground and the (T41) P/N Position Switch Sense
circuit in the ECM harness connector.
NOTE: The circuit is grounded in Park and Neutral and open in the
other positions.
Did the display change from above 100k ohms (open) to below
5.0 ohms (grounded)?
Ye s>>
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)
No>>
Replace the Transmission Range Sensor per Service Infor-
mation. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE/TRANSMISSION RANGE SENSOR -
REMOVAL)
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 when the monitored sense voltage from the Governor Pressure Sensor is above 4.89 volts
for the period of 8.5 seconds.
Possible Causes
OTHER TRANSMISSION DTC’S PRESENT
PARK NEUTRAL DTC PRESENT
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND CIRCUIT OPEN
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO ANOTHER CIRCUIT
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT OPEN INSIDE TRANSMISSION
(K900) SENSOR GROUND CIRCUIT OPEN INSIDE TRANSMISSION
(T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE INSIDE TRANSMISSION
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 11
5.CHECK THE (T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
Ignition on, engine not running.
Measure the voltage of the (T38) Governor Pressure Sensor Signal cir-
cuit in the Transmission Solenoid Assembly harness connector.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (T38) Governor Pressure Sensor Signal circuit
for a short to voltage.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 6
6.CHECK THE (T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO ANOTHER
CIRCUIT
Turn the ignition off to the lock position.
Measure the resistance between the (T38) Governor Pressure Sensor
Signal circuit and all other circuits in the Transmission Solenoid Assem-
bly harness connector.
Is the resistance below 100k ohms between the (T38) Governor
Pressure Sensor Signal circuit and any other circuit(s) in the
Transmission Solenoid Assembly harness connector?
Ye s>>
Repair the (T38) Governor Pressure Sensor Signal 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>>
Go To 7
9.CHECK THE (T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
INTERAL
NOTE: The Transmission Solenoid Assembly harness connector
must be connected before proceeding.
Ignition on, engine not running.
Measure the voltage of the (T38) Governor Pressure Sensor Signal cir-
cuit in the Governor Pressure Sensor harness connector (inside trans-
mission).
Is the voltage above 0.5 volt?
Ye s>>
Replace the Transmission Solenoid Assembly per the Ser-
vice 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)
No>>
Go To 10
10.ENGINE CONTROL MODULE
Turn the ignition off to the lock position.
Reconnect the ECM harness connector.
Reconnect the Transmission Solenoid Assembly harness connector.
Ignition on, engine not running.
With the scan tool, erase DTCs.
Connect a jumper wire between the (T38) Governor Pressure Sensor
Signal circuit and the (K900) Sensor Ground circuit in the Transmission
Governor Pressure Sensor harness connector.
With the scan tool, read DTCs.
Did the DTC P0869 set?
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)
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
5.CHECK THE TRANSMISSION SOLENOID ASSEMBLY
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/Transmission Temperature Sensor
connector (inside transmission).
Measure the resistance between the (T38) Governor Pressure Sensor
Signal circuit and all other circuits in the ECM C1 and C2 harness con-
nectors.
Is the resistance below 100k ohms between the (T38) Governor
Pressure Sensor Signal circuit any other circuits in the ECM
C2 harness connector?
Ye s>>
Replace the Transmission Solenoid Assembly per the Ser-
vice Information.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 6
6.CHECK THE GOVERNOR PRESSURE SENSOR SENSOR
Turn the ignition on.
With the scan tool, erase DTCs.
Connect a jumper wire between the (T38) Governor Pressure Sensor
Signal circuit and the (F856) 5-volt Supply circuit in the Governor Pres-
sure Sensor connector.
With the scan tool, read DTCs.
Did the DTC P0868 set?
Ye s>>
Inspect the Governor Pressure Sensor wiring for damage. If
no problems are found, replace the Governor Pressure Sen-
sor per the Service Information.
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)
Theory of Operation
The Transmission Control Output from the Totally Integrated Power Module(TIPM) supplies power to the TCC,
Overdrive, and Governor Pressure Solenoids when in normal operating mode. The Transmission Control circuit is
constantly monitored by the ECM. If the expected state of the TransmissionControl circuit is different then the
expected state, a corresponding DTC will set and the ECM will de-energize the Transmission Control and place the
transmission in Limp-in.
When Monitored:
Continuously with the Ignition on.
Set Condition:
This DTC will set if the ECM monitored voltage of the Transmission Control Relay 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 GROUND
(T515) TRANSMISSION CONTROL CIRCUIT SHORT TO ANOTHER CIRCUIT
TOTALLY INTEGRATED POWER MODULE (TIPM)
ENGINE 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 5
2.CHECK THE TIPM FOR CODES
Ignition on, engine not running.
With the scan tool, read TIPM DTCs.
Are there any TIPM DTCs?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom(s).
No>>
Go To 3