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)
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
3.CHECK THE (T38) GOVERNOR PRESSURESENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid Assembly harness connector.
Disconnect the ECM C1 and C2 harness connectors.
Measure the resistance between Ground and the (T38) Governor Pres-
sure Sensor Signal circuit in the Transmission Solenoid Assembly har-
ness connector.
Is the resistance greater than 100k ohms?
Ye s>>
Go To 4
No>>
Repair the (T38) Governor Pressure Sensor Signal circuit
for a short to ground.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (DIESEL). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)
4.CHECK THE (T38) GOVERNOR PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO ANOTHER
CIRCUIT
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 5
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
3.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 ECM, actuate the Transmission.
Using a 12-volt test light connected to ground, 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
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)
No>>
Go To 4
4.CHECK THE (T515) TRANSMISSION CONTROL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the ECM C2 harness connector.
Connect a jumper wire between cavity 5 in the ECM C2 harness con-
nector and ground.
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 illuminate brightly?
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>>
Repair the (T515) Transmission Control 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 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 circuit is different than the
expected voltage for the period 3.0 seconds.
Possible Causes
(T515) TRANSMISSION CONTROL CIRCUIT SHORT TO VOLTAGE
(T515) TRANSMISSION CONTROL CIRCUIT SHORT TO ANOTHER CIRCUIT
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 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