Page 3694 of 5267

3.CHECK THE 3-4 SOLENOID
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 3-4 (Overdrive) Solenoid.
Using a 12-volt test light connected to 12-volts, check the 3-4 Solenoid
Control circuit in the TransmissionSolenoid Assembly harness connec-
tor.
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 3-4 Solenoid for
an open, short and bent or broken terminals. If no internal
wiring problems are found, replace the Transmission Sole-
noid Assembly per the Service Information. (Refer to 21 -
TRANSMISSION/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 4
4.CHECK TO (T9) 3-4 SOLENOID CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
Turn the ignition off to the lock position.
Disconnect the ECM harness connectors.
Ignition on, engine not running.
Measure the voltage of the (T9) 3-4 Solenoid Control circuit.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (T9) 3-4 Solenoid Control 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 5
Page 3696 of 5267
7.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary set this DTC are not present at this time.
Use the Freeze Frame Data to help duplicate the conditions that set the DTC.Pay particular attention to the DTC
set conditions, such as, VSS, MAP, ECT, and Load.
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.
Refer to any 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 .
Page 3697 of 5267
P128B-TCM POWER CONTROL CIRCUIT 2 LOW - TIPM
For a complete wiring diagramRefer to Section 8W.
Page 3699 of 5267

3.CHECK THE (T16) TRANSMISSION CONTROL OUTPUT CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Connect the TIPM C10 harness connector.
Disconnect the Transmission Solenoid harness connector.
Ignition on, engine not running.
Using the scan tool under the TIPM Actuators, actuate the Transmission
control output.
Using a 12-volt test light connected to ground, check the (T16) Trans-
mission Control Output circuit at the Transmission Solenoid 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 illuminate brightly?
Ye s>>
Go To 4
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)
4.TOTALLY INTEGRATED POWER MODULE
NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors.
Pay particular attention to allPower and voltage circuits.
Were 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>>
Replace the Totally Integrated Power Module per Service Information.
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
5.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Were 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 .
Page 3700 of 5267
P128C-TCM POWER CONTROL CIRCUIT 2 HIGH - TIPM
For a complete wiring diagramRefer to Section 8W.
Page 3702 of 5267

3.TOTALLY INTEGRATED POWER MODULE
NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors.
Pay particular attention to allPower and voltage circuits.
Were 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>>
Replace the Totally Integrated Power Module per Service Information.
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
4.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Were 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 .
Page 3703 of 5267
P128D-TCM POWER CONTROL CIRCUIT 2 OPEN - TIPM
For a complete wiring diagramRefer to Section 8W.
Page 3705 of 5267
4.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Were 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 .