Page 3545 of 5267
P0748-PRESSURE SOL CONTROL/TRANS RELAY CIRCUITS (GAS)
For a complete wiring diagramRefer to Section 8W
Page 3549 of 5267

7.CHECK THE (T118) GOVERNOR PRESSURE SOLENOID CONTROL CIRCUIT FOR A SHORT TO
ANOTHER CIRCUIT
Turn the ignition off to the lock position.
Remove the Transmission Control Relay.
Measure the resistance between the (T118) Governor Pressure Sole-
noid Control circuit and all other circuits in the Transmission Solenoid
Assembly harness connector.
Is the resistance below 5.0 ohms between the (T118) Governor
Pressure Solenoid Control circuit and any other circuit in the
Transmission Solenoid Assembly harness connector?
Ye s>>
Repair the (T118) Governor Pressure Solenoid Control cir-
cuit for a short to another circuit(s).
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 8
8.CHECK THE GOVERNOR PRESSURE SOLENOID
Remove the Transmission Oil Pan per the Service Information. (Refer to 21 -TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE/FLUID - STANDARD PROCEDURE)
Check all internal wiring pertaining to the Governor Pressure Solenoid for an open, short, and bent or broken ter-
minals.
If no internal wiring problems are found, replace the Governor Pressure Solenoid per the Service Information. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/GOVERNOR PRESSURE SENSOR - REMOVAL)
Drive the vehicle performing multiple upshifts and downshifts.
With the scan tool, read Transmission DTCs.
Does the DTC reset?
Ye s>>
Using the schematics as a guide, check the Powertrain Control Module (PCM)pins, terminals, and con-
nectors 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 PCM per the Service Information. (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/POWERTRAIN CONTROL MODULE -
REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (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 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
Page 3551 of 5267

11 .CHECK THE (T515) TRANSMISSION CONTROL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C2 harness connector.
Connect a jumper wire between cavity 30in the PCM 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 (PCM) 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 PCM per the Service Information.
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/ENGINE CONTROL MODULE - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Repair the (T515) Transmission Control circuit for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
12.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 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Page 3552 of 5267
P0751-O/D SWITCH PRESSED (LO) MORE THAN 5 MINUTES
For a complete wiring diagramRefer to Section 8W
Page 3555 of 5267
P0753-TRANS 3-4 SHIFT SOL/TRANS RELAY CIRCUITS (GAS)
For a complete wiring diagramRefer to Section 8W
Page 3557 of 5267

2.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 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
PCM.
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 10
4.CHECK THE 3-4 SHIFT SOLENOID
With the scan tool, actuate the Overdrive (3-4) Solenoid.
Using a 12-volt test light connected to 12-volts, check the (T9) 3-4 Shift
Solenoid Control circuit in the Transmission Solenoid Assembly harness
connector.
Does the test light cycle on and off and illuminate brightly?
Ye s>>
Check all internal wiring pertaining to the 3-4 Shift Solenoid
for an open, short, and bent or broken terminals. If no inter-
nal wiring problems are found, replace the Transmission
Solenoid Assembly per the Service Information. (Refer to 21
- TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/
VA LV E B O D Y - R E M O VA L )
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 5
Page 3561 of 5267

11 .CHECK THE (T515) TRANSMISSION CONTROL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C2 harness connector.
Connect a jumper wire between cavity 30in the PCM 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 (PCM) 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 PCM per the Service Information.
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/ENGINE CONTROL MODULE - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Repair the (T515) Transmission Control circuit for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
12.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 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Page 3562 of 5267
P0783-3-4 SHIFT SOL, NO RPM DROP AT LOCKUP (GAS)
For a complete wiring diagramRefer to Section 8W