Page 3329 of 5267

AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Using the schematics as a guide, check the Powertrain Control Module (PCM)terminals for corrosion,
damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems
are found, replace the PCM per the Service Information. With the scan tool,perform QUICK LEARN.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
6.CHECK WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wires while checking for shorted and open circuits.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Where there any problems found?
Ye s>>
Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Page 3330 of 5267
P1776-SOLENOID SWITCH VALVE LATCHED IN LR POSITION
For a complete wiring diagramRefer to Section 8W.
Page 3331 of 5267

When Monitored:
Continuously when performing partial or full EMCC - PEMCC or FEMCC.
Set Condition:
If the transmission senses the L/R pressure switch closing while performing PEMCC or FEMCC. This DTC will
set after two unsuccessful attempts toperform PEMCC or FEMCC. This DTC cantake up to five minutes of
problem identification before illuminating the MIL.
Possible Causes
RELATED DTC P0841 PRESENT
LR PRESSURE SWITCH SENSE CIRCUIT OPEN
LR PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
SOLENOID SWITCH VALVE
POWERTRAIN CONTROL MODULE
INTERMITTENT WIRING AND CONNECTORS
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
Theory of Operation
The Solenoid Switch Valve (SSV) controls the direction of the transmission fluid when the L/R Solenoid is energized.
The SSV will be in the downshifted position in 1st gear, thus directing the fluid to the L/R clutch circuit. In 2nd
through 5th gears, it will be in the upshifted position and directing the fluid into the torque converter clutch (TCC).
When in 2nd, 2nd Prime, 3rd, 4th, or 5th gear, the Torque Converter Clutch (TCC) can be engaged when certain
conditions are met. The TCC piston is electronically modulated by increasing the duty cycle of the L/R solenoid until
the torque converter slip difference (difference between engine and transmission input speed) is within 60 RPM.
Then the L/R solenoid isfully energized (FEMCC - 100% duty cycle). Torque converter slip is monitored in FEMCC
to ensure adequate clutch capacity.
Diagnostic Test
1.CHECKFORRELATEDDTCS
With the scan tool, check for other transmission DTCs.
Is the DTC P0841 present also?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
2.CHECK TO SEE IF DTC P1776 IS CURRENT
With the scan tool, Check the STARTS SINCE SET counter.
NOTE: NOTE: This counter only applies to the last DTC set.
Is the STARTS SINCE SET counter 2 or less?
Ye s>>
Go To 3
No>>
Go To 7
Page 3332 of 5267

3.CHECK THE PCM AND WIRING
Turn the ignition off to the lock position.
Remove the Ignition Switch Feed fuse from the TIPM.
CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being
startedingear.
WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in
personal injury or death.
Install the Transmission Simulator, Miller tool #8333.
Ignition on, engine not running.
With the Transmission Simulator, turn the Pressure Switch selector switchtotheLRposition.
With the scan tool, monitor the LR Pressure Switch state while pressing thePressure Switch Test button on the
Transmission Simulator.
Did the state of the LR Pressure Switch change while pressing the Pressure Switch Test button?
Ye s>>
Go To 4
No>>
Go To 5
4.CHECK THE SOLENOID SWITCH VALVE
Remove the Valve Body per the Service Information.
Inspect the Solenoid Switch Valve and plugs for sticking in the bore and/orwear.
Were there any problems found?
Ye s>>
Clean and repair as necessary per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 7
5.CHECK THE LR PRESSURE SWITCH SENSE CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the Transmission Simulator, Miller tool #8333.
Disconnect the PCM C4 harness connector and connect Miller tool
#8815.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller tool #8815 to per-
form diagnosis.
Measure the resistance of the (T50) LR Pressure Switch Sense circuit
between the Solenoid/TRS Assembly harness connector and the appro-
priate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T50) LR Pressure Switch Sense circuit for an
open.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Go To 6
Page 3333 of 5267

6.CHECK THE (T50) LR PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (T50) LR Pressure
Switch Sense circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (T50) LR Pressure Switch Sense circuit for a
short to ground.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Using the schematics as a guide, check the Powertrain
Control Module (PCM) terminals for corrosion, damage, or
terminal push out. Pay particular attention to all power and
ground circuits. If no problems are found, replace the PCM
per the Service Information.With the scan tool, perform
QUICK LEARN.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
7.CHECK WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wires while checking for shorted and open circuits.
This DTC can also be set by the Solenoid Switch Valve intermittently sticking in it’s bore under extreme temperature
conditions, or by a worn Solenoid Switch Valve or plugs.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Where there any problems found?
Ye s>>
Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Page 3334 of 5267

P1790-FAULT IMMEDIATELY AFTER SHIFT
For a complete wiring diagramRefer to Section 8W
When Monitored:
After a speed ratio error is stored.
Set Condition:
This DTC is set if the associated speed ratio DTC is stored within 1.3 seconds after a shift.
Possible Causes
FAULT AFTER SHIFT
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
Theory of Operation
This DTC will only be stored along with a gear ratio DTC. If this DTC is set, itindicates a probable hydraulic (line
pressure) or mechanical problem exists. Diagnosing the transmission should be based on the associated speed
ratio DTC and mechanical causes should be considered first.
INTENDED GEAR CLUTCHES APPLYING RECOMENDED DTC
REVERSE UD** - MS P0738
1ST UD - LR* P0731
2ND UD - 2C P0732
2ND PRIME UD - 4C P1736
3RD UD - OD/MS P0733
4TH OD/MS - 2C P0734
5TH OD/MS - 2C P0735
* L/R is used only up to 150 output RPM in 1st gear. ** UD will show as applied inReversebuttheUDclutchis
actually released. OD/MS is OD and/or MS.
Diagnostic Test
1.INTENDED GEAR TO APPLIED CLUTCH
With the scan tool, check the DTC EVENT DATA to determine in which gear the slippage occurred and the clutches
that were applied.
WiththeDTCEVENTDATA,usetheinformationprovidedabovetodeterminethe proper symptom for diagnosis.
View repair
Repair
Refer to the Transmission category and perform the appropriate symptom identified from the DTC
EVENT DATA, intended gear, and applied clutches.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
Page 3335 of 5267
P1794-SPEED SENSOR GROUND ERROR
For a complete wiring diagramRefer to Section 8W
Page 3336 of 5267

When Monitored:
The gear ratio is monitored continuously while the Transmission is in gear.
Set Condition:
After a controller reset in neutral and a ratio of input to output, of 1 to 2. ThisDTCcantakeuptofiveminutes
of problem identification before illuminating the MIL.
Possible Causes
(T13) SPEED SENSOR GROUND CIRCUIT OPEN
(T13) SPEED SENSOR GROUND CIRCUIT SHORT TO GROUND
(T13) SPEED SENSOR GROUND CIRCUIT SHORT TO VOLTAGE
POWERTRAIN CONTROL MODULE
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
Theory of Operation
The transmission system uses two speed sensors, one to measure input RPM and one to measure output RPM.
These inputs are essential for proper transmission operation. Therefore, the integrity of this data is verified through
the following checks:
1) When in gear, if the gear ratio does not compare to a known gear ratio, the corresponding in-gear trouble code
is set (DTCs P0731–36).
2) An excessive change in input or output speeds indicating signal intermittent which may result in the DTCs P0715
and/or P0720 to set.
3) If the common speed sensor ground circuit is lost, both sensor inputs will read the signal from the input speed
sensor at idle in neutral. Since the input speed sensor reads 60 teeth from the input clutch hub and the output
speed sensor reads 30 teeth from the park gear, the result is an apparent speed ratio of 1:2 and may cause the
DTC P1794 to set when at a stop.
Diagnostic Test
1.CHECK TO SEE IF DTC P1794 IS CURRENT
Engine Running, Shift lever in park.
With the scan tool, read the Transmission Output and Input Speed Sensor states.
Is the Output Speed Sensor reading twice the Input Speed Sensor reading?
Ye s>>
Go To 2
No>>
Go To 6
2.PCM AND WIRING
Turn the ignition off to the lock position.
Remove the Ignition Switch Feed fuse from the TIPM.
CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being
startedingear.
WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in
personal injury or death.
Install the Transmission Simulator, Miller tool 8333.
With the Transmission Simulator, set the Input/Output Speed selector switch to the
3000/1000position. Turn the
Input/Output Speed switch to
ON.
Ignition on, engine not running.