P0734-GEAR RATIO ERROR IN 4TH
For a complete wiring diagramRefer to Section 8W
When Monitored:
Continuously with the ignition on, engine running, with the transmissionin gear.
Set Condition:
If the ratio of the Input RPM to the Output RPM does not match the current gearratio. This DTC can take up
to five minutes of problem identification before illuminating the MIL.
Possible Causes
LOW FLUID LEVEL
INPUT SPEED SENSOR OR WIRING
VALVE BODY ACCUMULATOR COVER FAILED
CUT OD OR 4C ACCUMULATOR SEAL
CRACKED OD OR 4C ACCUMULATOR PISTON
BROKEN OR MISSING OD BLEED ORIFICE IN MAIN VALVE BODY
CUT 4C TOWER SEAL
TRANSMISSION SOLENOID/TRS ASSEMBLY
CUT OR MISSING #5 OR #6 CHECK BALL
WORN SOLENOID SWITCH VALVE OR PLUGS
CUT OD OR 4C PISTON SEAL
STUCK MAIN REGULATOR VALVE
BURNED OD OR 4C CLUTCH
BROKEN OR MISSING 4C BLEED ORIFICE IN 2C/4C RETAINER
BROKEN REACTION SHAFT SUPPORT SEAL RING
POOR MACHINING ON PUMP VALVE BODY FACE
LOOSE / MISSING DRIBBLER ORIFICE ASSEMBLY IN REACTION SHAFT SUPPORT
CRACKED / LOOSE / MISSING OD/REVERSE PISTON BLEED ORIFICE
BROKEN REVERSE CARRIER HUB WELD
BROKEN REVERSE SUN GEAR WELD TO REACTION CARRIER
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) Once in a particular gear, if the gear ratio varies from the correct 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 may result in the DTCs P0715 and/or
P0720 being set.
3) If the common speed sensor ground circuit is lost, both sensor inputs will read the pulses from the input speed
sensor when at a stop in neutral. Since the input speed sensor reads 60 teethfrom 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.
P0735-GEAR RATIO ERROR IN 5TH
For a complete wiring diagramRefer to Section 8W
When Monitored:
Continuously with the ignition on, engine running, with the transmissionin gear.
Set Condition:
If the ratio of the Input RPM to the Output RPM does not match the current gearratio. This DTC can take up
to five minutes of problem identification before illuminating the MIL.
Possible Causes
LOW FLUID LEVEL
INPUT SPEED SENSOR OR WIRING
VALVE BODY ACCUMULATOR COVER FAILED
CUT OD OR 2C ACCUMULATOR SEAL
CRACKED OD OR 2C ACCUMULATOR PISTON
BROKEN OR MISSING OD BLEED ORIFICE IN MAIN VALVE BODY
CUT 2C TOWER SEAL
TRANSMISSION SOLENOID/TRS ASSEMBLY
CUT OR MISSING #5, #6, OR #7 CHECK BALL
WORN SOLENOID SWITCH VALVE OR PLUGS
CUT OD OR 2C PISTON SEAL
STUCK MAIN REGULATOR VALVE
BURNED OD OR 2C CLUTCH
BROKEN OR MISSING 2C BLEED ORIFICE IN 2C/4C RETAINER
BROKEN REACTION SHAFT SUPPORT SEAL RING
POOR MACHINING ON PUMP VALVE BODY FACE
LOOSE / MISSING DRIBBLER ORIFICE ASSEMBLY IN REACTION SHAFT SUPPORT
CRACKED / LOOSE / MISSING OD/REVERSE PISTON BLEED ORIFICE
BROKEN REVERSE CARRIER HUB WELD
BROKEN REVERSE SUN GEAR WELD TO REACTION CARRIER
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) Once in a particular gear, if the gear ratio varies from the correct 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 may result in the DTCs P0715 and/or
P0720 being set.
3) If the common speed sensor ground circuit is lost, both sensor inputs will read the pulses from the input speed
sensor when at a stop in neutral. Since the input speed sensor reads 60 teethfrom 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.
P0736-GEAR RATIO ERROR IN REVERSE
For a complete wiring diagramRefer to Section 8W
When Monitored:
Continuously with the ignition on, engine running, with the transmissionin gear.
Set Condition:
If the ratio of the Input RPM to the Output RPM does not match the current gearratio. This DTC can take up
to five minutes of problem identification before illuminating the MIL
Possible Causes
LOW FLUID LEVEL
CUT LR TOWER SEAL ON MAIN VALVE BODY
CUT LR CLUTCH PISTON SEALS
BROKEN OR MISSING LR CLUTCH BLEED ORIFICE (IN LR CLUTCH RETAINER)
CUT LR ACCUMULATOR PISTON SEAL IN MAIN VALVE BODY
CRACKED LR ACCUMULATOR PISTON IN MAIN VALVE BODY
CUT OD/REV PISTON SEALS
BROKEN OR MISSING OD/REV BLEED ORIFICE (IN OD/REV CLUTCH PISTON)
BROKEN REVERSE CARRIER HUB WELD
BROKEN REVERSE SUN GEAR WELD TO THE REACTION CARRIER
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) Once in a particular gear, if the gear ratio varies from the correct 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 may result in the DTCs P0715 and/or
P0720 being set.
3) If the common speed sensor ground circuit is lost, both sensor inputs will read the pulses from the input speed
sensor when at a stop in neutral. Since the input speed sensor reads 60 teethfrom 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.
Diagnostic Test
1.CHECKFORRELATEDDTCS
With the scan tool, check for other transmission DTC’s
Are there any Transmission; solenoid, line pressure, speed sensor, and/or loss of prime DTC’s present?
Ye s>>
Refer to appropriate symptom in the Transmission category. Perform the test for P0944-LOSS OF
PRIME first if it is present.
No>>
Go To 2
When Monitored:
Initially at power-up, then every 10 seconds thereafter. The solenoid circuits will also be tested immediately
after a gear ratio or pressure switch error is detected.
Set Condition:
After three consecutive solenoid continuity test failures, or one failure if test is run in response to a gear ratio
or pressure switch error.Note: This DTC is strictly an electrical fault and does not apply to any internal
transmission failures.
Possible Causes
RELATED TIPM TCM DTCS PRESENT
(T20) LR SOLENOID CONTROL CIRCUIT SHORT TO OTHER CIRCUITS
(T20) LR SOLENOID CONTROL CIRCUIT OPEN
(T20) LR SOLENOID CONTROL CIRCUIT SHORT TO GROUND
TRANSMISSION SOLENOID/TRS ASSEMBLY
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 Control System uses six electronically controlled solenoids that allow hydraulic fluid to be applied
to various friction elements (clutches), which enables the gear requested. The continuity of each solenoid circuit is
periodically tested. Each inactive solenoid is turned on for a few milliseconds, then off. Each active solenoid is
turned off for a few milliseconds, then on. This pulsing of voltage to the solenoid causes an inductive spike which
can be sensed by the Transmission Control System. If an inductive spike is not sensed by the Transmission Control
System during the continuity check, it is tested again. If the test fails three consecutive times, the appropriate Diag-
nostic Trouble Code (DTC) is set. If the solenoid test is run in response to agear ratio or pressure switch error, one
failure will result in setting the appropriate DTC.Note: This DTC is strictly an electrical fault and does not apply
to any internal transmission failures.
Diagnostic Test
1.CHECK FOR TIPM TCM DTCS
With the scan tool, check for other transmission DTCs.
Are there any TIPM TCM DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
2.CHECK TO SEE IF P0750 IS PRESENT
Ignition on, engine not running.
With the scan tool, erase all Transmission DTC’s.
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 scan tool, actuate the LR Solenoid.
When Monitored:
Initially at power-up, then every 10 seconds thereafter. The solenoid circuits will also be tested immediately
after a gear ratio or pressure switch error is detected.
Set Condition:
After three consecutive solenoid continuity test failures, or one failure if test is run in response to a gear ratio
or pressure switch error.Note: This DTC is strictly an electrical fault and does not apply to any internal
transmission failures.
Possible Causes
RELATED TIPM TCM DTCS PRESENT
(T219) 2C SOLENOID CONTROL CIRCUIT SHORT TO OTHER CIRCUITS
(T219) 2C SOLENOID CONTROL CIRCUIT OPEN
(T219) 2C SOLENOID CONTROL CIRCUIT SHORT TO GROUND
TRANSMISSION SOLENOID/TRS ASSEMBLY
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 Control System uses six electronically controlled solenoids that allow hydraulic fluid to be applied
to various friction elements (clutches), which enables the gear requested. The continuity of each solenoid circuit is
periodically tested. Each inactive solenoid is turned on for a few milliseconds, then off. Each active solenoid is
turned off for a few milliseconds, then on. This pulsing of voltage to the solenoid causes an inductive spike which
can be sensed by the Transmission Control System. If an inductive spike is not sensed by the Transmission Control
System during the continuity check, it is tested again. If the test fails three consecutive times, the appropriate Diag-
nostic Trouble Code (DTC) is set. If the solenoid test is run in response to agear ratio or pressure switch error, one
failure will result in setting the appropriate DTC.Note: This DTC is strictly an electrical fault and does not apply
to any internal transmission failures.
Diagnostic Test
1.CHECK FOR TCM TIPM DTCS
With the scan tool under TIPM, check for TCM Power Input DTCs.
Are there any TIPM TCM Power Input DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
2.CHECK TO SEE IF P0755 IS PRESENT
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 scan tool, actuate the 2C Solenoid.
Did the 2C Solenoid LED blink on and off on the Transmission Simulator?
Ye s>>
Go To 3
No>>
Go To 4
When Monitored:
Initially at power-up, then every 10 seconds thereafter. The solenoid circuits will also be tested immediately
after a gear ratio or pressure switch error is detected.
Set Condition:
After three consecutive solenoid continuity test failures, or one failure if test is run in response to a gear ratio
or pressure switch error.Note: This DTC is strictly an electrical fault and does not apply to any internal
transmission failures.
Possible Causes
RELATED TIPM TCM DTCS PRESENT
(T60) OD SOLENOID CONTROL CIRCUIT SHORT TO OTHER CIRCUITS
(T60) OD SOLENOID CONTROL CIRCUIT OPEN
(T60) OD SOLENOID CONTROL CIRCUIT SHORT TO GROUND
TRANSMISSION SOLENOID/TRS ASSEMBLY
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 Control System uses six electronically controlled solenoids that allow hydraulic fluid to be applied
to various friction elements (clutches), which enables the gear requested. The continuity of each solenoid circuit is
periodically tested. Each inactive solenoid is turned on for a few milliseconds, then off. Each active solenoid is
turned off for a few milliseconds, then on. This pulsing of voltage to the solenoid causes an inductive spike which
can be sensed by the Transmission Control System. If an inductive spike is not sensed by the Transmission Control
System during the continuity check, it is tested again. If the test fails three consecutive times, the appropriate Diag-
nostic Trouble Code (DTC) is set. If the solenoid test is run in response to agear ratio or pressure switch error, one
failure will result in setting the appropriate DTC.Note: This DTC is strictly an electrical fault and does not apply
to any internal transmission failures.
Diagnostic Test
1.RELATED TIPM TCM DTCS PRESENT
With the scan tool, check for TIPM DTCs.
Are there any TIPM TCM DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
2.CHECK TO SEE IF P0760 IS PRESENT
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 Transmission Simulator, Miller tool #8333.
Ignition on, engine not running.
With the scan tool, actuate the OD Solenoid.
When Monitored:
Initially at power-up, then every 10 seconds thereafter. The solenoid circuits will also be tested immediately
after a gear ratio or pressure switch error is detected.
Set Condition:
After three consecutive solenoid continuity test failures, or one failure if test is run in response to a gear ratio
or pressure switch error.Note: This DTC is strictly an electrical fault and does not apply to any internal
transmission failures.
Possible Causes
RELATED TIPM TCM DTCS PRESENT
(T59) UD SOLENOID CONTROL CIRCUIT SHORT TO OTHER CIRCUITS
(T59) UD SOLENOID CONTROL CIRCUIT OPEN
(T59) UD SOLENOID CONTROL CIRCUIT SHORT TO GROUND
TRANSMISSION SOLENOID/TRS ASSEMBLY
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 Control System uses six electronically controlled solenoids that allow hydraulic fluid to be applied
to various friction elements (clutches), which enables the gear requested. The continuity of each solenoid circuit is
periodically tested. Each inactive solenoid is turned on for a few milliseconds, then off. Each active solenoid is
turned off for a few milliseconds, then on. This pulsing of voltage to the solenoid causes an inductive spike which
can be sensed by the Transmission Control System. If an inductive spike is not sensed by the Transmission Control
System during the continuity check, it is tested again. If the test fails three consecutive times, the appropriate Diag-
nostic Trouble Code (DTC) is set. If the solenoid test is run in response to agear ratio or pressure switch error, one
failure will result in setting the appropriate DTC.Note: This DTC is strictly an electrical fault and does not apply
to any internal transmission failures.
Diagnostic Test
1.CHECK FOR TCM TIPM DTCS
With the scan tool under TIPM, check for TCM Power Input DTCs.
Are there any TIPM TCM Power Input DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
2.CHECK IF P0765 IS PRESENT
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 Transmission Simulator, Miller tool #8333.
Ignition on, engine not running.
With the scan tool, actuate the UD Solenoid.
When Monitored:
Initially at power-up, then every 10 seconds thereafter. The solenoid circuits will also be tested immediately
after a gear ratio or pressure switch error is detected.
Set Condition:
After three consecutive solenoid continuity test failures, or one failure if test is run in response to a gear ratio
or pressure switch error.Note: This DTC is strictly an electrical fault and does not apply to any internal
transmission failures.
Possible Causes
RELATED TIPM TCM DTCS PRESENT
(T259) 4C SOLENOID CONTROL CIRCUIT SHORT TO OTHER CIRCUITS
(T259) 4C SOLENOID CONTROL CIRCUIT OPEN
(T259) 4C SOLENOID CONTROL CIRCUIT SHORT TO GROUND
TRANSMISSION SOLENOID/TRS ASSEMBLY
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 Control System uses six electronically controlled solenoids that allow hydraulic fluid to be applied
to various friction elements (clutches), which enables the gear requested. The continuity of each solenoid circuit is
periodically tested. Each inactive solenoid is turned on for a few milliseconds, then off. Each active solenoid is
turned off for a few milliseconds, then on. This pulsing of voltage to the solenoid causes an inductive spike which
can be sensed by the Transmission Control System. If an inductive spike is not sensed by the Transmission Control
System during the continuity check, it is tested again. If the test fails three consecutive times, the appropriate Diag-
nostic Trouble Code (DTC) is set. If the solenoid test is run in response to agear ratio or pressure switch error, one
failure will result in setting the appropriate DTC.Note: This DTC is strictly an electrical fault and does not apply
to any internal transmission failures.
Diagnostic Test
1.CHECK FOR TCM TIPM DTCS
With the scan tool under TIPM, check for TCM Power Input DTCs.
Are there any TIPM TCM Power Input DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
2.CHECK TO SEE IF P0770 IS PRESENT
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 Transmission Simulator, Miller tool #8333.
Ignition on, engine not running.
With the scan tool, actuate the 4C Solenoid.