14.CHECK THE (T48) 4C PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (T48) 4C Pressure
Switch Sense circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (T48) 4C Pressure Switch Sense circuit for a
short to ground.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1.
No>>
Replace the Powertrain Control Module per the Service
Information. With the scan tool, perform the QUICK LEARN
procedure.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
15.CHECK IF THE #5 AND/OR #7 CHECK BALL IS CUT OR DAMAGED
Turn the Ignition off to the lock position.
Remove the Valve Body Assembly per the Service Information.
Inspect the #5 and #7 check balls for any cuts or damage.
Inspect the 4C accumulator piston and seals and also the 4C tower seal on topof the valve body. Refer to the
Service Information.
Where there any problems found?
Ye s>>
Repair as necessary. Check for excessive clutch debris in the transmission oil pan. If excessive clutch
debris is present, repair 4C clutch as necessary. Refer to the Service Information for proper repair pro-
cedures.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 16
16.CHECK FOR EXCESSIVE LEAKAGE WITHIN THE 4C CLUTCH CIRCUIT
Air check the 4C Clutch hydraulic circuit. Refer to the Service Information.
NOTE: This hydraulic clutch circuit contains a small bleed orifice. Smallleakage is considered normal.
Was there excessive air leakage in the 4C Clutch hydraulic circuit?
Ye s>>
Repair as necessary. Refer to the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Replace the Transmission Solenoid/TRS Assembly per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
P1736-GEAR RATIO ERROR IN 2ND PRIME
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
RELATED DTC’S PRESENT
INPUT SPEED SENSOR OR WIRING
LOW FLUID LEVEL
CRACKED OR MIS-INSTALLED PRIMARY OIL FILTER OR SEAL
WORN SOLENOID SWITCH VALVE OR PLUGS
STUCK OR STICKING MAIN REGULATOR VALVE
BURNED UD OR 4C CLUTCH
CUT 4C OR UD PISTON SEAL
BROKEN 4C PISTON CASTING
BROKEN OR MISSING 4C BLEED ORIFICE
BROKEN OR MISSING UD BLEED ORIFICE
CUT 4C OR UD ACCUMULATOR PISTON SEAL
CRACKED 4C OR UD ACCUMULATOR PISTON
EXTRA CHECK BALL IN PASSAGE DOWNSTREAM OF #7 CHECK BALL POCKET
TRANSMISSION SOLENOID/TRS ASSEMBLY
BROKEN WELD - REACTION CARRIER TO REVERSE SUN GEAR
MISSING TEETH ON INPUT CLUTCH HUB TONE WHEEL
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.DETERMINING IF RELATED DTC’S ARE PRESENT
With the scan tool, check for other transmission DTCs.
Are any Transmission: solenoid, line pressure, speed sensor, or loss of primeDTCspresent?
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
2.CHECK DTC EVENT DATA
With the scan tool, read and record the DTC EVENT DATA.
NOTE: Make sure to record all DTC EVENT DATA stored in the scan tool for future reference in this test
procedure.
Does the DTC EVENT DATA display information for the DTC P1736?
Ye s>>
Go To 3
No>>
Go To 6
3.CHECK RPM IN DTC EVENT DATA
Refer to the DTC EVENT DATA recorded earlier.
Does the Input RPM read zero?
Ye s>>
Check the input speed sensor and wiring. Refer to test P0715 and diagnose asif the DTC is current.
No>>
Go To 4
4.CHECK LINE PRESSURE READING
Refer to the DTC EVENT DATA recorded earlier.
Isthelinepressurereadingmorethan10 psi below the desired line pressure?
Ye s>>
Go To 5
No>>
Go To 6
5.PLUGGED TRANSMISSION OIL FILTER
Turn the ignition off to the lock position.
Remove and inspect the Transmission Oil Pan for excessive debris per the Service Information.
Remove and inspect the Primary Oil Filter per the Service Information.
NOTE: Make sure the Primary Transmission Oil Filter and/or seal is not cracked or split.
Does the Oil Pan contain excessive debris and/or is the Primary Oil Filter cracked or plugged?
Ye s>>
Repair the plugged, cracked, or split Primary Transmission Oil Filter and/or seal. If the Primary Trans-
mission Oil Filter is plugged, refer to the Service Information for the proper hydraulic clutch repair pro-
cedure.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Remove the Transmission Oil Pump per the Service Information. Check the main Regulator Valve for
sticking in its bore, scoring, and/or damage and clean and repair as necessary. If no problem is found,
replace the Transmission Solenoid/TRS Assembly.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
6.CHECK TO SEE IF DTC P1736 IS CURRENT
With the scan tool, perform the 2nd Prime Gear Clutch Test. Follow the instructions on the scan tool.
Increase the throttle angle, TPS Degree, to 30° for no more than a few seconds.
CAUTION: Do not overheat the transmission.
NOTE: If the 4C clutch is faulty, the overrunning clutch will hold and the slip test will pass. The 2nd Prime
Gear Clutch Test will not detect a faulty 4C clutch. However, it will detectafaultyUDclutch.
Did the clutch test pass, did the Input Speed remain at zero?
Ye s>>
Go To 7
No>>
Go To 9
7.CHECK FOR INTERMITTENT OPERATION
Check the Shifter adjustment per the Service Information.
Intermittent gear ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed
Sensor Ground circuit.
Check the Speed Sensor wiring and connectors for good connection, then performawiggletestusingtheTrans-
mission Simulator, Miller tool #8333.
Were 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>>
Go To 8
8.CHECK FOR SLIPPAGE
With the scan tool, erase Transmission DTCs.
Road test the vehicle.
During the road test, operate in 4th gear, and perform kickdown shifts from4th to 2nd (prime) gears.
Is there an obvious slippage noticed in 4th or 2nd prime gears, or runaway onthe 4-2 shift?
Ye s>>
Go To 11
No>>
Go To 14
9.UD CLUTCH HYDRAULIC CIRCUIT
Remove Transmission Oil Pan and check for excessive debris.
Remove the Valve Body and air check the UD clutch hydraulic circuit (in the case) per the Service Information.
NOTE: The UD clutch passage contains a small bleed orifice, a small amount of air leakage is normal.
Were there any problems found, excessive debris and/or excessive air leakage in the UD clutch hydrau-
lic circuit?
Ye s>>
Repair as necessary. Check the UD clutch piston seals and the dribbler assembly, reaction shaft sup-
port seal rings, and the flatness of the pump valve body and pump housing faces. Check main regulator
valve for sticking in the bore.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 10
10.UD ACCUMULATOR PISTON
Check the UD bleed orifice, accumulator piston, and accumulator piston seal in the main valve body.
Were there any problems found?
Ye s>>
Repair as necessary. Refer to the Service Information for proper repair procedures.
No>>
Replace the Transmission Solenoid/TRS Assembly per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
11 .EXCESSIVE DEBRIS
Remove the Transmission Oil Pan and check for excessive debris.
Remove the valve body and air check the 4C clutch hydraulic circuit per the Service Information.
NOTE: The 4C clutch passage contains a small bleed orifice, a small amount of air leakage is normal.
Were there any problems found, excessive debris, improperly assembled 4Cclutch and/or excessive air
leakage in the 4C clutch hydraulic circuit?
Ye s>>
Repair as necessary. Refer to the Service Information for proper repair procedures. Note: Check the 4C
piston seals and bleed orifice.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 12
12.4C ACCUMULATOR
Check the 4C Accumulator piston for cracks or a cut seal.
Check for a cut or missing #7 or #5 check balls.
Check the Solenoid Switch Valve and its plugs for sticking in its bore or excessive wear.
Were there any problems found
Ye s>>
Repair as necessary. Refer to the Service Information for proper repair procedures.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 13
13.CHECK FOR BROKEN REVERSE SUN GEAR WELD
Working through the windows in the bottom of the case, check for a broken Reverse Sun gear weld to the reaction
carrier as follows:
(1) Hold the Transmission Output Shaft by holding the Transmission ManualLever in the park position.
(2) Rotate the Input Annulus gear and drive shell, (the drum that encloses the two rearmost carriers).
(3) Check to see if the reaction carrier (the front most carrier, whose outer shell is splined to the 4C clutch) is
rotating faster than the drive shell is being turned.
Is the reaction carrier turning faster than the drive shell?
Ye s>>
Replace the Transmission Solenoid/TRS Assembly per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Replace the reaction carrier per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
14.CHECK IF DTC RESET
Did the DTC P1736 reset during the road test?
Ye s>>
Go To 15
No>>
Go To 16
15.LIST OF POSSIBLE CAUSES
If any other DTC’s set during the road test, refer to the appropriate symptom in the Transmission category.
If no other DTC’s set during the road test, below is a list of possible causes, but not strictly limited to those:
Check for excessive debris in the Transmission Oil pan, plugged, cracked,or split Primary Transmission Oil Filter
and/or seal.
Check for cuts or missing #7 and #5 check balls in the main valve body.
Check the 4C and UD accumulator pistons and seals, UD bleed orifice, and theSolenoid Switch Valve and Plugs
in the main valve body.
Check the UD clutch piston seals, reaction shaft support seal rings, and the flatness of the pump valve body and
pump housing faces.
Check the 4C clutch piston seals, and bleed orifice.
Check the UD clutch piston seals, reaction shaft support seal rings, and dribbler assemblies, and the flatness of the
pump valve body and pump housing faces.
View repair
Repair
Repair as necessary. Refer to the Service Information for proper repair procedures.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
16.INTERMITTENT DTC
The conditions necessary to set this DTC are not present at this time.
Use the DTC EVENT DATA to help identify the conditions and/or possible causes that may have caused the DTC
to set.
Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.
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 .
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 switchtoL/R.
With the scan tool, monitor the L/R Pressure Switch state while pressing thePressureSwitchTestbuttononthe
Transmission Simulator.
Did the state of the L/R Pressure Switch change while pressing the PressureSwitch Test button?
Ye s>>
Go To 4
No>>
Go To 5
4.CHECK IF THE SOLENOID SWITCH VALVE STICKING
Turn the ignition off to the lock position.
Remove the Transmission Oil Pan per the Service Information.
Remove the Transmission Valve body per the Service Information.
Inspect the Solenoid Switch Valve and Plugs for sticking.
Is the Solenoid Switch Valve or Plugs sticking?
Ye s>>
Clean and inspect per the Service Information. Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Replace the Transmission Solenoid/TRS Assembly per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
5.CHECK THE L/R PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid/TRS Assembly harness connec-
tor.
Disconnect all PCM harness connectors.
Measure the resistance between the (T50) L/R Pressure Switch Sense
circuit and all other circuits in the Transmission Solenoid/TRS Assembly
harness connector.
Is the resistance below 5.0 ohms between the (T50) L/R Pres-
sure Switch Sense circuit and all other circuit(s) in the Trans-
mission Solenoid/TRS Assembly harness connector?
Ye s>>
Repair the (T50) L/R PressureSwitch Sense circuit for a
short to another circuit(s).
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
3.L/R CLUTCH CIRCUIT LEAKS IN THE VALVE BODY
Turn the ignition off to the lock position.
Remove the transmission oil pan per the Service Information.
Remove the valve body per the service information.
Check condition of the L/R accumulator springs.
Look for possible leak paths into the L/R clutch hydraulics circuit withinthe valve body.
Were 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>>
Go To 4
4.AIR CHECK L/R CLUTCH CIRCUITS
Perform an air check on the L/R Clutch circuit per the Service Information.
Watch and listen for L/R Clutch piston movement.
Does the L/R piston stroke and return properly?
Ye s>>
Replace the Transmission/TRS Solenoid Assembly per the service information. With the scan tool, per-
form Quick Learn.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Repair internal transmission as necessary. Pay attention to the components related to the L/R clutch. A
broken or weak L/R clutch return spring, Accumulator Spring, and/or dislocated snap ring could cause
this problem.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
5.VERIFY PCM OPERATION
NOTE: The TRANS TEMP DEG must be at least 43° C or 110° F before performing thefollowing steps.
Perform eight learnable starts. A learnable start is defined as follows: Start engine. From a standstill, accelerate
lightly to 80 Kmh or 50 MPH, then brake lightly to a stop. Turn off engine.
With the scan tool, record the CL VOL INDEX (CVI) for all clutches
With the scan tool, perform a BATTERY DISCONNECT.
With the scan tool, read the CVI’s and compare them to the readings recordedbefore the BATTERY DISCONNECT.
Are any of the CVI’s less than 5 or different than before the BATTERY DISCONNECT?
Ye s>>
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)
No>>
Te s t C o m p l e t e .