P1736
P1736-GEAR RATIO ERROR IN 2ND PRIMEFor the Transmission circuit diagram, refer to Wiring Diagram Information.
^ When Monitored:
Continuously with the ignition on, engine running, with the transmission in gear.
^ Set Condition:
If the ratio of the Input RPM to the Output RPM does not match the current gear ratio. 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 MISINSTALLED 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 Pre-Diagnostic Troubleshooting procedure before proceeding. Verification Tests
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 DTC's
Are any Transmission: solenoid, line pressure, speed sensor, or loss of prime DTC's present?
Yes >>Refer to appropriate symptom in the Transmission category. Perform the test for P0944-LOSS OF PRIME first if it is present. P0944
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
No >>Go To 2
2. CHECK EATX DTC EVENT DATA
With the scan tool, read and record the EATX DTC EVENT DATA.
NOTE: Make sure to record all EATX DTC EVENT DATA stored in the scan tool for future reference in this test procedure.
Does the EATX DTC EVENT DATA display information for the DTC P1736?
Yes >>Go To 3
No >>Go To 6
3. CHECK RPM IN EATX DTC EVENT DATA
Refer to the EATX DTC EVENT DATA recorded earlier.
Does the Input RPM read zero?
Yes >>Check the input speed sensor and wiring. Refer to test P0715 and diagnose as if the DTC is current. P0715
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
No >>Go To 4
4. CHECK LINE PRESSURE READING
Refer to the EATX DTC EVENT DATA recorded earlier.
Is the line pressure reading more than 10 psi below the desired line pressure?
Yes >>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?
Yes >>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 procedure.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
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. Verification Tests
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 detect a faulty UD clutch.
Did the clutch test pass, did the Input Speed remain at zero?
Yes >>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 perform a wiggle test using the Transmission Simulator, Miller tool #8333.
Were there any problems found?
Yes >>Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
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 from 4th to 2nd (prime) gears.
Is there an obvious slippage noticed in 4th or 2nd prime gears, or runaway on the 4-2 shift?
Yes >>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 hydraulic circuit?
Yes >>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. Verification Tests
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?
Yes >>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. Verification Tests
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 4C clutch and/or excessive air leakage in the 4C clutch hydraulic circuit?
Yes >>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. Verification Tests
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
Yes >>Repair as necessary. Refer to the Service Information for proper repair procedures.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
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 Manual Lever 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?
Yes >>Replace the Transmission Solenoid/TRS Assembly per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
No >>Replace the reaction carrier per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
14. CHECK IF DTC RESET
Did the DTC P1736 reset during the road test?
Yes >>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 O-ring.
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 the Solenoid 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. Verification Tests
16. INTERMITTENT DTC
The conditions necessary to set this DTC are not present at this time.
Use the EATX 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?
Yes >>Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
No >>Test Complete.