P0732
P0732-GEAR RATIO ERROR IN 2ND
For a complete wiring diagram, refer to the Wiring Information.
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 and P1736).
2) An excessive change in input or output speeds indicating signal intermittent may result in the DTCs P0716 and/or P0721 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 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 Monitored:
Continuously with the ignition on, engine running, and after the transmission has achieved the proper gear ratio.
- 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
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure
1. CHECK FOR RELATED DTCS
1. With the scan tool, check for other transmission DTCs.
Are there any Transmission solenoid, line pressure, speed sensor, and/or loss of prime DTCs present?
Yes
- Perform the appropriate diagnostic procedure. Perform the test for P0944-LOSS OF PRIME first if it is present. P0944
No
- Go To 2
2. CHECK IF DTC IS CURRENT
1. With the scan tool, read and record the Event Data.
NOTE: Make sure to record all Event Data stored in the scan tool for future reference in this test procedure.
Does the Event Data display information for the DTC P0732?
Yes
- Go To 4
No
- Go To 3
3. CHECK EVENT DATA
In the Event Data recorded earlier, does the Event Data display information for the DTC P1790, with target gear = 2nd, or with both 2C and UD clutches applying?
Yes
- Go To 4
No
- Go To 7
4. CHECK RPM IN EVENT DATA
In the Event Data recorded earlier, does the Input rpm read zero?
Yes
- Check the input speed sensor and wiring. Perform diagnostic test P0716 and diagnose as if the DTC is current. P0716
No
- Go To 5
5. CHECK LINE PRESSURE READING
In the Event Data recorded earlier, is the line pressure reading more than 10 psi below the desired line pressure?
Yes
- Go To 6
No
- Go To 7
6. CHECK TRANSMISSION OIL FILTER
1. Turn the ignition off to the lock position.
2. Remove and inspect the Transmission Oil Pan for excessive debris.
3. Remove and inspect the Primary Oil Filter.
NOTE: Make sure the Primary Transmission Oil Filter and seal are properly installed and are not cracked or split.
Does the Oil Pan contain excessive debris and/or is the Primary Oil Filter cracked, plugged or mis-installed?
Yes
- Repair the plugged, cracked, or split Primary Transmission Oil Filter and/or seal. If excessive clutch debris is present, check the clutches for damage. Refer to the Service Information for the proper hydraulic clutch repair procedure.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
No
- Remove the Transmission Oil Pump. 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 the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
7. CHECK IF THE DTC P0732 IS CURRENT
1. With the scan tool, perform the 2nd Gear Clutch Test. Follow the instructions on the scan tool.
2. Increase the throttle angle, TPS Degree, to 30° for no more than a few seconds.
CAUTION: Do not overheat the transmission.
NOTE: If the 2C clutch is faulty, the overrunning clutch will hold and the slip test will pass. The 2nd gear clutch test will not detect a faulty 2C clutch. However, it will detect a faulty UD clutch.
Did the clutch test pass, did the Input Speed remain at zero?
Yes
- Go To 8
No
- Go To 10
8. CHECK FOR INTERMITTENT OPERATION
1. Check the Shifter adjustment.
2. Intermittent gear ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed Sensor Ground circuit.
3. Check the Speed Sensor wiring and connectors for good connection, then perform a wiggle test using the Transmission Simulator, Miller tool #8333A.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
No
- Go To 9
9. CHECK FOR SLIPPAGE
1. With the scan tool, erase Transmission DTCs.
2. Road test the vehicle.
Is there an obvious slippage noticed in 2nd gear, or runaway on the 1-2 shift?
Yes
- Go To 12
No
- Go To 15
10. CHECK THE UD HYDRAULIC CLUTCH CIRCUIT
1. Remove Transmission Oil Pan and check for excessive debris.
2. Remove the Valve Body and air check the UD hydraulic clutch circuit (in the case).
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, reaction shaft support seal rings and the dribbler assembly, and the flatness of the pump valve body and pump housing faces. Check main regulator valve for sticking in the bore.
NOTE: If the UD clutch has failed but no obvious cause is found (such as a cut piston seal, broken seal ring, stuck regulator valve or any other items listed above) replace the Transmission Solenoid/TRS Assembly in addition to any necessary internal repairs.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
No
- Go To 11
11. CHECK THE UD ACCUMULATOR PISTON
1. 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.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
No
- Replace Transmission Solenoid/TRS Assembly. Transmission Solenoid and TRS Assembly - Removal
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
12. CHECK FOR EXCESSIVE DEBRIS
1. Remove the Transmission Oil Pan and check for excessive debris.
2. If grey sludge is present, check for a improperly assembled 2C clutch with the thick reaction plate not against the case.
3. Remove the valve body and air check the 2C hydraulic clutch circuit (in the 2C/4C clutch retainer).
NOTE: The 2C clutch passage contains a small bleed orifice, a small amount of air leakage is normal.
Were there any problems found, excessive debris, improperly assembled 2C clutch and/or excessive air leakage in the 2C hydraulic clutch circuit?
Yes
- Repair as necessary. Refer to the Service Information for proper repair procedures. Note: Check the 2C piston seals and bleed orifice.
NOTE: If the 2C clutch has failed but no obvious cause is found (such as a cut piston seal, stuck regulator valve or any other items listed above) replace the Transmission Solenoid/TRS Assembly in addition to any necessary internal repairs.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
No
- Go To 13
13. CHECK THE 2C ACCUMULATOR
1. Check the 2C Accumulator piston for cracks or a cut seal.
2. Check for a cut or missing No. 7 or No. 5 check ball.
3. 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 the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
No
- Go To 14
14. CHECK FOR BROKEN REVERSE SUN GEAR WELD
1. Working through the windows in the bottom of the case, check for a broken Reverse Sun gear weld to the reaction carrier as follows:
- Hold the Transmission Output Shaft by holding the Transmission Manual Lever in the park position.
- Rotate the Input Annulus gear and drive shell (the drum that encloses the two rearmost carriers).
- Check to see if the reaction carrier (the front-most carrier, whose outer shell is splined to the 2C clutch) is rotating faster than the drive shell is being turned.
Is the reaction carrier turning faster than the drive shell?
Yes
- Replace Transmission Solenoid/TRS Assembly. Transmission Solenoid and TRS Assembly - Removal.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
No
- Replace the reaction carrier.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
15. CHECK IF THE DTC RESETS
Did the DTC P0732 reset during the road test?
Yes
- Go To 16
No
- Go To 17
16. LIST OF POSSIBLE CAUSES
1. If any other DTCs set during the road test, refer to the appropriate test in the Transmission category.
2. If no other DTCs 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 mis installed Primary Transmission Oil Filter and/or seal.
- Check for cut and/or missing No. 7 and No. 5 check balls in the main valve body.
- Check the 2C 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 dribbler assembly.
- Check the 2C clutch piston seals, and bleed orifice.
- Check the main regulator valve for sticking in its bore and the flatness of the pump valve body and pump housing faces.
- Check for a improperly assembled 2C clutch with the thick reaction plate not against the case.
View repair
Repair
- Repair as necessary. Refer to the Service Information for proper repair procedures.
NOTE: If the UD or 2C clutch has failed but no obvious cause is found (such as a cut piston seal, broken seal ring, stuck regulator valve or any other items listed above) replace the Transmission Solenoid/TRS Assembly in addition to any necessary internal repairs.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
17. INTERMITTENT DTC
1. The conditions to set this DTC are not currently present.
2. With the scan tool, check the Event Data to help identify the conditions in which the DTC was set.
- If the Event Data shows fault P0732 was set in Park, Reverse, or Neutral, replace the Powertrain Control Module.
- If the Event Data shows fault P0732 set with input rpm = zero, check the input speed sensor and related wiring.
- If the Event Data shows fault P0732 set with line pressure significantly below desired line pressure, check for the cause of low line pressure (i.e., oil level, mis installed or damaged primary filter or filter seal, sticking main regulator valve in pump, etc.).
- If the Event Data shows fault P0732 set with the UD or 2C pressure switch open (but line pressure matches Desired Line Pressure), air check the UD and 2C hydraulic clutch circuits for leakage. If the UD and 2C hydraulic clutch circuits are OK, replace the Transmission Solenoid/TRS assembly.
3. Check the gearshift linkage adjustment.
4. Intermittent Gear Ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed Sensor Ground circuit.
5. Remove the Starter Relay.
CAUTION: Removal of the Starter Relay will prevent the vehicle from being started in gear.
WARNING: The Starter Relay must be removed from the PDC. Failure to do so may result in possible serious or fatal injury.
NOTE: Failure to remove the Starter Relay can cause a Transmission - No Response condition.
6. Install Transmission Simulator 8333A.
7. Wiggle wiring and connectors while checking for intermittent operation with the Transmission Simulator.
8. Gear ratio DTCs can also be set under extreme temperature conditions.
9. Verify if the problem is only experienced under extreme hot or cold conditions.
Were there any problems found.
Yes
- Repair as necessary.
- Perform the 45RFE/545RFE TRANSMISSION VERIFICATION TEST. . 545RFE Transmission Verification Test
No
- Test Complete.