545RFE Automatic Transmission
P0732-GEAR RATIO ERROR IN 2ND
For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams
- 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
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 45RFE/545RFE Pre-Diagnostic Troubleshooting 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 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.
Diagnostic Test
1. DETERMINING IF RELATED DTC'S ARE PRESENT
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?
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. 45RFE/545RFE Transmission Verification Test
No
- Go To 2
2. CHECK IF DTC IS CURRENT
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 P0732?
Yes
- Go To 4
No
- Go To 3
3. CHECK EATX DTC EVENT DATA
In the EATX DTC EVENT DATA, identify the DTC that was recorded earlier.
Does the EATX DTC 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 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. P0716
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
No
- Go To 5
5. 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 6
No
- Go To 7
6. CHECK TRANSMISSION OIL FILTER
Turn the ignition off to the lock position.
Remove and inspect the Transmission Oil Pan for excessive debris.
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 misinstalled?
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.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/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 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
7. CHECK TO SEE IF DTC P0732 IS CURRENT
With the scan tool, perform the 2nd 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 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
Check the Shifter adjustment.
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. 45RFE/545RFE Transmission Verification Test
No
- Go To 9
9. CHECK FOR SLIPPAGE
With the scan tool, erase Transmission DTCs.
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. UD HYDRAULIC CLUTCH CIRCUIT
Remove Transmission Oil Pan and check for excessive debris.
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.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
No
- Go To 11
11. 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.
No
- Replace the Transmission Solenoid/TRS Assembly.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
12. EXCESSIVE DEBRIS
Remove the Transmission Oil Pan and check for excessive debris.
If grey sludge is present, check for a improperly assembled 2C clutch with the thick reaction plate not against the case.
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.
Note: Check the 2C piston seals and bleed orifice.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
No
- Go To 13
13. 2C ACCUMULATOR
Check the 2C 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.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
No
- Go To 14
14. 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 frontmost 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 the Transmission Solenoid/TRS Assembly.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
No
- Replace the reaction carrier.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
15. CHECK IF DTC RESET
Did the DTC P0732 reset during the road test?
Yes
- Go To 16
No
- Go To 17
16. 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 misinstalled Primary Transmission Oil Filter and/or seal.
- Check for cut and/or missing #7 and #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.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
17. INTERMITTENT DTC
The conditions to set this DTC are not currently present.
With the scan tool, check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set.
- If the DTC Event Data shows fault P0732 was set in Park, Reverse, or Neutral, replace the Powertrain Control Module.
- If the DTC Event Data shows fault P0732 set with input RPM = zero, check the input speed sensor and related wiring.
- If the DTC 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, misinstalled or damaged primary filter or filter seal, sticking main regulator valve in pump, etc.).
- If the DTC 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.
Check the gearshift linkage adjustment.
Intermittent Gear Ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed Sensor Ground circuit.
Remove the Starter Relay.
NOTE: Failure to remove the Starter Relay can cause a Transmission - No Response condition.
Install Transmission Simulator, Miller tool #8333.
Wiggle wiring and connectors while checking for intermittent operation with the Transmission Simulator.
Gear ratio DTC's can also be set under extreme temperature conditions.
Verify if the problem is only experienced under extreme hot or cold conditions.
Were there any problems found.
Yes
- Repair as necessary.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. 45RFE/545RFE Transmission Verification Test
No
- Test Complete.