P0735-GEAR RATIO ERROR IN 5TH

For a complete wiring diagram Refer to Section 8W

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

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 Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - DIAGNOSIS AND TESTING) .

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
If any of these DTC's are present, perform their respective tests first.

Are there any Transmission; solenoid, line pressure, speed sensor, and/or loss of prime DTC's present?

Yes

Refer to the Transmission category and perform the appropriate symptom. If any of these DTCs are present, they may cause a Speed Ratio Error. Perform the test for P0944 first if it is present.

Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)

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 P0735?

Yes

Go To 4

Go To 3

3. CHECK TARGET GEAR

In the DTC EVENT DATA recorded earlier, does the DTC EVENT DATA show the DTC P1790, with Target gear = 5th, or with both the 2C and OD clutches applying?

Yes

Go To 4

Go To 6

4. CHECK INPUT RPM

In the DTC EVENT DATA recorded earlier, does the Input RPM read zero?

Yes

Refer to the Transmission category and perform the diagnostic procedure for P0715 (Input Speed Sensor Error). Diagnose the DTC as if it is set and current.

Go To 5

5. CHECK LINE PRESSURE READING

In the DTC EVENT DATA recorded earlier, is the line pressure reading more than 10 PSI below the desired line pressure reading?

Yes

Remove the Transmission Oil pan and check the Transmission Oil filter for improper installation or plugged, if Primary oil filter is OK, check the main regulator valve in pump. If excessive debris is in the oil pan, check clutches and repair as necessary. Refer to the Service Information for proper repair procedures.

Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)

Go To 6

6. CHECK TRANSMISSION FOR SLIPPAGE

Erase DTCs and road test the vehicle.
Check the transmission operation in reverse and all forward gears.

During the road test, was there any obvious slippage noted in 5th gear or a runaway during the 4–5 shift?

Yes

Go To 8

Go To 7

7. CHECK IF DTC RESET

With the scan tool, check for Transmission DTCs after the road test.

Did the DTC P0735 reset?

Yes

Go To 8

Test Complete.

8. CHECK INTERNAL TRANSMISSION

Remove the Transmission Oil Pan and Valve Body, per the Service Information, and check for the following:
— Excessive clutch and or metal debris in the oil pan.
— If the accumulator cover is intact and the 2C tower seal is not cut or split.
— OD and 2C accumulator pistons for cracks or cut seals.
— Solenoid Switch Valve and its plugs for stickiness or wear.
— Cut or missing #5, #6, or #7 check ball.
— OD bleed orifice on top of the valve body.
— Air check the OD and 2C hydraulic clutch circuits for excessive leakage. Refer to the Service information.

NOTE: Both the OD and 2C hydraulic clutch circuits contain a small bleed orifice. A small amount of air leakage is considered normal. The OD hydraulic clutch circuit bleed orifice connects to the Reverse input clutch hydraulic cavity. A small amount of air leakage into the Reverse hydraulic clutch circuit is considered normal.

Were there any problems found?

Yes

Repair as necessary. Refer to the Service Information for proper repair procedures.

Replace the Transmission Solenoid/TRS Assembly per the Service Information.