Code No.41 (1st), 42 (2nd), 43 (3rd), 44 (4th), 46 (reverse): Gear incorrect ratio
OPERATION
The engine-A/T-ECU detects the current gear/speed according to the output signals from the input and output shaft speed sensor.
DIAGNOSIS CODE SET CONDITIONS
If the output from the output shaft speed sensor multiplied by the gear ratio is not the same as the output from the input shaft speed sensor after completing of shifting, the corresponding diagnosis code is set.
If each diagnosis code is set 4 times, the transmission is fixed in 3rd as a fail-safe measure.
PROBABLE CAUSES
- Malfunction of input shaft speed sensor
- Malfunction of output shaft speed sensor
- Damaged harness wires and connectors
- Malfunction of the engine-A/T-ECU
- Malfunction of solenoid valve
- Malfunction of underdrive clutch retainer
- Malfunction of valve body
- Malfunction of transfer drive gear or driven gear
- Malfunction of low-reverse brake system (for diagnosis codes 41, 46)
- Malfunction of underdrive clutch system (for diagnosis codes 41, 42, 43)
- Malfunction of second brake system (for diagnosis codes 42, 44)
- Malfunction of overdrive clutch system (for diagnosis codes 43, 44)
- Malfunction of reverse clutch system (for diagnosis code 46)
- Malfunction of one-way clutch system (for diagnosis code 41)
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STEP 1. M.U.T.-III diagnosis code
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Either of diagnosis codes 41, 42, 43, 44 or 46 is set, the input shaft speed sensor or output shaft speed sensor is defective.
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Q.
Are diagnosis codes 22 or 23 set?
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YES <diagnosis code 22 is set> : Refer to diagnosis code 22 input shaft speed sensor system  .
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YES <diagnosis code 23 is set> : Refer to diagnosis code 23 output shaft speed sensor system .
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 Go to Step 2.
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STEP 2. M.U.T.-III diagnosis code
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Either of diagnosis codes 41, 42, 43, 44 or 46 is set, the corresponding solenoid valve is defective.
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Q.
Is either of diagnosis code 31, 32, 33, 34 set?
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YES <diagnosis code 31 is set> : Refer to diagnosis code 31: Low-reverse solenoid valve system .
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YES <diagnosis code 32 is set> : Refer to diagnosis code 32: Underdrive solenoid valve system .
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YES <diagnosis code 33 is set> : Refer to diagnosis code 33: Second solenoid valve system .
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YES <diagnosis code 34 is set> : Refer to diagnosis code 34: Overdrive solenoid valve system .
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Go to Step 3.
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STEP 3. Hydraulic pressure test
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Each hydraulic pressure of the elements below, which diagnosis codes indicate, should be within the standard value.
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- diagnosis code 41: Underdrive clutch, low-reverse brake
- diagnosis code 42: Underdrive clutch, second brake
- diagnosis code 43: Underdrive clutch, overdrive clutch
- diagnosis code 44: Overdrive clutch, second brake
- diagnosis code 46: Reverse clutch, low-reverse brake
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OK: Refer to Hydraulic Pressure Test .
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Q.
Is the check result normal?
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 Go to Step 6.
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NO <some hydraulic pressures are abnormal> : Go to Step 5.
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NO <all hydraulic pressure are abnormal> : Go to Step 4.
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STEP 4. Adjust the line pressure and recheck the diagnosis code.
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(1)Adjust the line pressure (Refer to ).
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(2)Test drive the vehicle.
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(3)Check the diagnosis code.
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Q.
Is the diagnosis code set?
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Go to Step 5.
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The inspection is complete.
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STEP 5. Disassemble, clean and assemble the valve body and recheck the diagnosis code.
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(1)Check the mounting bolts for looseness, and the O-ring, solenoid valve and valve body for damage.
Replace the valve body assembly if the damages are thought to be irreparable.
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(2)Test drive the vehicle.
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(3)Check the diagnosis code.
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Q.
Is the diagnosis code set?
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Go to Step 7.
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The inspection is complete.
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STEP 6. Replace the engine-A/T-ECU and then recheck the diagnosis code.
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(1)Replace the engine-A/T-ECU.
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(2)Test drive the vehicle.
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(3)Check the diagnosis code.
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Q.
Is the diagnosis code set?
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Go to Step 7.
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The inspection is complete.
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STEP 7. Check the A/T internal clutch and brake, and then recheck the diagnosis code.
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(1)Check the following clutches or brakes according to the output diagnosis codes, replace if necessary.
- If diagnosis code 41, 42, 43 are set individually or in a group, replace the underdrive clutch.
- If diagnosis code 43, 44 are set individually or in a group, replace the overdrive clutch.
- If diagnosis code 46 is set, replace the reverse clutch.
- If diagnosis code 41, 46 are set individually or in a group, replace the low-reverse brake.
- If diagnosis code 42, 44 are set individually or in a group, replace the second brake.
- If diagnosis code 41 is set, replace the one-way clutch.
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(2)Test drive the vehicle.
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(3)Check the diagnosis code.
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Q.
Is the diagnosis code set?
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Eliminate the cause of the noise.
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The inspection is complete.
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