P0733

DTC 43 (P0733): 3rd Gear Incorrect Ratio

Part 1 Of 2:

Part 2 Of 2:

CIRCUIT OPERATION
^ The input shaft speed sensor generates a pulsed signal of 0 <-> 5 volts. The pulsed signal frequency increases with an increase in the input shaft speed.
^ The PCM (terminal 103) continuously monitors the input shaft speed signal.
^ The output shaft speed sensor generates a pulsed signal of 0 <-> 5 volts. The pulsed signal frequency increases with an increase in the output shaft speed.
^ The PCM (terminal 104) continuously monitors the output shaft speed signal.

DESCRIPTIONS OF MONITOR METHODS
In 1st gear, if a difference between turbine revolution and that value calculated from output revolution equals or exceeds specified value, PCM judges that step-out in 1st gear has occurred.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored)
^ DTC 27, 28 (P0705): Transmission range switch malfunction
^ DTC 22 (P0715): Input shaft speed sensor malfunction
^ DTC 23 (P0720): Output shaft speed sensor malfunction
^ DTC 36 (P0743): Torque converter clutch solenoid malfunction
^ DTC 31 (P0753): Low-reverse solenoid malfunction
^ DTC 32 (P0758): Underdrive solenoid malfunction
^ DTC 33 (P0763): Second solenoid malfunction
^ DTC 34 (P0768): Overdrive solenoid malfunction
^ DTC 54 (P1751):A/T control relay malfunction
Sensor (The sensor is determined to be normal)
^ Input shaft speed sensor
^ Output shaft speed sensor
^ Transmission range switch
^ Torque converter clutch solenoid
^ Low-reverse solenoid
^ Underdrive solenoid
^ Second solenoid
^ Overdrive solenoid
^ A/T control relay





LOGIC FLOW CHARTS (Monitor Sequence)

DTC SET CONDITIONS
Check Conditions
^ Engine speed: 450 r/min or more.
^ Output speed: 350 r/min or more.
^ Shift stage: 1st gear.
^ Input speed: more than 0 r/min.
^ Transmission fluid temperature sensor voltage: 4.5 volts or less.
^ Voltage of battery: 10 volts or more.
^ Transmission range switch rationality: only one signal.
^ Time after shift changing finish: 2 seconds or more.

Judgement Criteria
^ Output speed: [(input speed - 200 r/min) / 1st gear ratio] or less. (4 seconds)

DESCRIPTIONS OF MONITOR METHODS
In 2nd gear, if a difference between turbine revolution and that value calculated from output revolution equals or exceeds specified value, PCM judges that step-out in 2nd gear has occurred.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored)
^ DTC 27, 28 (P0705): Transmission range switch malfunction
^ DTC 22 (P0715): Input shaft speed sensor malfunction
^ DTC 23 (P0720): Output shaft speed sensor malfunction
^ If DTC 41 (P0731) is set consecutively four times, the transaxle is locked into 3rd gear as a fail-safe measure, and the "N" range light flashes once per second.

OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive at 20 km/h (12 mph) or more for 10 seconds, with 1st gear fixed (L range or 1st gear in sport mode).
^ DTC 36 (P0743): Torque converter clutch solenoid malfunction
^ DTC 31 (P0753): Low-reverse solenoid malfunction
^ DTC 32 (P0758): Underdrive solenoid malfunction
^ DTC 33 (P0763): Second solenoid malfunction
^ DTC 34 (P0768): Overdrive solenoid malfunction
^ DTC 54 (P1751): A/T control relay malfunction
Sensor (The sensor is determined to be normal)
^ Input shaft speed sensor
^ Output shaft speed sensor
^ Transmission range switch
^ Torque converter clutch solenoid
^ Low-reverse solenoid
^ Underdrive solenoid
^ Second solenoid
^ Overdrive solenoid
^ A/T control relay





LOGIC FLOW CHARTS (Monitor Sequence)

DTC SET CONDITIONS
Check Conditions
^ Engine speed: 450 r/min or more.
^ Output speed: 500 r/min or more.
^ Shift stage: 2nd gear.
^ Input speed: more than 0 r/min.
^ Transmission fluid temperature sensor voltage: 4.5 volts or less.
^ Voltage of battery: 10 volts or more.
^ Transmission range switch rationality: only one signal.
^ Time after shift changing finish: 2 seconds or more.

Judgement Criteria
^ Output speed: [(input speed + 200 r/min) / 2nd gear ratio] or more. (4 seconds)
^ Output speed: [(input speed - 200 r/min) / 2nd gear ratio] or less. (4 seconds)

DESCRIPTIONS OF MONITOR METHODS
In 3rd gear, if a difference between turbine revolution and that value calculated from output revolution equals or exceeds specified value, PCM judges that step-out in 3rd gear has occurred.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored)
^ DTC 27, 28 (P0705): Transmission range switch malfunction
^ DTC 22 (P0715): Input shaft speed sensor malfunction
^ DTC 23 (P0720): Output shaft speed sensor malfunction
^ If DTC 42 (P0732) is set consecutively four times, the transaxle is locked into 3rd gear as a fail-safe measure, and the "N" range light flashes once per second.

OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive at 30 km/h (19 mph) or more for 10 seconds, with 2nd gear fixed (2 range or 2nd gear in sport mode).
^ DTC 36 (P0743): Torque converter clutch solenoid malfunction
^ DTC 31 (P0753): Low-reverse solenoid malfunction
^ DTC 32 (P0758): Underdrive solenoid malfunction
^ DTC 33 (P0763): Second solenoid malfunction
^ DTC 34 (P0768): Overdrive solenoid malfunction
^ DTC 54 (P1751): A/T control relay malfunction
Sensor (The sensor is determined to be normal)
^ Input shaft speed sensor
^ Output shaft speed sensor
^ Transmission range switch
^ Torque converter clutch solenoid
^ Low-reverse solenoid
^ Underdrive solenoid
^ Second solenoid
^ Overdrive solenoid
^ A/T control relay





LOGIC FLOW CHARTS (Monitor Sequence)

DTC SET CONDITIONS
Check Conditions
^ Engine speed: 450 r/min or more.
^ Output speed: 900 r/min or more.
^ Shift stage: 3rd gear.
^ Input speed: more than 0 r/min.
^ Transmission fluid temperature sensor voltage: 4.5 volts or less.
^ Voltage of battery: 10 volts or more.
^ Transmission range switch rationality: only one signal.
^ Time after shift changing finish: 2 seconds or more.

Judgement Criteria
^ Output speed: [(input speed + 200 r/min) / 3rd gear ratio] or more. (4 seconds)
^ Output speed: [(input speed - 200 r/min) / 3rd gear ratio] or less. (4 seconds)

DESCRIPTIONS OF MONITOR METHODS
In 4th gear, if a difference between turbine revolution and that value calculated from output revolution equals or exceeds specified value, PCM judges that step-out in 4th gear has occurred.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored)
^ DTC 27, 28 (P0705): Transmission range switch malfunction
^ DTC 22 (P0715): Input shaft speed sensor malfunction
^ DTC 23 (P0720): Output shaft speed sensor malfunction
^ If DTC 43 (P0733) is set consecutively four times, the transaxle is locked into 3rd gear as a fail-safe measure, and the "N" range light flashes once per second.

OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive at 40 km/h (25 mph) or more for 10 seconds, with 3rd gear fixed (3 range or 3rd gear in sport mode).
^ DTC 36 (P0743): Torque converter clutch solenoid malfunction
^ DTC 31 (P0753): Low-reverse solenoid malfunction
^ DTC 32 (P0758): Underdrive solenoid malfunction
^ DTC 33 (P0763): Second solenoid malfunction
^ DTC 34 (P0768): Overdrive solenoid malfunction
^ DTC 54 (P1751): A/T control relay malfunction
Sensor (The sensor is determined to be normal)
^ Input shaft speed sensor
^ Output shaft speed sensor
^ Transmission range switch
^ Torque converter clutch solenoid
^ Low-reverse solenoid
^ Underdrive solenoid
^ Second solenoid
^ Overdrive solenoid
^ A/T control relay





LOGIC FLOW CHARTS (Monitor Sequence)

DTC SET CONDITIONS
Check Conditions
^ Engine speed: 450 r/min or more.
^ Output speed: 900 r/min or more.
^ Shift stage: 4th gear.
^ Input speed: more than 0 r/min.
^ Transmission fluid temperature sensor voltage: 4.5 volts or less.
^ Voltage of battery: 10 volts or more.
^ Transmission range switch rationality: only one signal.
^ Time after shift changing finish: 2 seconds or more.

Judgement Criteria
^ Output speed: [(input speed + 200 r/min) / 4th gear ratio] or more. (4 seconds)
^ Output speed: [(input speed - 200 r/min) / 4th gear ratio] or less. (4 seconds)

DESCRIPTIONS OF MONITOR METHODS
In reverse gear, if a difference between turbine revolution and that value calculated from output revolution equals or exceeds specified value, PCM judges that step-out in reverse gear has occurred.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored)
^ DTC 27, 28 (P0705): Transmission range switch malfunction
^ DTC 22 (P0715): Input shaft speed sensor malfunction
^ DTC 23 (P0720): Output shaft speed sensor malfunction
^ If DTC 44 (P0734) is set consecutively four times, the transaxle is locked into 3rd gear as a fail-safe measure, and the "N" range light flashes once per second.

OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive at 40 km/h (25 mph) or more for 10 seconds, with 4th gear fixed (D range or 4th gear in sport mode).
^ DTC 36 (P0743): Torque converter clutch solenoid malfunction
^ DTC 31 (P0753): Low-reverse solenoid malfunction
^ DTC 32 (P0758): Underdrive solenoid malfunction
^ DTC 33 (P0763): Second solenoid malfunction
^ DTC 34 (P0768): Overdrive solenoid malfunction
^ DTC 54 (P1751): A/T control relay malfunction
Sensor (The sensor is determined to be normal)
^ Input shaft speed sensor
^ Output shaft speed sensor
^ Transmission range switch
^ Torque converter clutch solenoid
^ Low-reverse solenoid
^ Underdrive solenoid
^ Second solenoid
^ Overdrive solenoid
^ A/T control relay

LOGIC FLOW CHARTS (Monitor Sequence)





DTC SET CONDITIONS
Check Conditions
^ Engine speed: 450 r/min or more.
^ Output speed: 350 r/min or more.
^ Shift stage: reverse gear.
^ Input speed: more than 0 r/min.
^ Transmission fluid temperature sensor voltage: 4.5 volts or less.
^ Voltage of battery: 10 volts or more.
^ Transmission range switch rationality: only one signal.
^ Time after shift changing finish: 2 seconds or more.

Judgement Criteria
^ Output speed: [(input speed + 200 r/min) / reverse gear ratio] or more. (4 seconds)
^ Output speed: [(input speed - 200 r/min) / reverse gear ratio] or less. (4 seconds)

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
^ Malfunction of the input shaft speed sensor
^ Malfunction of the output shaft speed sensor
^ Malfunction of the PCM
^ Malfunction of the underdrive clutch retainer
^ Malfunction of the transfer drive gear or driven gear
^ Malfunction of the low-reverse brake system (DTC 41 or DTC 46)
^ If DTC 46 (P0736) is set consecutively four times, the transaxle is locked into 3rd gear as a fail-safe measure, and the "N" range light flashes once per second.

OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive in "R" range at 15 km/h (9 mph) or more for 10 seconds.
^ Malfunction of the underdrive clutch system (DTC 41, DTC 42, or DTC 43)
^ Malfunction of the second brake system (DTC 42 or DTC 44)
^ Malfunction of the overdrive clutch system (DTC 43 or DTC 44)
^ Malfunction of the reverse clutch system (DTC 46)
^ Electrical noise generated

DIAGNOSIS

Required Special Tool:
^ MB991958: Scan Tool (MUT-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: MUT-III USB Cable
^ MB991911: MUT-III Main Harness B

STEP 1. Using scan tool MB991958, read the A/T diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.





1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to the "ON" position.
3) Check for A/T diagnostic trouble code.
4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC set?
YES : Refer to DTC 22: Input Shaft Speed Sensor System.
YES : Refer to DTC 23: Output Shaft Speed Sensor System.
YES : Refer to DTC 31: Low-Reverse Solenoid Valve System.
YES : Refer to DTC 32: Underdrive Solenoid Valve System.
YES : Refer to DTC 33: Second Solenoid Valve System.
YES : Refer to DTC 34: Overdrive Solenoid Valve System.
NO: Go to Step 2.

STEP 2. Check the hydraulic pressure.
Each hydraulic pressure of the elements, which DTCs indicate, should be within the standard value.
^ DTC 41: Underdrive clutch and low-reverse brake.
^ DTC 42: Underdrive clutch and second brake
^ DTC 43: Underdrive clutch and overdrive clutch
^ DTC 44: Overdrive clutch and second brake
^ DTC 46: Reverse clutch and low-reverse brake
Q: Does the hydraulic pressures meet the standard value range?
YES: Go to Step 5.
NO : Go to Step 4.
NO : Go to Step 3.

STEP 3. Adjust the line pressure.
Adjust the line pressure. Then check the symptom.
Q: Is the symptom eliminated?
YES: The procedure is complete.
NO: Go to Step 4.

STEP 4. Disassemble and clean the valve body.





Check the O-ring installation bolts for looseness and the valve body for damage. Repair or replace the faulty parts.
Replace the valve body assembly if the damages are thought to be irreparable. Then check the symptom.
Q: Is the symptom eliminated?
YES: The procedure is complete.
NO: Go to Step 6.

STEP 5. Replace the PCM.
1) Replace the PCM.
2) Test drive the vehicle.
3) Check for A/T diagnostic trouble code.
Q: Were any A/T DTCs set?
YES: Go to Step 6.
NO: The procedure is complete.

STEP 6. Overhaul the A/T.





1) Replace the following parts.
^ If DTC 41, DTC 42, or DTC 43 are set individually or in a group, replace the underdrive clutch.
^ If DTC 43 or DTC 44 are set individually or in a group, replace the overdrive clutch.
^ If DTC 46 is set, replace the reverse clutch.
^ If DTC 41 or DTC 46 are set individually or in a group, replace the low-reverse brake.
^ If DTC 42 or DTC 44 are set individually or in a group, replace the second brake.
^ If DTC 41 is set, replace the one-way clutch.
2) Test drive the vehicle.
3) Check for A/T diagnostic trouble code.
Q: Are any A/T DTCs set again?
YES: An A/T DTC may have set due to external Radio Frequency Interference (RFI) possibly caused by cellular phone activity, or aftermarket components installed on the vehicle.
NO: The procedure is complete.