DTC P0734[FN4A-EL]


id0502a1802200

DTC P0734

Gear 4 incorrect (incorrect gear ratio detected)

DETECTION CONDITION
•  The PCM monitors revolution ratio of the forward clutch drum revolution to the differential gear case revolution when the following monitoring conditions are met. If the revolution ratio is 0.57 (ZY)/0.6 (Z6, LF) or less or 1.277 (ZY)/1.249 (Z6, LF) or more, the PCM determines that there is a malfunction.
Monitoring condition:
―  Engine running
―  ATF temperature 20 °C {68 °F} or more
―  Driving in 4 GR in D or M range
―  Turbine speed within 225—4,987 rpm
―  Vehicle speed 27 km/h {17 mph} or more (ZY)
―  Vehicle speed 28 km/h {18 mph} or more (Z6)
―  Vehicle speed 31 km/h {19 mph} or more (LF)
―  Closed throttle position
―  Differential gear case (output) revolution speed 35 rpm or more
―  None of the following DTCs are present: P0706, P0707, P0708, P0712, P0713, P0715, P0720, P0751, P0752, P0753, P0756, P0757, P0758, P0761, P0762, P0763, P0766, P0767, P0768, P0771, P0772, P0773
•  The PCM monitors revolution ratio of the forward clutch drum revolution to the differential gear case revolution when the following monitoring conditions are met. If the revolution ratio is within 0.91—1.09, the PCM determines that there is a malfunction.
Monitoring condition:
―  Engine running
―  ATF temperature 20 °C {68 °F} or more
―  Driving in 4 GR in D or M range
―  Torque converter clutch (TCC) not operating
―  Turbine speed within 225—4,987 rpm
―  Vehicle speed 28 km/h {18 mph} or more (ZY)
―  Vehicle speed 29 km/h {18 mph} or more (Z6)
―  Vehicle speed 46 km/h {29 mph} or more (LF)
―  Differential gear case (output) revolution speed 35 rpm or more
―  None of the following DTCs are present: P0706, P0707, P0708, P0712, P0713, P0715, P0720, P0751, P0752, P0753, P0756, P0757, P0758, P0761, P0762, P0763, P0766, P0767, P0768, P0771, P0772, P0773
Diagnostic support note:
•  This is a continuous monitor (CCM).
•  The MIL does not illuminate.
•  The AT warning light illuminates if the PCM detects the above malfunction condition during the first drive cycle.
•  FREEZE FRAME DATA is not available.
•  A PENDING CODE is not available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  ATF level low
•  Deteriorated ATF
•  Shift solenoids A, B or C stuck
•  Pressure control solenoid stuck
•  Line pressure low
•  2-4 brake band slipping
•  3-4 clutch slipping
•  Forward clutch slipping
•  Control valve stuck (Bypass or 3-4 shift valve)
•  Oil pump malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
2
INSPECT ATF CONDITION
•  Inspect the ATF condition.
•  Is it normal?
Yes
Go to the next step.
No
Replace the transaxle, then go to Step 8.
3
INSPECT ATF LEVEL
•  Start the engine.
•  Warm up the ATX.
•  Is the ATF level within the specification?
Yes
Go to the next step.
No
Add ATF to the specified level, then go to Step 8.
4
INSPECT SHIFT SOLENOID A AND D FOR CLICK SOUND
•  Perform operation inspection.
•  Verify the click sound of shift solenoids A and D when applying B+ to each transaxle terminal.
Note
•  The click from solenoid D is barely audible. Remove solenoids to correctly inspect if necessary.
•  Was a click heard from solenoids?
Yes
Go to the next step.
No
Replace the solenoid where you could not hear click sound, then go to Step 8.
5
INSPECT LINE PRESSURE
•  Start the engine.
•  Measure the line pressures.
•  Are the line pressures within the specifications?
Yes
Go to the next step.
No
All ranges: Replace the oil pump, then go to Step 8.
Any ranges: Replace the control valve body, then go to Step 8.
6
INSPECT STALL SPEED
•  Measure the stall speed in D range.
•  Is the stall speed within the specification?
Yes
Go to the next step.
No
Replace the automatic transaxle, then go to Step 8.
7
INSPECT FREQUENCY OF INPUT/TURBINE SPEED SENSOR WHEN DRIVING VEHICLE
•  Turn the ignition switch to the LOCK position.
•  Connect the M-MDS.
•  Start the engine.
•  Measure the frequency of input/turbine speed sensor while driving vehicle under the following conditions:
―  Vehicle speed (VSS PID): 80 km/h {49 mph}
―  Drive in the D range, 4GR
―  Throttle opening angle (THOP PID): approx. 25%
•  Was the frequency of the input/turbine speed sensor at approx. 1,200 Hz?
Yes
Go to the next step.
No
Replace the control valve body, then go to the next step.
8
VERIFY REPAIR OF DTC P0734
•  Make sure to reconnect all the disconnected connectors.
•  Clear the DTC using the M-MDS.
•  Start the engine.
•  Warm up the transaxle.
•  Drive the vehicle under the following conditions for more than 5 s:
―  ATF temperature: 20 °C {68 °F} or more
―  Drive in the D range, 4GR
―  Throttle opening angle (THOP PID): 0%
―  Vehicle speed (VSS PID): 28 km/h {18 mph} or more (ZY)
―  Vehicle speed (VSS PID): 29 km/h {18 mph} or more (Z6)
―  Vehicle speed (VSS PID): 46 km/h {29 mph} or more (LF)
•  Are any DTCs present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
9
VERIFY AFTER REPAIR PROCEDURE
•  Perform the "After Repair Procedure".
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.