NO.8 DOES NOT SHIFT TO 4GR [GF4AX-EL]


8	Does not shift to 4GR
DESCRIPTION	• Vehicle does not upshift from 3GR to 4GR even though vehicle speed is increased. • Vehicle does not shift to 4GR even though accelerator pedal is released in D range at 60 km/h {37 mph}.
POSSIBLE CAUSE	• Basically, TCC does not operate when fail-safe is operating. Verify the DTCs first. If the TCC operates when driving at high speeds only, the malfunction (improper adjustment) is in the O/D OFF switch circuit or TR switch circuit. Caution • If the TCC is stuck, inspect it. In addition, inspect the oil cooler for foreign particles which may have mixed in with the ATF. 1. TCC piston slippage, burnt • Line pressure low • TP sensor malfunction • ECT sensor malfunction • VSS malfunction • Input/turbine speed sensor malfunction • Sensor GND malfunction 2. TFT sensor malfunction • Short or open circuit in wiring harness • Poor connection of connector • Sensor malfunction 3. TR switch malfunction • Short or open circuit in wiring harness • Poor connection of connector • Sensor malfunction • Selector lever adjustment incorrect • TR switch adjustment incorrect 4. TCC solenoid valve malfunction • Short or open circuit in wiring harness • Poor connection of connector • Solenoid valve stuck 5. O/D OFF switch malfunction 6. Torque converter malfunction 7. Control valve body malfunction Note • Before following the troubleshooting steps, make sure that the Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted.


STEP	INSPECTION		ACTION
1	Turn the ignition switch to the ON position. Does the O/D OFF indicator light indication correspond to the O/D OFF switch operation?	Yes	Go to the next step.
1		No	Go to No.26 "O/D OFF INDICATOR LIGHT DOES NOT ILLUMINATE WHEN O/D OFF SWITCH IS TURNED TO ON", or No.27 "O/D OFF INDICATOR LIGHT ILLUMINATES WHEN O/D OFF SWITCH IS NOT TURNED TO ON".
2	Drive the vehicle in D range and inspect following: 1-2 shift up and down 2-3 shift up and down Are all shift-up and shift-down possible?	Yes	Go to the next step.
2		No	No shift at all: • Go to No.7 "NO SHIFTING". Abnormal shift: • Go to No.9 "ABNORMAL SHIFTING".
3	Connect the WDS or equivalent to DLC-2. Access TFT and TFTV PIDs. Drive the vehicle while monitoring PIDs. (See PCM INSPECTION [L3 R.H.D.].) Are the PIDs within the specification?	Yes	Go to the next step.
3		No	Inspect the TFT sensor and related wiring harness: vibration, intermittent open/short circuit.
4	Access TRD, TP, TSS and VSS PIDs. Drive the vehicle in D range while monitoring PIDs (O/D OFF switch off). (See PCM INSPECTION [L3 R.H.D.].) Are the PIDs within the specification?	Yes	Go to the next step.
4		No	TRD PID: • Inspect the TR switch and related wiring harness: for intermittent open/short circuit during vibration. TP PID: • Inspect that the output signal from the TP sensor changes smoothly. TSS PID: • Inspect the input/turbine speed sensor and related wiring harness: for intermittent open/short circuit during vibration. VSS PID: • Inspect for intermittent open circuit at the VSS and related wiring harness.
5	Stop the engine and turn the ignition switch to the ON position. Connect the WDS or equivalent to DLC-2. Simulate SSA/SS1, SSB/SS2 and SSC/SS3 PIDs for ON. Is operating sound of the shift solenoids heard?	Yes	Go to the next step.
5		No	Inspect connection of the shift solenoid A, B, or C terminal on the ATX for bent terminals damage, corrosion or looseness. Inspect for stuck shift solenoid? (See Operating Inspection (On-vehicle Inspection).) If the shift solenoids are normal, inspect for open or short circuit between the PCM terminals 92, 66 or 40 and the coupler component terminals A, B, or C.
6	Remove the torque converter. Inspect the torque converter. (See ATX Workshop Manual (GF4AX-EL)) Is the torque converter normal?	Yes	Replace the control valve body and repair or replace any malfunctioning parts. (See ATX Workshop Manual (GF4AX-EL)) If any problem remains, replace the transaxle and repair or replace any malfunctioning parts. (See AUTOMATIC TRANSAXLE AND TRANSFER REMOVAL/INSTALLATION [GF4AX-EL].)
6		No	Replace the torque converter.
7	• Verify the test results. - If normal, return to the diagnostic index to service any additional symptoms. - If the malfunction remains, inspect the related Service Information and perform repair or diagnosis. • If the vehicle is repaired, troubleshooting is completed. • If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.