NO.9 ABNORMAL SHIFTING[GF4AX-EL]

id0503a3801400

9

Abnormal shifting

DESCRIPTION

•  Shift incorrectly (incorrect shift pattern).

POSSIBLE CAUSE

•  There is a malfunction in the signal circuit which controls shifting (TP sensor, input/turbine speed sensor, VSS); the control valve is stuck, or the clutch circuit is stuck.

1.  Clutch slippage, burnt

•  Line pressure low

•  APP sensor malfunction

•  VSS malfunction

•  Input/turbine speed sensor malfunction

•  Sensor GND malfunction

•  Shift solenoid A, B, or C malfunction

•  TCC solenoid valve malfunction

•  Body GND malfunction

•  Accelerator cable mis-adjustment

•  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.

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Inspect for continuity between the PCM terminals 1AZ, 1BB, 1BD or 1BH and the transaxle case. Is there continuity?	Yes	Go to the next step.
1		No	Repair or replace GND circuit.
2	Connect the M-MDS to DLC-2. Access TRD, TRL, TRS, APP1, APP2, TSS and VSS PIDs. Drive the vehicle in D, 2, and 1 ranges while monitoring PIDs (O/D OFF switch off). (See PCM INSPECTION[L3].) Are the PIDs within the specification?	Yes	Go to the next step.
2		No	TRD, TRL or TRS PID: • Inspect the TR switch and related wiring harness: for intermittent open/short circuit during vibration. APP1, APP2 PID: • Inspect if output signal from the APP sensor for smooth changes. 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 of the VSS and related wiring harness.
3	Stop the engine and turn the ignition switch to the ON position. Connect the M-MDS to DLC-2. Simulate SSA/SS1, SSB/SS2 and SSC/SS3 PIDs for ON. Is operating sound of the shift solenoids heard?	Yes	Inspect the PCM connector terminal for bent terminal, damage, corrosion or poor contact.
3		No	Inspect connection of the shift solenoid A, B, or C terminal on the ATX for bend, damage, corrosion or looseness. Inspect for stuck shift solenoid? (See SOLENOID VALVE INSPECTION[GF4AX-EL].) If the shift solenoids are normal, inspect for open or short circuit between the PCM terminals 1E, 1F or 1G and the coupler component terminals A, B, or C.
4	• 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.