NO.9 ABNORMAL SHIFTING [FN4A-EL]


id0503a1801400

9

Abnormal shifting

DESCRIPTION

• Shifts incorrectly (incorrect shift pattern).

POSSIBLE CAUSE

• There is a malfunction in the signal circuit which controls shifting (TP sensor, input/turbine speed sensor, vehicle speed sensor), the control valve is stuck, the accumulator (forward or servo apply) is stuck, or the clutch circuit is stuck.
1. Clutch slipped, burned
• Line pressure low
• Control valve body malfunction
• Shift solenoid D malfunction
• Shift solenoid E malfunction
• Shift solenoid A malfunction
• Shift solenoid B malfunction
• Shift solenoid C malfunction
• Body GND malfunction
• Accelerator cable misadjustment
2. Signal malfunction
• Vehicle speed sensor malfunction
• Sensor GND malfunction
• TP sensor malfunction or mis-adjustment
• Input/turbine speed sensor malfunction
3. TR switch malfunction
• Selector lever adjustment incorrect
• TR sensor adjustment incorrect
Note
• Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted.

Diagnostic procedure

STEP

INSPECTION

ACTION

1
• Disconnect PCM.
• Is resistance between ground terminal at PCM connector and body ground less than 5.0 ohms?
Yes
Go to next step.
No
Repair open ground circuit. Reconnect PCM.
2
• Check the value at the following PIDs using the WDS or equivalent.
- TP
- TSS
- VSS
• Is PID value normal?
Yes
Overhaul control valve body and repair or replace any defective parts.
(See ATX workshop manual (FN4A-EL) [1623-10-98E].)
If problem remains, overhaul transaxle and repair or replace any defective parts.
(See ATX workshop manual (FN4A-EL) [1623-10-98E].)
No
Repair or replace any defective parts.
3
• Verify test results.
- If normal, return to diagnostic index to service any additional symptoms.
- If malfunction remains, inspect related Service Information and perform repair or diagnosis.
• If vehicle repaired, troubleshooting completed.
• If vehicle not repaired or additional diagnostic information not available, replace PCM.