NO.14 ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING [FN4A-EL]

id050301801900

14
Engine flares up or slips when upshifting or downshifting
DESCRIPTION
•  When the accelerator pedal is depressed, engine speed increases normally but vehicle speed increases slowly.
•  When the accelerator pedal is depressed while driving, engine speed increases but vehicle speed does not increase.
POSSIBLE CAUSE
•  There is clutch slip because clutch is stuck or line pressure is low.
1.  Clutch stuck, slippage (forward clutch, 3–4 clutch, 2–4 brake band, one-way clutch)
•  Line pressure low
•  Shift solenoid A malfunction
•  Shift solenoid B malfunction
•  Shift solenoid C malfunction
•  Shift solenoid D malfunction
•  Shift solenoid E malfunction
•  Pressure control solenoid malfunction
•  APP sensor malfunction
•  Control valve body malfunction
•  Body GND malfunction
2.  Signal malfunction
•  APP sensor malfunction
•  Input/turbine speed sensor malfunction
•  VSS malfunction
•  Sensor GND malfunction
3.  Poor operation of mechanical pressure
•  Selector cable adjustment incorrect
•  TR switch position disparity
Note
•  Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted. (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [FN4A-EL].) (See BASIC INSPECTION [FN4A-EL].)

Diagnostic procedure

STEP

INSPECTION

ACTION
1
Is the shift point normal?
Yes
Go to the next step.
No
Go to the symptom troubleshooting “NO.9 ABNORMAL SHIFTING”.
(See NO.9 ABNORMAL SHIFTING [FN4A-EL].)
2
Inspect the APP PID value using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.5, MZR 1.6].)
Is the PID value normal?
(See PCM INSPECTION [MZR 1.5, MZR 1.6].)
Yes
Go to the next step.
No
Repair or replace any malfunctioning parts.
3
Disconnect the PCM connector.
Measure the resistance between ground terminal at the PCM connector and body ground.
Is the resistance less than 5.0 ohms?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit.
4
Inspect the LPS PID value using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.5, MZR 1.6].)
Is the PID value normal?
(See PCM INSPECTION [MZR 1.5, MZR 1.6].)
Yes
Overhaul the control valve body and repair or replace any malfunctioning parts.
If any problem remains:
•  Overhaul the transaxle and repair or replace any malfunctioning parts.
No
Repair or replace any malfunctioning parts.
5
•  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. (See PCM REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)