Home

< Previous   Next >

2008 - MX-5 - Transmission/Transaxle

NO.9 ABNORMAL SHIFTING [SJ6A-EL]



9

Abnormal shifting

DESCRIPTION

  • Shift incorrectly (incorrect shift pattern).

POSSIBLE CAUSE

  • There is a malfunction in the signal circuit which controls shifting (Throttle position signal, turbine sensor, VSS), the control valve is stuck, or the clutch circuit is stuck.

    • Clutch slippage, burnt (C1 clutch, C2 clutch, C3 clutch, B1 brake, B2 brake, B3 brake)

      • Line pressure low

      • Incorrect throttle position signal

      • Incorrect accelerator pedal position signal

      • Incorrect engine speed signal

      • Incorrect engine coolant temperature signal

      • Incorrect engine torque signal

      • VSS malfunction

      • Turbine sensor malfunction

      • Sensor GND malfunction

      • TFT sensor malfunction

      • Line pressure control solenoid malfunction

      • Body GND malfunction

      • Control valve body malfunction

      • TCM malfunction

NOTE:

  • Before following the troubleshooting steps, make sure that the Automatic Transmission On-Board Diagnostic and Automatic Transmission Basic Inspection are conducted. (See BASIC INSPECTION [SJ6A-EL].)


Diagnostic procedure

STEP

INSPECTION

ACTION

1

  • Inspect for continuity between the TCM terminal 1P, 1X and battery negative terminal.

  • Is there continuity?

Yes

Go to the next step.

No

Repair or replace ground circuit.

2

  • Access the following PCM PIDs using the M-MDS.

    • RPM

    • APP

    • TP

    • ECT

    • ENG_TRQ

  • Are PIDs value normal?

Yes

Go to the next step.

No

Inspect and repair suspected PID related part.

3

Yes

Go to the next step.

No

Replace the TFT sensor.

4

Yes

Inspect the TCM terminal for bend, damage, corrosion or poor contact.

No

Inspect the coupler component.

If normal, replace the control valve body.

(See CONTROL VALVE BODY REMOVAL [SJ6A-EL].)

(See CONTROL VALVE BODY INSTALLATION [SJ6A-EL].)

5

  • Verify test results.

    • If normal, return to the diagnostic index to service any additional symptoms.

    • If malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.

      • If the vehicle is repaired, troubleshooting completed.

      • If the vehicle is not repaired or additional diagnostic information is not available, replace the TCM.




< Previous   Next >
Back to Top
© 2009 Mazda North American Operations, U.S.A.