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2008 - MX-5 - Transmission/Transaxle

NO.8 DOES NOT SHIFT TO 6GR [SJ6A-EL]



8

Does not shift to 6GR

DESCRIPTION

  • Vehicle does not upshift from 5GR to 6GR even though vehicle speed is increased.

  • Vehicle does not shift to 6GR even though accelerator pedal is released in D range at 80 km/h {50 mph}.

POSSIBLE CAUSE

  • Basically, TCC does not operate when the fail-safe is operating. Verify the DTC at first. If the TCC operates when driving at high speeds only, the malfunction (improper adjustment) is in the M range 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.

    • C2 clutch, C3 clutch, B2 brake slippage, burnt

      • 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

      • Short or open circuit in wiring harness

      • Poor connection of connector

      • Sensor malfunction

    • TR switch malfunction

      • Selector lever adjustment incorrect

      • TR switch adjustment incorrect

    • Shift solenoid A, shift solenoid B, shift solenoid C, shift solenoid D, shift solenoid G, line pressure control solenoid malfunction

      • Short or open circuit in wiring harness

      • Poor connection of connector

      • Solenoid valve stuck

    • M range switch malfunction

      • Selector lever adjustment incorrect

      • Short or open circuit in wiring harness

    • Torque converter malfunction

    • Control valve body 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

  • With the ignition switch at the ON position.

  • Does the gear position indicator light indication correspond to selector lever position?

Yes

Go to the next step.

No

Go to No.27 “GEAR POSITION INDICATOR LIGHT DOES NOT ILLUMINATE IN M RANGE”, or No.28 “GEAR POSITION INDICATOR LIGHT ILLUMINATES IN D RANGE OR P, N, R POSITIONS”.

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

  • Drive the vehicle in D range and inspect following:

    • 1–2 shift up and down

    • 2–3 shift up and down

    • 3–4 shift up and down

    • 4–5 shift up and down

    • 5–6 shift up and down

  • Are all shift-up and shift-down possible?

Yes

Go to the next step.

No

No shift at all:

  • Go to No.7 “NO SHIFTING”.

Abnormal shift:

  • Go to No.9 “ABNORMAL SHIFTING”.

5

  • Stop the engine.

  • Inspect following solenoid.

    (See SOLENOID VALVE INSPECTION [SJ6A-EL].)

    • Shift solenoid A

    • Shift solenoid B

    • Shift solenoid C

    • Shift solenoid D

    • Shift solenoid F

    • Line pressure control solenoid

  • Are they normal?

Yes

Go to the next step.

No

Inspect for shift solenoid stuck.

(See SOLENOID VALVE INSPECTION [SJ6A-EL].)

6

Yes

Inspect the ATF condition.

No

Replace the torque converter.

7

  • 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.




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