Drivetrain

Torque Converter Clutch (TCC) Non Operation [Fw6 A EL]

~2min read

TROUBLESHOOTING ITEM

Torque converter clutch (TCC) non-operation

DESCRIPTION
  • TCC does not operate when vehicle reaches TCC operation range.

POSSIBLE CAUSE
  • Signal malfunction

    • APP sensor malfunction

    • Brake switch malfunction

    • CKP sensor malfunction

    • ECT sensor No.1 malfunction

  • Poor GND

  • Torque converter malfunction


CAUTION:
  • Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.

Related PIDs

Monitor item (Definition)

Unit/Condition

Condition/Specification (Reference)

APP

%

  • Accelerator pedal released: approx. 0 %
  • Accelerator pedal depressed: approx. 100 %

BOO

OFF/ON

  • Brake pedal released: Off

  • Brake pedal depressed: On

ECT

°C, °F

  • Displays the ECT

V

  • ECT is 20 °C {68 °F}: approx. 3.10 V
  • ECT is 40 °C {104 °F}: approx. 2.16 V
  • ECT is 60 °C {140 °F}: approx. 1.40 V
  • ECT is 80 °C {176 °F}: approx. 0.87 V
  • ECT is 100 °C {212 °F}: approx. 0.54 V

RPM

RPM

  • Displays the engine speed


Diagnostic procedure

STEP

INSPECTION

ACTION

1

INSPECT SIGNAL PARTS FOR MALFUNCTION
  • Inspect the value at the following PCM PIDs using the M-MDS.

    (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0].)

    • APP (APP sensor)

    • BOO (Brake switch)

    • ECT (ECT sensor No.1)

    • RPM (CKP sensor)

  • Is there any malfunction?

Yes

Repair or replace any malfunctioning parts according to the inspection result.

No

Go to the next step.

2

VERIFY IF MALFUNCTION CAUSE IS TCM GND OR TORQUE CONVERTER
  • Switch the ignition to off.

  • Disconnect the TCM connector.

  • Visually inspect for pin deformity, open circuit, or wiring harness non-insulation between TCM terminal 1B and body GND.

  • Is there any malfunction?

Yes

Repair or replace any malfunctioning parts according to the inspection result.

No

Replace the torque converter.

(See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [FW6A-EL].)

Test yourself

A quick Mazda 3 quiz: every answer comes with an explanation and a link to the manual page.