DTC P0666:00

ECU internal temperature sensor circuit malfunction

DETECTION CONDITION

• Under the following condition, there is malfunction in circuit of ECU internal temperature sensor:

• Battery voltage is 8 V or more.

Diagnostic support note

• The check engine light illuminates if the TCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the TCM.

• The automatic transaxle warning light illuminates if the TCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the TCM.

• PENDING CODE is available.

• FREEZE FRAME DATA is available.

• DTC is stored in the TCM memory.

FAIL-SAFE FUNCTION

• Inhibits learning control.

• Inhibits neutral idle control.

POSSIBLE CAUSE

• Control valve body malfunction

• ECU internal temperature sensor (built-into TCM) malfunction

SYSTEM WIRING DIAGRAM

Not applicable

STEP

INSPECTION

ACTION

1

• Has the freeze frame data/snapshot data been recorded on the repair order?

Yes

Go to the next step.

No

Record the freeze frame data/snapshot data on the repair order, then go to the next step.

2

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, replace the control valve body.

  (See CONTROL VALVE BODY REMOVAL/INSTALLATION [FW6A-EL].)

Go to the next step.

No

Replace the control valve body, then go to the next step.

(See CONTROL VALVE BODY REMOVAL/INSTALLATION [FW6A-EL].)

3

• Clear the DTC using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [FW6A-EL].)

• Perform the following procedure to ensure that the DTC has been resolved:

• Start the engine.

• Perform the DTC inspection using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [FW6A-EL].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [FW6A-EL].)

No

DTC troubleshooting completed.