B1065

DTC B1065: Mode Selection Damper Control Motor And Potentiometer

Mode Selection Damper Control Motor Circuit:

DTC SET CONDITION
- If the air mixing damper control motor does not work normally, DTC B1065 will be set.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble
- The A/C-ECU, the mode selection damper control motor and potentiometer, or connector(s) or wiring between them may be defective.

Past trouble
- If DTC B1065 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) between the A/C-ECU and the mode selection damper control motor and potentiometer. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU. If in doubt, do not replace the ECU.

TROUBLESHOOTING HINT
- Malfunction of connector.
- Malfunction of the harness.
- Malfunction of the mode selection damper control motor and potentiometer.
- Malfunction of the A/C-ECU.

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

Use scan tool MB991958 to diagnose the CAN bus lines.







1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Diagnose the CAN bus line.

Q: Is the check result satisfactory?

YES : Go to Step 2.

NO : Repair the CAN bus lines. Then go to Step 7.

STEP 2. Recheck for diagnostic trouble code.

Recheck if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.

Q: Is the check result satisfactory?

YES : It can be assumed that this malfunction is intermittent.

NO : Go to Step 3.

STEP 3. Using scan tool MB991958, check actuator test.







CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Start the engine.
3. Use scan tool MB991958 to run the actuator test.
Item 13: air mix damper motor (FACE position)
Item 14: air mix damper motor (FOOT/FACE position)
Item 15: air mix damper motor (FOOT position)
Item 16: air mix damper motor (DEF/FOOT position)
Item 17: air mix damper motor (DEF position)
- Check that the mode selection damper control motor operates.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the sensor within the specified range?

YES : Replace the A/C-ECU. Then go to Step 7.

NO : Go to Step 4.

STEP 4. Check A/C-ECU connector C-15 and mode selection damper control motor and potentiometer connector C-102 for loose, corroded or damaged terminals, or terminals pushed back in the connector.










Q: Are A/C-ECU connector C-15 and mode selection damper control motor and potentiometer connector C-102 in good condition?

YES : Go to Step 5.

NO : Repair or replace the connector. Then go to Step 7.

STEP 5. Check the wiring harness between A/C-ECU connector C-15 (terminals 11 and 4) and mode selection damper control motor and potentiometer connector C-102 (terminals 1 and 2).










- Check the A/C-ECU signal line for open and short circuit.

Q: Are the wiring harnesses between A/C-ECU connector C-15 (terminals 11 and 4) and mode selection damper control motor and potentiometer connector C-102 (terminals 1 and 2) in good condition?

YES : Go to Step 6.

NO : Repair the wiring harness. Then go to Step 7.

STEP 6. Check the mode selection damper control motor.

CAUTION: Do not apply battery voltage when the damper is in the FACE or DEF position.







Check the mode selection damper control motor by the following procedures.







Q: Is the mode selection damper control motor in good condition?

YES : Go to Step 7.

NO : Replace the mode selection damper control motor and potentiometer. Then go to Step 7.

STEP 7. Recheck for diagnostic trouble code.







Check again if the DTC is set.

1. Connect scan tool MB991958 to the data link connector
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the check result satisfactory?

YES : Repair the A/C-ECU. The procedure is complete.

NO : Return to Step 1.