Part 1

DTC B1065: Mode Selection Damper Control Motor and Potentiometer (Activating System Failure)

Mode Selection Damper Control Motor Circuit:

FUNCTION
Drive the mode selection damper control motor and control the outlet selection.

DETECTION LOGIC
This code is set when the mode selection damper cannot be rotated to the preset opening angle.

PROBABLE CAUSES
- Malfunction of connector.
- Malfunction of the harness (mode selection damper control motor and potentiometer circuit is open, shorted to ground, or the resistance has increased)
- Malfunction of the mode selection damper control motor and potentiometer.
- Malfunction of the A/C pressure sensor.
- Malfunction of the A/C-ECU.

DIAGNOSIS

Required Special Tool:
- 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, read the diagnostic trouble code.

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.




Check if an A/C-ECU 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 diagnostic trouble code B1045 set?

YES: Refer to DTC B1045.

NO: Go to Step 2.

STEP 2. Using scan tool MB991958, check actuator test.

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 67: air outlet c/o damper (Bi_Level position)
- Item 68: air mix damper motor (DEF position)
- Item 69: air mix damper motor (DEF/FOOT position)
- Item 70: air mix damper motor (FACE position)
- Item 71: air mix damper motor (FOOT position)
- Check that the mode selection damper control motor operates.

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

Q: Does the motor operate normally?

YES: Go to Step 4.

NO: Go to Step 3.

STEP 3. Recheck for diagnostic trouble code.

Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "OFF" position.
3. Turn the ignition switch to "ON" position.
4. Drive the vehicle and check if the diagnostic trouble code is set.

Q: Is the check result satisfactory?

YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions.

NO: Replace the A/C-ECU.







STEP 4. Check A/C-ECU connector C-15 and mode selection damper control motor and potentiometer connector C-104 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-104 in good condition?

YES: Go to Step 5.

NO: Repair or replace the connector. Refer to Harness Connector Inspection.