Dtc B1488/88 Rear Air Mix Damper Control Servo Motor Circuit On Front Passenger Side

Vehicle Interior. Land Cruiser. Urj200, 202 Grj200 Vdj200
Heating Air Conditioning. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (REAR AIR MIX DAMPER SERVO MOTOR)

CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER)

CHECK REAR AIR MIX DAMPER SERVO MOTOR

CHECK NO. 2 AIR CONDITIONING HARNESS ASSEMBLY

DTC B1488/88 Rear Air Mix Damper Control Servo Motor Circuit on Front Passenger Side


DESCRIPTION

The rear air mix damper servo motor RH*1 or LH*2 sends pulse signals to indicate the damper position to the air conditioning amplifier assembly. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the rear air mix damper to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the blown air.
HINT:
Confirm that no mechanical problem is present because this trouble code can be output when either a damper link or damper is mechanically locked.

DTC Code
DTC Detection Condition
Trouble Area
B1488/88
The rear air mix damper position does not change even if the air conditioning amplifier assembly operates the air mix damper servo motor.
  1. Rear air mix damper servo motor RH*1
  2. Rear air mix damper servo motor LH*2
  3. No. 2 air conditioning harness assembly
  4. Harness or connector
  5. Air conditioning amplifier assembly
HINT:
*1: for LHD
*2: for RHD

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc B1488/88 Rear Air Mix Damper Control Servo Motor Circuit On Front Passenger Side


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (REAR AIR MIX DAMPER SERVO MOTOR)

  1. Use the Data List to check if the servo motor is functioning properly.

    Air Conditioner
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    A/M Servo Targ Pulse (Rear P)
    		Rear air mix damper servo motor (for front passenger side) target pulse /
    Min.: 8, Max.: 53 (for LHD)
    Min.: 9, Max.: 54 (for RHD)
    		for LHD
    1. MAX COOL: 53 (pulse)
    2. MAX HOT: 8 (pulse)
    for RHD
    1. MAX COOL: 9 (pulse)
    2. MAX HOT: 54 (pulse)
    		-
    OK:
    The display is as specified in the normal condition.

    Result
    Result
    		Proceed to
    OK (Checking from the DTC)
    		A
    OK (Checking from the PROBLEM SYMPTOMS TABLE)
    		B
    NG
    		C


B
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)

C
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)
A


2.CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER)
Land Cruiser. Urj200, 202 Grj200 Vdj200.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc B1488/88 Rear Air Mix Damper Control Servo Motor Circuit On Front Passenger Side

  1. Disconnect the K19 No. 2 air conditioning harness connector.

  1. Disconnect the E36 amplifier connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    K19-2 (RBUG) - E36-12 (RBUG)
    		Always
    		Below 1 Ω
    K19-3 (RBUS) - E36-13 (RBUS)
    K19-4 (RBBU) - E36-14 (RBBU)
    E36-12 (RBUG) - Body ground
    		Always
    		10 kΩ or higher
    E36-13 (RBUS) - Body ground
    E36-14 (RBBU) - Body ground


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK REAR AIR MIX DAMPER SERVO MOTOR

  1. Replace the rear air mix damper servo motor (Click here).

    HINT:
    Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one.

  1. Clear the DTCs (Click here).

  1. Check for DTCs (Click here).

    Result
    Result
    		Proceed to
    DTC B1488/88 is not output
    		A
    DTC B1488/88 is output
    		B


B
Go to step 4
A

END (REAR AIR MIX DAMPER SERVO MOTOR IS DEFECTIVE)

4.CHECK NO. 2 AIR CONDITIONING HARNESS ASSEMBLY

  1. Replace the No. 2 air conditioning harness assembly (Click here).

  1. Clear the DTCs (Click here).

  1. Check for DTCs (Click here).

    Result
    Result
    		Proceed to
    DTC B1488/88 is not output
    		A
    DTC B1488/88 is output
    		B


B
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)
A

END (NO. 2 AIR CONDITIONING HARNESS ASSEMBLY IS DEFECTIVE)