B1447
HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1447/47: Rear Air Mix Damper Control Servo Motor Circuit
B1447/47 - Rear Air Mix Damper Control Servo Motor Circuit
DESCRIPTION
The rear No. 1 cooling unit damper servo sub-assembly (rear air mix damper servo) sends pulse signals to indicate the damper position to the air conditioning amplifier. The air conditioning amplifier activates the motor (normal or reverse) based on these signals to move the rear air mix damper to any position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted and the temperature of the air blowing toward the rear is controlled.
The air conditioning amplifier communicates with the servo through the No. 2 air conditioning harness assembly.
HINT
Confirm that there are no mechanical problems because this DTC may be stored when either a damper link or damper is mechanically locked.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. READ VALUE USING TECHSTREAM (REAR AIR MIX DAMPER SERVO)
(a) Use the Data List to check if the rear No. 1 cooling unit damper servo sub-assembly (rear air mix damper servo) is functioning properly Scan Tool Testing and Procedures.
Air Conditioner
OK:
The display is as specified in the normal condition column.
Result
C -- PERFORM ACTIVE TEST USING TECHSTREAM (REAR AIR MIX DAMPER SERVO)
B -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal
A -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures
2. PERFORM ACTIVE TEST USING TECHSTREAM (REAR AIR MIX DAMPER SERVO)
(a) Select the Active Test, use the Techstream to generate a control command, and then check that the rear No. 1 cooling unit damper servo sub-assembly (rear air mix damper servo) operates Scan Tool Testing and Procedures.
Air Conditioner
OK:
Rear No. 1 cooling unit damper servo sub-assembly (rear air mix damper servo) operates normally.
NG -- CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER)
OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal
3. CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER)
(a) Disconnect the Q13 harness connector.
(b) Disconnect the G12 amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. REPLACE REAR NO. 1 COOLING UNIT DAMPER SERVO SUB-ASSEMBLY (REAR AIR MIX DAMPER SERVO)
(a) Replace the rear No. 1 cooling unit damper servo sub-assembly (rear air mix damper servo) Disassembly.
HINT
Since the rear No. 1 cooling unit damper servo sub-assembly (rear air mix damper servo) cannot be inspected while it is removed from the vehicle, replace the rear No. 1 cooling unit damper servo sub-assembly (rear air mix damper servo) with a new or normally functioning one.
NEXT -- Continue to next step.
5. CHECK FOR DTC
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B1447 is not output.
NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
OK -- END (REAR NO. 1 COOLING UNIT DAMPER SERVO SUB-ASSEMBLY [REAR AIR MIX DAMPER SERVO] IS FAULTY
6. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
(a) Temporarily replace the air conditioning amplifier assembly with a new or normally functioning one Removal.
NEXT -- Continue to next step.
7. CHECK FOR DTC
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B1447 is not output.
NG -- REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY Disassembly
OK -- END (AIR CONDITIONING AMPLIFIER ASSEMBLY IS FAULTY)