AIR CONDITIONING SYSTEM, Diagnostic DTC:B1442/42

DESCRIPTION

The No. 1 blower damper servo sub-assembly (air inlet) 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 air inlet mode selection air inlet control damper to any position, which controls the intake air settings (FRESH, FRESH/RECIRCULATION, and RECIRCULATION).

The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

WIRING DIAGRAM

PROCEDURE

1. READ VALUE USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the GTS on.

   4. Operate the R/F (Recirculation/Fresh) switch.

   5. Enter the following menus: Body Electrical / Air Conditioner / Data List.

   6. Check the value(s) by referring to the table below.

      Air Conditioner

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Air Inlet Damper Actual Pulse	No. 1 blower damper servo sub-assembly (air inlet) actual pulse / Min.: 0, Max.: 255	for LHD: RECIRCULATION: 19 (pulse) FRESH: 7 (pulse) for RHD: RECIRCULATION: 7 (pulse) FRESH: 25 (pulse)	-

      OK
      The display is as specified in the Normal Condition column.

      Result
      Result Proceed to NG A OK (When troubleshooting according to Problem Symptoms Table) B OK (When troubleshooting according to the DTC) C

   
   

   B

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

   C

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   A

2. PERFORM ACTIVE TEST USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the GTS on.

   4. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

   5. Check the operation by referring to the table below.

      Air Conditioner

      Tester Display	Test Part	Control Range	Diagnostic Note
      Air Inlet Damper Targ Pulse	No. 1 blower damper servo sub-assembly (air inlet) target pulse	Min.: 0, Max.: 255	for LHD: Operates between 7 to 19 pulses for RHD: Operates between 7 to 25 pulses

      OK
      Recirculation damper position changes in accordance with each control range.

   
   

   OK

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   NG

3. INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (AIR INLET)

   
   

   1. Replace the No. 1 blower damper servo sub-assembly (air inlet) Click here.

      Tech Tips

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or known good one and check that the condition returns to normal.

   2. Check for the DTC.

      Result
      Result Proceed to DTC B1442/42 is output A DTC B1442/42 is not output B

   
   

   B

   END (NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY WAS DEFECTIVE)

   A

4. INSPECT AIR CONDITIONING HARNESS ASSEMBLY

   
   

   1. Replace the air conditioning harness assembly Click here.

      Tech Tips

      Since the air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning harness assembly with a new or known good one and check that the condition returns to normal.

   2. Check for the DTC.

      Result
      Result Proceed to DTC B1442/42 is output A DTC B1442/42 is not output B

   
   

   A

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   B

   END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)