BUS IC Communication Malfunction

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1497/97: BUS IC Communication Malfunction
B1497/97 - BUS IC Communication Malfunction

DESCRIPTION

The air conditioning harness assembly connects the air conditioning amplifier assembly and the servo motors. The air conditioning amplifier assembly supplies power and sends operation instructions to each servo motor through the air conditioning harness assembly. Each servo motor sends damper position information to the air conditioning amplifier assembly.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Active test.

(e) Check the operation by referring to the table below.

Air Conditioner





OK:

Arm of the damper servo motor selected in the Active Test moves smoothly.

(f) According to the test result, proceed to the next step.

Result:





B -- REPLACE AIR CONDITIONING HARNESS ASSEMBLY
A -- Continue to next step.

2. SYSTEM CHECK

(a) According to the test result, proceed to the next step.

Result:





B -- REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR MIX (FOR PASSENGER SIDE))

C -- REPLACE NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (AIR INLET)

D -- REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR OUTLET)
A -- Continue to next step.

3. REPLACE NO. 2 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR MIX (FOR DRIVER SIDE))

(a) Replace the No. 2 air conditioning radiator damper servo sub-assembly (air mix (for driver side)) Disassembly.

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

(b) Check for the DTC.

Result:





B -- REPLACE AIR CONDITIONING HARNESS ASSEMBLY

A -- END

4. REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR MIX (FOR PASSENGER SIDE))

(a) Replace the No. 1 air conditioning radiator damper servo sub-assembly (air mix (for passenger side)) Disassembly.

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

(b) Check for the DTC.

Result:





B -- REPLACE AIR CONDITIONING HARNESS ASSEMBLY

A -- END

5. REPLACE NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (AIR INLET)

(a) Replace the No. 1 blower damper servo sub-assembly (air inlet) Disassembly.

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

(b) Check for the DTC.

Result:





B -- REPLACE AIR CONDITIONING HARNESS ASSEMBLY

A -- END

6. REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR OUTLET)

(a) Replace the No. 1 air conditioning radiator damper servo sub-assembly (air outlet) Disassembly.

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

(b) Check for the DTC.

Result:





B -- REPLACE AIR CONDITIONING HARNESS ASSEMBLY

A -- END

7. REPLACE AIR CONDITIONING HARNESS ASSEMBLY

(a) Replace the air conditioning harness assembly Disassembly.

HINT
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 a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result:





B -- CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

A -- END

8. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

(a) Disconnect the I77 air conditioning amplifier assembly connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal