B1497

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

DTC B1497/97 - BUS IC Communication Malfunction

DESCRIPTION

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





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK AIR CONDITIONING SYSTEM CONTROL
(a) Check that the air conditioning system control.
OK:
Air conditioning system control is normal.

Result





D -- CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)
C -- CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)
B -- REPLACE AIR CONDITIONING AMPLIFIER
A -- Continue to next step.

2. CHECK FOR DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Check for DTC Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC is not output.

NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- CHECK FOR INTERMITTENT PROBLEMS
3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)




(a) Disconnect the H24 air conditioning amplifier connector.
(b) 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. INSPECT AIR CONDITIONING AMPLIFIER




(a) Reconnect the H24 air conditioning amplifier connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.

Standard Resistance:





Standard Voltage:






NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- Continue to next step.

5. REPAIR OR REPLACE AIR CONDITIONING HARNESS
(a) Repair or replace the air conditioning harness Disassembly.
NEXT -- Continue to next step.

6. CHECK FOR DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Check for DTC Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC is not output.

NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- END
7. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)




(a) Disconnect the H67 air conditioning amplifier connector.
(b) 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.

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




(a) Disconnect the P9 rear air conditioning harness connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:





(c) Reconnect the air conditioning amplifier connector.
(d) Reconnect the rear air conditioning harness connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

9. CHECK AIR CONDITIONING AMPLIFIER




(a) Measure the resistance and voltage according to the value(s) in the table below.

Standard Resistance:





Standard Voltage:





NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- Continue to next step.

10. REPAIR OR REPLACE NO.2 AIR CONDITIONING HARNESS
(a) Repair or replace the No. 2 air conditioning harness Disassembly.
NEXT -- Continue to next step.

11. CHECK FOR DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Check for DTC Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC is not output.

NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- END