DTC 97

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): B1497/97: BUS IC Communication Malfunction
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. The A/C amplifier communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR

(a) Remove the A/C amplifier.

(b) Disconnect the connector from the A/C amplifier.

(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.

2. INSPECT AIR CONDITIONING AMPLIFIER

(a) Reconnect the connector to the A/C amplifier.





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

Standard Resistance:





Text in Illustration





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

3. INSPECT AIR CONDITIONING AMPLIFIER

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





Standard Voltage:





Text in Illustration





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

4. REPLACE AIR CONDITIONING HARNESS

(a) Replace the air conditioning harness Disassembly.

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

(b) Check for DTCs.

Result:





B -- REPLACE AIR CONDITIONING AMPLIFIER Removal

A -- END