Toyota Venza: BUS IC Communication Malfunction (B1497/97)

Toyota Venza Service Manual / Heating / Air Conditioning / Air Conditioning System / BUS IC Communication Malfunction (B1497/97)

DESCRIPTION

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

DTC No.	DTC Detection Condition	Trouble Area
B1497/97	Communication line error or open	Air conditioning harness A/C amplifier

WIRING DIAGRAM

PROCEDURE

1.	INSPECT A/C AMPLIFIER

(a) Remove the A/C amplifier with the connectors still connected.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
z7-2 (BUS G) - Body ground	Always	Below 1 Ω

Text in Illustration

*1	Component with harness connected (A/C Amplifier)

REPLACE A/C AMPLIFIER

2.	INSPECT A/C AMPLIFIER

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
z7-4 (B BUS) - z7-2 (BUS G)	Ignition switch off	Below 1 V
z7-4 (B BUS) - z7-2 (BUS G)	Ignition switch ON	11 to 14 V
z7-3 (BUS) - z7-2 (BUS G)	Ignition switch ON	Pulse generation

Text in Illustration

*1	Component with harness connected (A/C Amplifier)

REPLACE AIR CONDITIONING HARNESS

REPLACE A/C AMPLIFIER

Compressor Solenoid Circuit (B1451/51)

DESCRIPTION In this circuit, the A/C compressor receives a refrigerant compression demand signal from the A/C amplifier. Based on this signal, the A/C compressor changes the amount of compressor o ...

Air Mix Damper Control Servo Motor Circuit (Driver Side) (B1446/46)

DESCRIPTION The air mix control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these sign ...

Other materials about Toyota Venza:

Random Access Memory (RAM) (P0604)
MONITOR DESCRIPTION The ECM continuously monitors its internal memory status. This self-check ensures that the ECM is functioning properly. It is diagnosed by internal "mirroring" of the main CPU and sub CPU to detect Random Access Memory (RAM) ...

Dtc Check / Clear
DTC CHECK / CLEAR 1. DTC CHECK/CLEAR (When Using the Techstream) (a) Check for DTCs. (1) Connect the Techstream to the DLC3. (2) Turn the ignition switch to ON. (3) Turn the Techstream on. (4) Read the DTCs following the prompts on the Techstream. Enter ...

Installation
INSTALLATION PROCEDURE 1. INSTALL ENGINE SWITCH (a) Attach the 2 claws to install the engine switch. 2. INSTALL LOWER INSTRUMENT PANEL FINISH PANEL ASSEMBLY (a) Connect the connector. ...