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:

Vehicle Speed Sensor "A" (P0500)
DESCRIPTION The speed sensors detect the wheel speed and send the appropriate signals to the skid control ECU. The skid control ECU converts these wheel speed signals into a 4-pulse signal and outputs it to the TCM via the combination meter. The TCM deter ...

Power back door switch (vehicles with power back door)
Push the switch to close. Pressing the switch again while the power back door is closing will cause it to open again. However, the reverse operation cannot be performed for the first second after pressing the switch to close the door. The back door ca ...

Passenger Side Buckle Switch Circuit Malfunction (B1771)
DESCRIPTION The passenger side buckle switch circuit consists of the occupant classification ECU and front seat inner belt assembly RH. DTC B1771 is recorded when a malfunction is detected in the passenger side buckle switch circuit. Troubleshoot DTC B1 ...