| Last Modified: 08-21-2023 | 6.11:8.1.0 | Doc ID: RM100000001A3OB |
| Model Year Start: 2019 | Model: Avalon HV | Prod Date Range: [04/2018 - ] |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1497; Communication Malfunction (Bus Ic); 2019 - 2022 MY Avalon HV [04/2018 - ] | ||
|
DTC |
B1497 |
Communication Malfunction (Bus Ic) |
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.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
Memory |
|---|---|---|---|---|
|
B1497 |
Communication Malfunction (Bus Ic) |
Error or open in communication line |
|
Memorized (10 sec. or more)* |
- *: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
WIRING DIAGRAM
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) Perform the Active Test according to the display on the Techstream.
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
Measurement Item |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Air Outlet Servo Pulse (D) |
No. 3 air conditioning radiator damper servo sub-assembly pulse |
Min.: 128 Max.: 383 |
Operates between 164 and 278 pulses |
|
Air Outlet Servo Pulse (P) |
No. 1 air conditioning radiator damper servo sub-assembly (front passenger side mode) pulse |
Min.: 128 Max.: 383 |
Operates between 234 and 348 pulses |
|
A/O Servo Pulse(Rr D) |
No. 2 air conditioning radiator damper servo sub-assembly pulse |
Min.: 128 Max.: 383 |
Operates between 158 and 260 pulses |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
Air Outlet Servo Pulse (D) |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
Air Outlet Servo Pulse (P) |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
A/O Servo Pulse(Rr D) |
|
Result |
Proceed to |
|---|---|
|
All of the damper servo motors are malfunctioning |
A |
|
One of the damper servo motors is malfunctioning |
B |
| B |
|
|
|
2. |
PERFORM ACTIVE TEST USING TECHSTREAM |
(a) Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.
(b) Connect the Techstream to the DLC3.
(c) Turn the power switch on (IG).
(d) Turn the Techstream on.
(e) Enter the following menus: Body Electrical / Air Conditioner / Active test.
(f) Perform the Active Test according to the display on the Techstream.
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
Measurement Item |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
A/O Servo Pulse(Rr D) |
No. 2 air conditioning radiator damper servo sub-assembly pulse |
Min.: 128 Max.: 383 |
Operates between 158 and 260 pulses |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
A/O Servo Pulse(Rr D) |
OK:
The damper servo motor operates smoothly.
| OK |
|
REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY
|
![2019 MY Avalon HV [04/2018 - 08/2019]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT (for HV Model): DISASSEMBLY](/t3Portal/stylegraphics/info.gif)
|
|
3. |
INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY |
|
*a |
Component with harness connected (Air Conditioning Amplifier Assembly) |
NOTICE:
When inspecting the air conditioning amplifier assembly, do not bring the tester probes too close to each other as a short circuit may occur.
(a) Disconnect the z9 air conditioning amplifier assembly connector.
(b) Measure the voltage and resistance according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
z9-4 (B BUS) - Body ground |
Power switch on (IG) |
11 to 14 V |
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
z9-2 (BUS G) - Body ground |
Always |
Below 1 Ω |
(c) Turn the power switch on (IG).
(d) Using an oscilloscope, check the waveform.
|
Item |
Content |
|---|---|
|
Terminal No. |
z9-3 (BUS) - z9-2 (BUS G) |
|
Tool Setting |
2 V/DIV., 2 ms./DIV. |
|
Condition |
Power switch on (IG) |
OK:
Waveform is similar to that shown in the illustration.
HINT:
The waveform varies with the blower speed.
| OK |
|
REPLACE AIR CONDITIONING HARNESS ASSEMBLY
|
| NG |
|
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
|
|
4. |
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) Perform the Active Test according to the display on the Techstream.
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
Measurement Item |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Air Outlet Servo Pulse (D) |
No. 3 air conditioning radiator damper servo sub-assembly pulse |
Min.: 128 Max.: 383 |
Operates between 164 and 278 pulses |
|
Air Outlet Servo Pulse (P) |
No. 1 air conditioning radiator damper servo sub-assembly (front passenger side mode) pulse |
Min.: 128 Max.: 383 |
Operates between 234 and 348 pulses |
|
A/O Servo Pulse(Rr D) |
No. 2 air conditioning radiator damper servo sub-assembly pulse |
Min.: 128 Max.: 383 |
Operates between 158 and 260 pulses |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
Air Outlet Servo Pulse (D) |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
Air Outlet Servo Pulse (P) |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
A/O Servo Pulse(Rr D) |
|
Result |
Proceed to |
|---|---|
|
Only the No. 1 air conditioning radiator damper servo sub-assembly does not operate |
A |
|
Only the No. 2 air conditioning radiator damper servo sub-assembly does not operate |
B |
|
Only the No. 3 air conditioning radiator damper servo sub-assembly does not operate |
|
|
Only the No. 3 air conditioning radiator damper servo sub-assembly operates |
| B |
|
REPLACE AIR CONDITIONING HARNESS ASSEMBLY
|
|
|
5. |
INSPECT AIR CONDITIONING HARNESS ASSEMBLY (AIR CONDITIONING AMPLIFIER ASSEMBLY - NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY) |
(a) Disconnect the z9 air conditioning amplifier assembly connector.
(b) Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
z9-2 (BUS G) - A-3 (GND) |
Always |
Below 1 Ω |
|
z9-3 (BUS) - A-2 (LIN) |
Always |
Below 1 Ω |
|
z9-4 (B BUS) - A-1 (+B) |
Always |
Below 1 Ω |
| OK |
|
REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY
|
| NG |
|
REPLACE AIR CONDITIONING HARNESS ASSEMBLY
|
|
|