- Rear air mix control servo motor
- Rear air conditioning harness
- Harness or connector between rear air conditioning harness and air conditioning amplifier
- Air conditioning amplifier
| Last Modified: 04-05-2023 | 6.11:8.1.0 | Doc ID: RM100000000ZPD5 |
| Model Year Start: 2017 | Model: Sienna | Prod Date Range: [08/2016 - ] |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1447/47; Rear Air Mix Damper Control Servo Motor Circuit; 2017 - 2020 MY Sienna [08/2016 - ] | ||
|
DTC |
B1447/47 |
Rear Air Mix Damper Control Servo Motor Circuit |
DESCRIPTION
The rear air mix control servo motor sends pulse signals to indicate the damper position to the air conditioning amplifier. The air conditioning amplifier activates the motor (normal or reverse) based on these signals to move the rear air mix damper to any position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted, and the temperature of the air blowing toward the rear is controlled.
The air conditioning amplifier communicates with the servo through a communication/driver IC and wiring assembly called the rear air conditioning harness.
HINT:
Confirm that there are no mechanical problems because this DTC can be output when either a damper link or the damper is mechanically locked.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
B1447/47 |
Rear air mix damper position does not change even if air conditioning amplifier operates rear air mix control servo motor |
|
WIRING DIAGRAM
PROCEDURE
|
1. |
READ VALUE USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Operate the rear side temperature adjustment switch.
(e) Enter the following menus: Body Electrical / Air Conditioner / Data List.
(f) Check the value(s) by referring to the table below.
Air Conditioner
|
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
Air Mix Servo Targ Pulse (R) |
Rear air mix servo motor target pulse / Min.: 128 Max.: 383 |
MAX. COLD: 137 (pulse) MAX. HOT: 182 (pulse) |
- |
|
Air Mix Servo Actual Pulse (R) |
Rear air mix servo motor actual pulse / Min.: 128 Max.: 383 |
MAX. COLD: 137 (pulse) MAX. HOT: 182 (pulse) |
- |
OK:
The display is as specified in the Normal Condition column.
Result
|
Result |
Proceed to |
|---|---|
|
NG |
A |
|
OK (When troubleshooting according to Problem Symptoms Table) |
B |
|
OK (When troubleshooting according to the DTC) |
C |
| B |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| C |
|
|
|
2. |
PERFORM ACTIVE TEST USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Air Conditioner / Active Test.
(e) Check the operation by referring to the table below.
Air Conditioner
|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Rear Air Mix Servo Targ Pulse |
Rear air mix servo target pulse |
Min.: 128, Max.: 383 |
- |
OK:
Air temperature changes in accordance with each control range.
| OK |
|
|
|
3. |
CHECK HARNESS AND CONNECTOR (REAR AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER) |
(a) Disconnect the L23 rear air conditioning harness connector.
(b) Disconnect the D186 air conditioning amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
L23-3 (RBUS) - D186-1 (RBUS) |
Always |
Below 1 Ω |
|
L23-4 (RBBU) - D186-27 (RBBU) |
Always |
Below 1 Ω |
|
L23-2 (RBUG) - D186-25 (RBUG) |
Always |
Below 1 Ω |
|
D186-1 (RBUS) - Body ground |
Always |
10 kΩ or higher |
|
D186-27 (RBBU) - Body ground |
Always |
10 kΩ or higher |
|
D186-25 (RBUG) - Body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4. |
INSPECT REAR AIR MIX CONTROL SERVO MOTOR |
(a) Replace the rear air mix control servo motor (See page
![2016 - 2020 MY Sienna [12/2015 - ]; HEATING / AIR CONDITIONING: REAR AIR CONDITIONING UNIT: DISASSEMBLY](/t3Portal/stylegraphics/info.gif)
).
HINT:
Since the rear air mix control servo motor cannot be inspected while it is removed from the vehicle, replace the rear air mix control servo motor with a new or a known good one and check that the condition returns to normal.
(b) Check for the DTC.
Result
|
Result |
Proceed to |
|---|---|
|
DTC B1447/47 is output |
A |
|
DTC B1447/47 is not output |
B |
| B |
|
|
|
5. |
INSPECT REAR AIR CONDITIONING HARNESS |
(a) Replace the rear air conditioning harness (See page
).
HINT:
Since the rear air conditioning harness cannot be inspected while it is removed from the vehicle, replace the rear air conditioning harness with a new or a known good one and check that the condition returns to normal.
(b) Check for the DTC.
Result
|
Result |
Proceed to |
|---|---|
|
DTC B1447/47 is output |
A |
|
DTC B1447/47 is not output |
B |
| A |
|
| B |
|
|
|