- Certification ECU (smart key ECU)
- Steering lock actuator assembly (steering lock ECU)
- Harness and connector
- Power management control ECU
| Last Modified: 04-05-2023 | 6.11:8.1.0 | Doc ID: RM100000000VJEZ |
| Model Year Start: 2016 | Model: Sienna | Prod Date Range: [12/2015 - ] |
| Title: NETWORKING: LIN COMMUNICATION SYSTEM: B2785; Communication Malfunction between ECUs Connected by LIN; 2016 - 2020 MY Sienna [12/2015 - ] | ||
|
DTC |
B2785 |
Communication Malfunction between ECUs Connected by LIN |
DESCRIPTION
The certification ECU (smart key ECU) intermittently monitors the LIN communication bus between the components related to certification. DTC B2785 is stored when a malfunction in the LIN communication bus between the components related to certification is detected continuously 3 times.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
B2785 |
The certification ECU (smart key ECU) detects a malfunction in the LIN communication bus between components related to certification continuously 3 times. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
When using the Techstream with the ignition switch off to troubleshoot:
Connect Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.
PROCEDURE
|
1. |
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU) - EACH ECU) |
Text in Illustration
|
*a |
Component without harness connected (Instrument Panel Junction Block Assembly) |
*b |
Front view of wire harness connector (to Steering Lock Actuator Assembly (Steering lock ECU)) |
|
*c |
Front view of wire harness connector (to Power Management Control ECU) |
- |
- |
(a) Disconnect the D88 certification ECU (smart key ECU) connector.
(b) Disconnect the D29 steering lock actuator assembly (steering lock ECU) connector.
(c) Disconnect the D89 power management control ECU connector.
(d) Measure the resistance and voltage according to the value(s) in the tables below.
Standard Resistance (Check for Open):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D88-29 (LIN) - D29-5 (LIN) |
Always |
Below 1 Ω |
|
D88-29 (LIN) - D89-24 (LIN2) |
Always |
Below 1 Ω |
Standard Resistance (Check for Short):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D88-29 (LIN) - Body ground |
Always |
10 kΩ or higher |
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D88-29 (LIN) - Body ground |
Always |
Below 0.5 V |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
2. |
CHECK FOR DTC |
(a) Clear the DTC (See page
![2016 - 2020 MY Sienna [12/2015 - ]; NETWORKING: LIN COMMUNICATION SYSTEM: DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)
).
(b) Reconnect the D88 certification ECU (smart key ECU) and D89 steering lock actuator assembly (steering lock ECU) connectors.
(c) Check for DTCs.
Result
|
Result |
Proceed to |
|---|---|
|
DTC B2785 is output |
A |
|
DTC B2785 is not output |
B |
| B |
|
|
|
3. |
CHECK FOR DTC |
(a) Clear the DTC (See page
).
(b) Reconnect the D89 power management control ECU connector.
(c) Disconnect the D29 steering lock actuator assembly (steering lock ECU) connector.
(d) Check for DTCs.
Result
|
Result |
Proceed to |
|---|---|
|
DTC B2785 is output |
A |
|
DTC B2785 is not output |
B |
| A |
|
REPLACE CERTIFICATION ECU (SMART KEY ECU) (See page
|
| B |
|
|
4. |
REPLACE POWER MANAGEMENT CONTROL ECU |
(a) Temporarily replace the power management control ECU with a new or normally functioning one.
(b) Clear the DTC (See page
).
|
|
5. |
CHECK FOR DTC |
(a) Check for DTCs (See page
).
Result
|
Result |
Proceed to |
|---|---|
|
DTC B2785 is not output |
A |
|
DTC B2785 is output |
B |
| A |
|
END (POWER MANAGEMENT CONTROL ECU IS MALFUNCTIONING) |
| B |
|
REPLACE CERTIFICATION ECU (SMART KEY ECU) (See page
|
|
6. |
REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) |
(a) Temporarily replace the steering lock actuator assembly (steering lock ECU) with a new or normally functioning one (See page
).
(b) Clear the DTC (See page
).
|
|
7. |
CHECK FOR DTC |
(a) Check for DTCs (See page
).
Result
|
Result |
Proceed to |
|---|---|
|
DTC B2785 is not output |
A |
|
DTC B2785 is output |
B |
| A |
|
END (STEERING LOCK ACTUATOR ASSEMBLY IS MALFUNCTIONING) |
| B |
|
REPLACE CERTIFICATION ECU (SMART KEY ECU) (See page
|
|
|