DESCRIPTION
This DTC is stored when LIN communication between the certification ECU (smart key ECU assembly) and power management control ECU stops for more than 10 seconds.
DTC Code |
DTC Detection Condition |
Trouble Area |
---|---|---|
B278C |
No communication between the certification ECU (smart key ECU assembly) and power management control ECU for more than 10 seconds. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Connect the Techstream to the DLC3, and turn the courtesy switch on and off at 1.5-second intervals until communication between the Techstream and vehicle begins.
PROCEDURE
1. |
CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY AND BODY GROUND) |
(a) Disconnect the D43 ECU connector. |
|
(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D43-5 (GND2) - Body ground |
Always |
Below 1 Ω |
D43-6 (GND) - Body ground |
Always |
Below 1 Ω |
Standard Voltage:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D43-1 (AM22) - Body ground |
Always |
11 to 14 V |
D43-2 (AM21) - Body ground |
Always |
11 to 14 V |
*1 |
Power Management Control ECU |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
2. |
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - POWER MANAGEMENT CONTROL ECU) |
(a) Disconnect the D25 ECU connector. |
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D25-29 (LIN) - D43-24 (LIN2) |
Always |
Below 1 Ω |
D25-29 (LIN) - Body ground |
Always |
10 kΩ or higher |
*1 |
Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly)) |
*2 |
Front view of wire harness connector (to Power Management Control ECU) |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
3. |
REPLACE POWER MANAGEMENT CONTROL ECU |
(a) Replace the power management control ECU (See page
).
|
4. |
CHECK DTC OUTPUT |
(a) Clear the DTC (See page ).
(b) Recheck for DTCs.
OK:
DTC B278C is not output.
OK | ![]() |
END (POWER MANAGEMENT CONTROL ECU WAS DEFECTIVE) |
NG | ![]() |
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
Route cannot be Calculated
PROCEDURE
1.
SET DESTINATION
(a) Set another destination and check if the system can calculate the route correctly.
OK:
Route can be correctly calculated.
OK
END
NG
PROCEED T ...
Dtc Check / Clear
DTC CHECK / CLEAR
1. DTC CHECK (USING SST CHECK WIRE)
(a) Check the DTCs (Current trouble codes).
(1) Turn the ignition switch to ON, and wait for approximately 60 seconds.
(2) Using SST, connect terminals TC and CG of the DLC3.
SST: 09843-18040
NOTICE ...
Vehicle Specifications have not been Stored (B2451)
DESCRIPTION
The headlight leveling ECU assembly stores this DTC if the vehicle specifications
have not been stored in the ECU.
HINT:
The vehicle specifications are stored in the ECU at the factory.
DTC No.
DTC Detecting Condition
...