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) |
Inspection
INSPECTION
PROCEDURE
1. INSPECT FRONT DIFFERENTIAL CASE
(a) Using SST, rotate the front differential side gear as shown in the
illustration.
SST: 09528-52010
09528-05030
Standard:
The front differential side gear does not lock wh ...
Precaution
PRECAUTION
1. PRECAUTION FOR DISCONNECTING THE BATTERY CABLE
NOTICE:
When disconnecting the cable from the negative (-) battery terminal, initialize
the following systems after the cable is reconnected.
System Name
See Procedure
...
Tachometer Malfunction
DESCRIPTION
In this circuit, the meter CPU receives engine speed signals from the ECM using
the CAN communication system (CAN No. 1 Bus). The meter CPU displays the engine
speed calculated based on the data received from the ECM.
WIRING DIAGRAM
PROCED ...