DESCRIPTION
This DTC is stored when the engine switch power source supply line is open or shorted.
DTC No. |
DTC Detection Condition |
Trouble Area |
---|---|---|
B278A |
Engine switch power source supply line is open or shorted. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
If the certification ECU (smart key ECU assembly) is replaced, register the key (See page ).
PROCEDURE
1. |
CHECK DTC OUTPUT |
(a) Clear the DTCs (See page ).
(b) Recheck for DTCs (See page ).
OK:
DTC B278A is not output.
OK |
USE SIMULATION METHOD TO CHECK |
|
2. |
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ENGINE SWITCH) |
(a) Disconnect the certification ECU (smart key ECU assembly) connector.
(b) Disconnect the engine switch connector. |
|
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D25-28 (VC5) - D13-14 (VC5) |
Always |
Below 1 Ω |
D25-36 (AGND) - D13-8 (AGND) |
Always |
Below 1 Ω |
D25-28 (VC5) - Body ground |
Always |
10 kΩ or higher |
D25-36 (AGND) - 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 Engine Switch) |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
3. |
CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
(a) Reconnect the certification ECU (smart key ECU assembly) connector.
(b) Reconnect the engine switch connector.
(c) Using an oscilloscope, check the waveform.
Waveform (Reference):
Item |
Content |
---|---|
Tester Connection |
D25-28 (VC5) - D25-36 (AGND) |
Tool Setting |
2 V/DIV., 200 ms./DIV. |
Condition |
|
OK:
Waveform is output normally (see illustration)
Result |
Proceed to |
---|---|
NG |
A |
OK (for 2GR-FE) |
B |
OK (for 1AR-FE) |
C |
*1 |
Component with harness connected (Certification ECU (Smart Key ECU Assembly)) |
*2 |
GND |
A |
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
B |
REPLACE ENGINE SWITCH |
C |
REPLACE ENGINE SWITCH |
Dtc Check / Clear
DTC CHECK / CLEAR
1. CHECK DTC
(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 / (desired system) / Trouble Codes.
(e) Check the details of the DTC(s) ...
Removal
REMOVAL
PROCEDURE
1. REMOVE UPPER CONSOLE PANEL SUB-ASSEMBLY (w/o Seat Heater System)
2. REMOVE UPPER CONSOLE PANEL SUB-ASSEMBLY (w/ Seat Heater System)
3. REMOVE NO. 2 CONSOLE BOX CARPET
4. REMOVE CONSOLE BOX ASSEMBLY
5. REMOVE AIR CONDITION ...
Power Management Control ECU Communication Stop Mode
DESCRIPTION
Detection Item
Symptom
Trouble Area
Power Management Control ECU Communication Stop Mode
"Electric Power Control" is not displayed on the CAN Bus Check
screen ...