DESCRIPTION
This DTC is stored when the engine switch power source supply line is open or shorted.
DTC Code |
DTC Detection Condition |
Trouble Area |
---|---|---|
B278A |
The engine switch power source supply line is open or shorted. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Before replacing the certification ECU, refer to Registration (See page
).
PROCEDURE
1. |
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ENGINE SWITCH) |
(a) Disconnect the F79 ECU connector.
(b) Disconnect the F71 switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
F79-28 (VC5) - F71-14 (VC5) |
Always |
Below 1 Ω |
F79-36 (AGND) - F71-8 (AGND) |
||
F79-28 (VC5) or F71-14 (VC5) - Body ground |
Always |
10 kΩ or higher |
F79-36 (AGND) or F71-8 (AGND) - Body ground |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
2. |
CHECK CERTIFICATION ECU |
(a) Using an oscilloscope, check the waveform. Measurement Condition
OK: Waveform is output normally (refer to illustration). Text in Illustration
|
|
OK | ![]() |
REPLACE ENGINE SWITCH |
NG | ![]() |
REPLACE CERTIFICATION ECU |
Adjustment
ADJUSTMENT
PROCEDURE
1. CHECK BRAKE PEDAL HEIGHT
(a) Check the brake pedal height.
Pedal height from Floor panel:
158.8 to 168.8 mm (6.25 to 6.46 in.)
Text in Illustration
*1
Rod Operating Adapter
...
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
Use the following procedures to troubleshoot the Safety Connect system.
*: Use the Techstream.
PROCEDURE
1.
VEHICLE BROUGHT TO WORKSHOP
NEXT
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