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 |
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
Use the following procedure to troubleshoot the front power seat control
system.
*: Use the Techstream.
PROCEDURE
1.
VEHICLE BROUGHT TO WORKSHOP
NEXT ...
Power back window
The power back window can be opened and closed using the switch or key.
From inside the vehicle
1. Closing
2. One-touch closing*
3. Opening
4. One-touch opening* *: Pressing the switch in the opposite direction will stop
window travel partway.
Fro ...