Dtc B278A Short To Gnd In Immobiliser System Power Source Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK WIRE HARNESS (CERTIFICATION ECU - ENGINE SWITCH)
CHECK HARNESS AND CONNECTOR
CHECK HARNESS AND CONNECTOR
DTC B278A Short to GND in Immobiliser System Power Source Circuit |
DESCRIPTION
This DTC is output 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
| - Wire harness
- Engine switch
- Certification ECU
|
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.CHECK WIRE HARNESS (CERTIFICATION ECU - ENGINE SWITCH) |
Disconnect the P33 and J31 switch connectors.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection
| Condition
| Specified Condition
|
P33-30 (VC5) - J31-14 (VC5)
| Always
| Below 1 Ω
|
P33-40 (AGND) - J31-8 (AGND)
| Always
| Below 1 Ω
|
P33-17 (E) - Body ground
| Always
| Below 1 Ω
|
P33-30 (VC5) - Body ground
| Always
| 10 kΩ or higher
|
P33-40 (AGND) - Body ground
| Always
| 10 kΩ or higher
|
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 2.CHECK HARNESS AND CONNECTOR |
Reconnect P33 ECU and J31 switch connectors.
Measures the voltage according to the value(s) in the table below.
- Standard voltage:
Tester Connection
| Condition
| Specified Condition
|
P33-30 (VC5) - Body ground
| Key is not in cabin
| Below 1 V
|
Press engine switch
| 4.6 to 5.4 V
|
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 3.CHECK HARNESS AND CONNECTOR |
Measures the resistance according to the value(s) in the table below .
- Standard resistance:
Tester Connection
| Condition
| Specified Condition
|
P33-17 (E) - Body ground
| Always
| Below 1 Ω
|
| | REPLACE CERTIFICATION ECU |
|
|
