Model: Bora 1.8L Symptom: no car, after ignition one to two seconds automatically turn off.
    Maintenance Description: The 1552 query shows the engine control unit lock and power bus failure, and can not survive, after asking the car was hit.
    1, suspected bus wiring and control unit problems, disconnect the ABS pump, gearbox, airbags and other power bus-related components to see if there is a short circuit control unit, after the fault is still broken, so to determine the control unit no problem.
    2, with VAG1598 / 31 and VAS5051 measurement tool DSO view the waveform and found that the power bus waveform is abnormal. In the measurement of a fault phenomenon into a sporadic, because only a little bit of the battery sub-line, suspected battery near the poor contact, and then a fault to reproduce, deal with power lines and ground line fault remains the same.
    3, in accordance with conventional practice, measuring bus lines, with a multimeter and VAG1598 / 31 were connected to the control unit 58 and 60 feet to the instrument 19 and 20 feet found a 5 ohm resistance, the normal should not exceed 1.5 ohms. Because the power bus uses a star-connected mechanism, it tries to find the power bus node. The bus node should be in the vicinity of the trough, remove the deflector and then measure the line into the circuit, and further open the trench at the transition plug measurement and found that the white transition plug because the accident did not repair the white plug broken, bad contact, verified This plug is a transition plug for the power bus. The source of the fault should be here.
    For a plug, re-wiring failure into an occasional, troubleshooting.