Hi all again. I have been working on a Mercedes A Class A160. The customer rang up to say that it would not start after leaving it parked up for four hours. I went and checked to find that when key was turned the display read "start error". I removed floor panel to access battery and fuses. Tested and found battery to be at 12.5 Volts. Windows lights and central locking is all working. When I plugged in diagnostics I recorded 18 fault codes. I disconnected the battery terminal and refitted, turned the key and it would start but go into limp mode. The throttle pedal would not respond. I have tried his spare key and operated the immobilizer in glove box but still not starting.
One thing I did find was with data on my diagnostics the battery would show only 8 Volts. If I disconnect the coil pack then it would read 12 Volts is this correct? I have also removed the battery to recharge and test, only to find a plug connector with two wires ( purple white and Blue) The blue wire was corroded and broken. At first I thought that this was the fault. Repaired but still the same. The chassis No on this vehicle is WDB1680332J453425.