BMW X5 E70 engine ground cable and starting fault
Where is the engine ground cable on the X5 E70?
The ground cable runs on the driver's side above the driveshaft from the engine lug to the frame rail. On the 3.0sd the original cable is about 22 cm long.
What happens when the ground cable rots?
The cable can turn to dust, after which the starter does not turn or starting is unreliable and the glow plug fault codes stay on. After the ground is renewed, the fault codes can be cleared. If the starter does not turn even though the ground is fine, the fault can also be in the positive cable running from the battery to the engine bay. In that case a workshop investigates the locking and starting electronics with a diagnostic tool.
How do you repair a rotted ground cable?
Replace the cable with a new one and clean the contact surfaces. The replacement cable used was 55 cm long and was installed between the alternator lug and the terminal in the engine bay. Glow plug fault codes do not show on a warm engine unless they are tested in that state.