Ground

Ground

Power ground

Grounding point G7 is used to ground the following:

•	control module pins 25, 47 and 62

•	the mass air flow sensor

•	the ignition discharge module

Sensor ground

The following sensors are grounded from control module pins 22 and 70. The two supplies are internally connected in the throttle body.

•	The crankshaft position sensor and its screening

•	The manifold absolute pressure sensor

•	The charge air absolute pressure sensor

•	The differential tank pressure sensor

•	The intake air temperature sensor

•	The engine coolant temperature sensor

•	The oxygen sensor screenings

•	The pedal position sensors

•	The throttle position sensors

Reference ground

Oxygen sensors 1 and 2 are grounded from control module pin 58.

Diagnostics

•	If no power ground is present, the engine will not start and the system cannot be contacted by the diagnostic tool.

•	If a sensor ground is missing, the engine will not start and the throttle will go into limp-home mode. As the two sensor ground outputs are internally connected in the throttle body, there will be no symptoms if there is an open circuit in one of them.

•	If no reference ground is present, diagnostic trouble code P0134 will be generated.