Ground

Ground

Power ground

Grounding point G7 is used to ground the following:

•	control module pins 25 and 47

•	mass air flow sensor

•	ignition discharge modules.

Sensor ground

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

•	The crankshaft position sensor and its screening

•	Manifold absolute pressure sensor

•	Charge air absolute pressure sensor

•	EVAP pressure sensor

•	Intake air temperature sensor

•	Temperature sensor, coolant

•	Oxygen sensor screens

•	Pedal position sensors

•	Throttle position sensors Note The sensor ground wires from control module pins 22 and 70 are coupled together in the throttle body.

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 the sensor ground is absent, the engine will not start and the functions being supplied will generate diagnostic trouble codes. Since the two sensor ground outputs are coupled together internally in the throttle body, no symptoms will appear if an open circuit occurs in only one of them.

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