Ground

Ground

Power ground

The following are grounded to grounding point G7:

•	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.

•	Crankshaft position sensor and its screen

•	Manifold absolute pressure sensor

•	Charge air absolute pressure sensor

•	EVAP pressure sensor

•	Intake air temperature sensor

•	Temperature sensor, engine coolant

•	Oxygen sensor screens

•	Pedal position sensors

•	Throttle position sensor 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

•	The engine will not start if the power ground is missing and the diagnostic tool will not be able to make contact with the system.

•	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 the reference ground is missing, diagnostic trouble code P0134 will be generated.