Ground
Ground
Power ground
The following are grounded to grounding point G7:
^ control module pins 25, 47 and 62
^ mass air flow sensor
^ ignition discharge module.
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
^ Differential pressure sensor, tank
^ Intake air temperature sensor
^ Temperature sensor, engine coolant
^ Oxygen sensor screens
^ Pedal position sensors
^ Throttle position sensor
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.
^ The engine will not start if the sensor ground is missing and the throttle will go into limp-home mode. As the two sensor ground outputs are coupled together internally in the throttle body, there will be no symptoms if a break should occur in only one of them.
^ If the reference ground is missing, diagnostic trouble code P0134 will be generated.