Saab 9000 - Page 32

Ground
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Ground
Pins 24 and 25 of the engine control module are con-
nected to ground at grounding point G7P. The igni-
tion discharge module is also grounded at grounding
point G7P.
The engine will not start unless it is connected to
ground.
Sensor ground
The crankshaft position sensor, manifold absolute
pressure sensor, intake air temperature sensor, en-
gine coolant temperature sensor and
throttle position sensor are connected to ground via
pin 67 of the control module.
The leads connected to the crankshaft position sen-
sor and the leads from the oxygen sensors are also
screened via pin 67 of the engine control module.
The engine will not start without sensor ground.
Technical Description 29
271
271
203
67
L--------4,,&.j!C-----166
G7P
Reference ground
25
24
589
On pin 66 the ECM receives reference ground from
the sensor ground lead so that it can measure the en-
gine coolant temperature with extra precision. Drive-
ability problems while the engine is warming up will
occur if reference ground is not connected to pin 66.
The engine control module receives reference
ground on pin 47 from the two heated oxygen sen-
sors.
Saab 9000
I