Jeep Cherokee 2000 Service Manual - page 352
When the leading edge of the pulse ring (shutter)
enters the sync signal generator, the following occurs:
The interruption of magnetic field causes the voltage
to switch high resulting in a sync signal of approxi-
mately 5 volts.
When the trailing edge of the pulse ring (shutter)
leaves the sync signal generator, the following occurs:
The change of the magnetic field causes the sync sig-
nal voltage to switch low to 0 volts.
CAMSHAFT POSITION SENSOR—4.0L ENGINE
DESCRIPTION
The Camshaft Position Sensor (CMP) on the 4.0L
6–cylinder engine is bolted to the top of the oil pump
drive shaft assembly (Fig. 6). The sensor and drive
shaft assembly is located on the right side of the
engine near the oil filter (Fig. 7).
OPERATION
The CMP sensor contains a hall effect device called
a sync signal generator to generate a fuel sync sig-
nal. This sync signal generator detects a rotating
pulse ring (shutter) on the oil pump drive shaft (Fig.
6). The pulse ring rotates 180 degrees through the
sync signal generator. Its signal is used in conjunc-
tion with the crankshaft position sensor to differenti-
ate between fuel injection and spark events. It is also
used to synchronize the fuel injectors with their
respective cylinders.
When the leading edge of the pulse ring (shutter)
enters the sync signal generator, the following occurs:
The interruption of magnetic field causes the voltage
to switch high resulting in a sync signal of approxi-
mately 5 volts.
When the trailing edge of the pulse ring (shutter)
leaves the sync signal generator, the following occurs:
The change of the magnetic field causes the sync sig-
nal voltage to switch low to 0 volts.
IGNITION SWITCH AND KEY LOCK CYLINDER
DESCRIPTION
The electrical ignition switch is located on the
steering column. It is used as the main on/off switch-
ing device for most electrical components. The
mechanical key lock cylinder is used to engage/disen-
gage the electrical ignition switch.
Fig. 6 CMP and Oil Pump Drive Shaft—4.0L Engine
1 – CAMSHAFT POSITION SENSOR
2 – MOUNTING BOLTS (2)
3 – PULSE RING
4 – DRIVE GEAR (TO CAMSHAFT)
5 – OIL PUMP DRIVESHAFT
6 – SENSOR BASE (OIL PUMP DRIVESHAFT ASSEMBLY)
Fig. 7 CMP Location—4.0L Engine
1 – OIL FILTER
2 – CAMSHAFT POSITION SENSOR
3 – CLAMP BOLT
4 – HOLD-DOWN CLAMP
5 – MOUNTING BOLTS (2)
6 – ELEC. CONNECTOR
XJ
IGNITION SYSTEM
8D - 5
DESCRIPTION AND OPERATION (Continued)