Jeep 1997 Grand Cherokee Service Manual page 1245

ZG
DESCRIPTION AND OPERATION (Continued)
Circuit K22 delivers the TPS signal to the PCM.
Circuit K22 connects to cavity A23 of the PCM.
The PCM provides a ground for the throttle posi-
tion sensor signal (circuit K22) through circuit K4.
Circuit K4 connects to cavity A4 of the PCM.
HELPFUL INFORMATION
Refer to Group 14 for throttle position sensor oper-
ation.
Circuit K25 splices to supply 5 volts to the mani-
fold absolute pressure sensor, camshaft position sen-
sor, and crankshaft position sensor.
Circuit K4 splices to supply ground for the signals
from the following:
• Battery temperature sensor
• Camshaft position sensor
• Crankshaft position sensor
• Downstream heated oxygen sensor
• Engine coolant temperature sensor
• Fuel pump module
• Intake air temperature sensor
• Manifold absolute pressure sensor
• Oil pressure sensor
• Powertrain control module
• Transmission solenoid assembly
• Upstream heated oxygen sensor
• Vehicle speed control switch
• Vehicle speed sensor
ACCELERATOR PEDAL POSITION SENSOR
(DIESEL)
Power for the accelerator pedal position sensor is
supplied by the Powertrain Control Module (PCM) on
circuit K6. This is a 5 volt feed from the PCM.
Circuit K22 provides the pedal position input to
the PCM. Ground for the sensor is supplied from the
PCM on circuit K4.
LOW IDLE POSITION SWITCH (DIESEL)
Circuit K151 connects from the Powertrain Control
Module (PCM) to the low idle position switch. This
circuit provides the low idle switch input.
Ground for the switch is provided on circuit K4.
MANIFOLD ABSOLUTE PRESSURE SENSOR
From the Powertrain Control Module (PCM), cir-
cuit K25 supplies 5 volts to the manifold absolute
pressure (MAP) sensor. Circuit K25 connects to cav-
ity A17 of the PCM.
Circuit K70 delivers the MAP signal to the PCM.
Circuit K70 connects to cavity A27 of the PCM.
The PCM provides a ground for the MAP sensor
signal (circuit K70) through circuit K4. Circuit K4
connects to cavity A4 of the PCM.
HELPFUL INFORMATION
Refer to Group 14 for MAP sensor operation.
8W - 30 FUEL/IGNITION SYSTEMS
Circuit K25 splices to supply 5 volts to the cam-
shaft position sensor, crankshaft position sensor and
throttle position sensor.
Circuit K4 splices to supply ground for the signals
from the following:
• Battery temperature sensor
• Camshaft position sensor
• Crankshaft position sensor
• Downstream heated oxygen sensor
• Engine coolant temperature sensor
• Fuel pump module
• Intake air temperature sensor
• Oil pressure sensor
• Powertrain control module
• Throttle position sensor
• Transmission solenoid assembly
• Upstream heated oxygen sensor
• Vehicle speed control switch
• Vehicle speed sensor
MASS AIR FLOW SENSOR (DIESEL)
When the ignition switch is in the START or RUN
position, it connects Circuit A1 from fuse 8 in the
Power Disstribution Center (PDC) to circuit A21. Cir-
cuit A21 powers circuit F99 through PDC fuse 18.
Circuit F99 feeds the mass air flow sensor.
Circuit K155 provides the input to the PCM.. A
sensor ground is provided by the PCM on circuit K4.
Ground is also provided on circuit Z1.
INTAKE AIR TEMPERATURE SENSOR
The intake air temperature sensor provides an
input to the Powertrain Control Module (PCM) on
circuit K21. Circuit K21 connects to cavity A15 of the
PCM.
From circuit K21, the intake air temperature sen-
sor draws voltage from the PCM. The sensor is a
variable resistor. As intake air temperature changes,
the resistance in the sensor changes, causing a
change in current draw.
The PCM provides a ground for the intake air tem-
perature sensor signal (circuit K21) through circuit
K4. Circuit K4 connects to cavity A4 of the PCM.
HELPFUL INFORMATION
Circuit K4 splices to supply ground for the signals
from the following:
• Battery temperature sensor
• Camshaft position sensor
• Crankshaft position sensor
• Downstream heated oxygen sensor
• Engine coolant temperature sensor
• Fuel pump module
• Manifold absolute pressure sensor
• Oil pressure sensor
• Powertrain control module
• Throttle position sensor
8W - 30 - 37