Dodge ram truck 3500 1996 Service Manual page 1274

1 4 - 4 0 FUEL SYSTEM B R
DESCRIPTION AND OPERATION (Continued)
Fig. 23 Throttle Body Air Control Passage—3.9U
5.2U5.9L Engines
the air control passage. The IAC motor is positioned
when the ignition key is turned to the On position.
A (factory adjusted) set screw is used to mechani­
cally limit the position of the throttle body throttle
plate. Never attempt to adjust the engine idle
speed using this screw. All idle speed functions are
controlled by the PCM.
Fig. 24 Idle Air Control Motor Location—8.0L Engine
IGNITION COIL—3.9L/5.2L/5.9L ENGINES—PCM
OUTPUT
System voltage is supplied to the ignition coil pos­
itive terminal. The powertrain control module (PCM)
operates the ignition coil. Base (initial) ignition
timing is not adjustable. The PCM adjusts ignition
timing to meet changing engine operating conditions.
The ignition coil is located near the front of the
right cylinder head (Fig. 26).
Refer to Group 8D, Ignition System for additional
information.
VACUUM
FITTING
PASSAGE CONTROL (IAC)
MOTOR
VIEW FROM BOTTOM
l Q A
,
A A Q
Fig. 25 Idle Air Control Passage—8.0L Engine
Fig. 26 Ignition Coil—3.9U5.2U5.9L Engines-
Typical (3.9L Shown)
IGNITION COILS—8.0L ENGINE—PCM OUTPUTS
System voltage is supplied to each of the five igni­
tion coil positive terminals. The powertrain control
module (PCM) operates the 5 paired ignition coils.
Base (initial) ignition timing is not adjustable.
The PCM adjusts ignition timing to meet changing
engine operating conditions.
The ignition coil pack is located above the right
engine valve cover (Fig. 27).
Refer to Group 8D, Ignition System for additional
information.