Dodge RAM TRUCK 1500 1995 Service Manual page 1146

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GENERAL
D I A G N O S I S — E X C E P T D I E S E L
B R
IAC
MOTOR
IAC
MOTOR
TOOL
CONNECTOR
IAC
MOTOR
CONNECTOR
TO
BATTERY
SPECIAL
TOOL 7558
J9314-115
Fig. 40 IMC Motor Testing—Typical Tool Hook-Up
LOW position. The engine speed should decrease.
(a) If the engine speed changes while using the
exerciser tool, the IAC motor is functioning prop­
erly. Disconnect the exerciser tool and connect the
IAC stepper motor wire connector to the stepper
motor.
(b) If the engine speed does not change, turn the
ignition OFF and proceed to step (6). Do not dis­
connect exerciser from the IAC stepper motor.
(6) Remove the IAC stepper motor from the throt­
tle body.
CAUTION: When checking IAC motor operation with
the motor removed from the throttle body, do not
extend the pintle (Fig. 41) more than 8.35 mm (.250
in). If the pintle is extended more than this amount, it
may separate from the IAC stepper motor. The IAC mo­
tor must be replaced if the pintle separates from the
motor.
(7) With the ignition OFF, cycle the exerciser tool
switch between the HIGH and LOW positions. Ob­
serve the pintle. The pintle should move in-and-out
of the motor.
(a) If the pintle does not move, replace the IAC
motor. Start the engine and test the replacement
motor operation as described in step (5).
(b) If the pintle operates properly, check the IAC
motor bore in the throttle body bore for blockage
and clean as necessary. Install the IAC motor and
retest. If blockage is not found, refer to the DRB
scan tool and the appropriate Powertrain Diagnos­
tics Procedures service manual.
IDLE AIR
CONTROL STEPPER
MOTOR
WIRE HARNESS
CONNECTION
PINTLE J9314-116
Fig. 41 IAC Stepper Motor Pintle—Typical
R E L A Y S — O P E R A T I O N / T E S T I N G
To perform a complete test of a relay and its cir­
cuitry, refer to DRB scan tool and appropriate Pow­
ertrain Diagnostics Procedures manual. To test the
relay only, refer to the following:
OPERATION
The following operations/tests apply to these
relays only: Automatic Shutdown (ASD) and Fuel
Pump. For operations/tests on all other relays, refer
to the appropriate section of this service manual.
These relays are located in the power distribution
center (PDC). The PDC is located in the engine com­
partment (Fig. 42). For the location of this relay
within the PDC, refer to PDC cover.
POWER
DISTRIBUTION
CENTER
(PDC)
J9414-10
Fig. 42 Power Distribution Center (PDC) Location
The relay terminal numbers (Fig. 43) can be found
on the bottom of the relay.
• Terminal number 30 is connected to battery volt­
age and can be switched or B+ (hot) at all times.
• The center terminal number 87A is connected (a
circuit is formed) to terminal 30 in the de-energized
(normally OFF) position.