1999 DODGE RAM Service Repair Manual

WARNING: Vehicle interior will contain sodium hydroxide powder, a
by-product of air bag deployment. Since this powder can
irritate skin, eyes, nose, or throat, be sure to wear
safety glasses, rubber gloves and long-sleeved shirt
during clean-up.
1) Begin clean-up by putting tape over air bag exhaust vent,
so no additional powder will escape into vehicle interior. Remove air
bag modules. Use a vacuum cleaner to remove any residual powder from
vehicle interior. To avoid kneeling or sitting on a non-cleaned area,
clean from outside vehicle and work your way inside.
2) Remove any residual powder from A/C-heater outlets. Turn
blower motor to low for a few minutes and exit vehicle. Turn blower
off. Vacuum any additional powder expelled from plenum. Vacuum
interior a second time to recover all powder.
DEPLOYED AIR BAG
Dispose of deployed air bag module as any other part. No
special disposal procedure is required.
UNDEPLOYED AIR BAG
NOTE: Information on passenger-side air bag deployment is not
available from manufacturer.
Procedure 1: In-Vehicle Deployment (Driver-Side Air Bag)
1) Use this procedure if scrapping a vehicle with an
undeployed air bag. This procedure assumes that air bag wiring is
intact.
2) Disconnect and shield negative battery cable. Disconnect
2-pin clockspring at base of steering column. Cut 2-pin clockspring
connector of at clockspring side of harness.
3) Strip 1" (25 mm) of insulation from wire ends. Make a
harness consisting of 2 wires 20 feet or longer. Connect 20-foot wires
to clockspring harness. Ensure there are no loose parts in passenger
compartment and no one is within 20 feet of vehicle.
4) Staying at least 20 feet away from vehicle, connect other
2 ends of 20 foot wires to terminals of a 12-volt battery. When
deployment is achieved, loud bang will be heard and air bag will
inflate. After air bag module deploys, let module cool and dust settle
before approaching. If air bag fails to deploy, go to PROCEDURE 2.
Procedure 2: Remote Deployment (Driver-Side Air Bag)
1) Use this procedure if scrapping a vehicle with a live air
bag, but a problem in electrical system prevent deployment with air
bag still installed in vehicle. Also use this procedure if PROCEDURE 1
was unsuccessful.
WARNING: Perform remote deployment outdoors. Never attempt to deploy
air bag module inside a building, within 20 feet of
personnel, or with air bag trim cover face down.
2) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Remove air bag
module. See DRIVER-SIDE AIR BAG MODULE under REMOVAL & INSTALLATION.
3) cut pigtail wiring harness between clockspring and air bag
as close to clockspring housing as possible. Reconnect other end of
pigtail harness back into air bag module.
4) Strip 1" (25 mm) of insulation from cut ends of harness.
Place air bag module face (trim cover) up. Connect two 20-foot wires
to end of harness wires. Move 20 feet away. Connect other end of 200-

foot wires to terminals of a 12-volt battery. After air bag module
deploys, let module cool off and allow dust to settle before
approaching.
POST-COLLISION INSPECTION
When a vehicle has been involved in a collision, certain
components of the passive restraint system must be inspected or
replaced. See PASSIVE RESTRAINT SYSTEM INSPECTION article in the
GENERAL INFORMATION section for post-collision inspection information.
REMOVAL & INSTALLATION
* PLEASE READ THIS FIRST *
WARNING: Failure to follow air bag service precautions may
result in air bag deployment and personal injury. See
SERVICE PRECAUTIONS . After component replacement,
ensure proper system operation. See SYSTEM OPERATION CHECK.
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may
exist until computer systems have completed a relearn cycle.
See COMPUTER RELEARN PROCEDURES in GENERAL INFORMATION
before disconnecting battery.
AIR BAG CONTROL MODULE (ACM)
WARNING: ACM contains impact sensor, which enables SRS to activate air
bag. To avoid accidental air bag deployment, DO NOT connect
ACM electrically to system unless it is bolted to vehicle.
Removal
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Remove bottom
of center console (ACM trim cover).
2) On M/T models, remove center console from floor panel
transmission tunnel. On A/T models, remove screws securing trim cover
to ACM mounting bracket. See Fig. 2. Pull top of trim cover rearward
to release snap clips from instrument panel support bracket.
3) On all models, loosen but do not remove screws on sides
that secure instrument panel support bracket to ACM mounting bracket.
See Fig. 3 .
4) Remove nuts securing support bracket to studs on lower
instrument panel. Disconnect wire harness retainer from hole in
support bracket. Pull top of support bracket away from instrument
panel studs and fold down over ACM until it is laying on floor panel.
Unplug wire harness connector from ACM.
CAUTION: Always replace ACM and ACM mounting bracket as an assembly.
Replacement ACM includes a NEW mounting bracket. DO NOT mount
NEW ACM to old mounting bracket.
5) Remove screws securing mounting bracket to floor panel
transmission tunnel. Remove ACM, mounting bracket and support bracket
as a unit from floor panel.
Installation
To complete installation, reverse removal procedure. Install
ACM with arrow pointing toward front of vehicle. Connect ACM
connectors, ensuring connectors are locked into position. Tighten ACM

mounting screws and support bracket nuts to 125 INCH lbs. (14 N.m). DO\
NOT connect negative battery cable at this time. Go to
SYSTEM OPERATION CHECK.
Fig. 2: Identifying ACM Trim Cover (A/T Models)
Courtesy of DaimlerChrysler Corp.
Fig. 3: Removing Air Bag Control Module
Courtesy of DaimlerChrysler Corp.
DRIVER-SIDE AIR BAG MODULE

CAUTION: When removing a deployed air bag, wear eye protection, rubber
gloves and a long-sleeve shirt. Powder residue from air bag
deployment may irritate skin and eyes.
CAUTION: Before removing steering wheel, position front wheels in
straight-ahead position and lock steering column by removing
ignition key. Failure to do so could damage clockspring or
cause clockspring to be off-centered. DO NOT hammer on
steering wheel during removal, or collapsible column could be
damaged.
Removal
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Air bag module
is mounted on face of steering wheel. Ensure wheels are pointed
straight-ahead and steering wheel is locked.
2) Remove air bag module-to-steering wheel screws from back
side of steering wheel. Lift air bag module and disconnect electrical
connectors from rear of module.
Installation
Connect air bag, cruise control and horn harness connectors
to rear of air bag module. Secure module to steering wheel. Tighten
air bag module-to-steering wheel screws to specification. See
TORQUE SPECIFICATIONS . DO NOT connect negative battery cable at this
time. Go to SYSTEM OPERATION CHECK .
PASSENGER-SIDE AIR BAG MODULE
Removal
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) Open glove box. Holding glove box door, push center of
glove box bin towards front of vehicle. Flex glove box bin far enough
so glove box stops will clear sides of instrument panel opening. Roll
glove box down until stop bumpers are beyond sides of instrument panel
opening. Release bin. Lift bottom of glove box upward to disengage
hinge hooks form hinge pins.
3) Remove 3 screws securing instrument panel glove box
opening upper trim strip to instrument panel glove box opening upper
reinforcement, then remove trim strip. Remove 4 screws that secure 2
plastic support brackets of passenger-side air bag door panel outlet
housing to glove box opening upper reinforcement.
4) Reach through and above glove box opening to access and
disconnect air bag module harness connector. Remove 2 screws securing
passenger-side air bag module front bracket to instrument panel
structural support. Remove 3 screws securing passenger-side air bag
module rear bracket to glove box opening upper reinforcement.
5) Using trim stick, gently pry passenger-side air bag door
(starting at lower left edge) away from instrument panel top cover.
Remove air bag module, air bag door and panel outlet housing and
barrel assembly from instrument panel as a unit.
Installation
To install, reverse removal procedure. Ensure air bag door is
securely attached to instrument panel. Ensure air bag harness
connector latches fully engaged. DO NOT connect negative battery cable
at this time. Go to SYSTEM OPERATION CHECK .
CLOCKSPRING
CAUTION: Failure to position wheels in the straight-ahead position
with steering wheel locked when removing steering wheel could

damage clockspring and/or require clockspring to be
readjusted.
NOTE: Clockspring is self-centering and will automatically lock in
the centered position when steering wheel is removed.
Adjustment is only required if centering position is
disturbed.
Removal
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) Clockspring is located behind steering wheel. See Fig. 1.
Ensure front wheels are in straight-ahead position. Lock steering
wheel. Remove air bag module. See AIR BAG MODULE.
3) Remove steering wheel nut. Using appropriate steering
wheel puller, remove steering wheel. When steering wheel is removed,
self-centering clockspring will automatically lock in place. Remove
upper and lower steering column shrouds to gain access to clockspring
wiring.
4) Remove knee bolster (if equipped). Disconnect Yellow 2-wa\
y
clockspring harness connector between clockspring and instrument panel
wiring harness, at base of steering column. See Fig. 13. Remove
clockspring by releasing 2 tabs on side of clockspring. Clockspring
cannot be repaired and must be replaced if faulty.
Installation
1) Snap clockspring onto steering column. If clockspring
centering adjustment is disturbed, adjust clockspring before
installing steering wheel. See CLOCKSPRING CENTERING under
ADJUSTMENTS. Connect clockspring wiring connectors. Install steering
column covers. Install knee bolster (if removed).
2) Position steering wheel on steering column. Ensure flats
on steering wheel hub fit formations on inside of clockspring. Pull
clockspring, cruise control switch (if equipped) and horn wires
through lower large holes and upper small holes in steering wheel.
3) Install steering wheel retaining nut and tighten to 45 ft.
lbs. (61 N.m). Connect horn and cruise control wires (if equipped).
Connect clockspring wire to air bag module. To ensure complete
connector connection, latching arms must be visible on top of
connector housing. DO NOT connect negative battery cable at this time.
Go to SYSTEM OPERATION CHECK .
PASSENGER AIR BAG DISARM (PAD) SWITCH
Removal & Installation
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) If vehicle is equipped with automatic transmission, turn
ignition switch to UNLOCK position, set parking brake and place
transmission selector lever in LOW position. Tilt steering column to
lowest position (if equipped). Using trim stick, gently pry around
perimeter of cluster bezel and remove bezel.
3) Open glove box. Holding glove box door, push center of
glove box bin towards front of vehicle. Flex glove box bin far enough
so glove box stops will clear sides of instrument panel opening. Roll
glove box down until stop bumpers are beyond sides of instrument panel
opening. Release bin. Lift bottom of glove box upward to disengage
hinge hooks form hinge pins.
4) Reach through glove box opening to access and disconnect 2
passenger-side air bag disarm switch harness connectors. Connectors
are attached to bracket located on inboard glove box opening
reinforcement. See Fig. 4. Remove 3 screws retaining passenger-side
air bag disarm switch bezel to instrument panel.

5) Remove 3 screws securing passenger-side disable switch to
back of switch bezel and remove switch from bezel.
6) To install, reverse removal procedure. Tighten PAD switch
mounting screws to specification. See TORQUE SPECIFICATIONS. DO NOT
connect negative battery cable at this time. Go to
SYSTEM OPERATION CHECK .
Fig. 4: Identifying PAD Switch Connectors
Courtesy of DaimlerChrysler Corp.
ADJUSTMENTS

CLOCKSPRING CENTERING
CAUTION: If rotating part of clockspring is not positioned properly
with steering column and front wheels, clockspring failure
may result. The following procedure must be used to center
clockspring.
Depress 2 plastic auto-locking tabs. See Fig. 5. Keeping
auto-locking tabs depressed, rotate clockspring rotor clockwise to end
of its travel. DO NOT apply excessive force. Rotate rotor
counterclockwise 2 1/2 turns from end of travel and release auto-
locking tabs. Ensure horn wire ends up at the top and air bag module
wire at the bottom.
Fig. 5: Centering Clockspring
Courtesy of DaimlerChrysler Corp.
TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS








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Application Ft. Lbs. (N.m)
Steering Wheel Nut ............................... 45 (61)
INCH Lbs. (N.m)
ACM Mounting Screws &
Support Bracket Nuts ........................ 125 (14.0)
Driver-Side Air Bag Module Screws .......... 80-100 (9-11)
Front Impact Sensor Screws ............... 40-50 (4.5-5.6)
PAD Switch Mounting Screws ...................... 20 (2.2)
Passenger-Side Air Bag Module Screws ............ 80 (9.0)









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DIAGNOSIS & TESTING
* PLEASE READ THIS FIRST *
WARNING: Always follow air bag service precautions to avoid air bag
deployment and possible personal injury. Refer to procedure
under SERVICE PRECAUTIONS . After component replacement,
ensure proper system operation. See SYSTEM OPERATION CHECK.
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may
exist until computer systems have completed a relearn cycle.
See COMPUTER RELEARN PROCEDURES in GENERAL INFORMATION.
NOTE: Although other scan tools are available, manufacturer
recommends using Diagnostic Readout Box (DRB) tester to
access SRS on-board diagnostics. Following diagnosis and
testing procedures are designed for use with DRB.
SELF-DIAGNOSTIC SYSTEM
SRS is monitored by Air Bag Control Module (ACM). ACM
contains safing sensor, an integral sensor in circuitry of system,
which is used to deploy air bag modules.
ACM monitors critical input and output circuits within air
bag system, ensuring they operate correctly. Some circuits are tested
continuously; others are checked under certain conditions. ACM
provides information about air bag system, through AIR BAG warning
light and DRB tester. Each circuit monitored by ACM has a
corresponding fault code or fault message assigned to it.
Active Codes
A code becomes active as soon as a malfunction is detected.
An active trouble code indicates an on-going malfunction. This means
the defect is currently there every time the ACM checks that
circuit/function. An active trouble code can not be erases. Active
codes will automatically erase when the reason for the code has been
corrected.
With the exception of warning light trouble codes or
malfunctions, when a malfunction is detected, AIR BAG warning light
remains illuminated for a minimum of 12 seconds or as long as the
malfunction is present.
Stored Codes
Trouble codes are automatically stored in ACM memory as soon