DODGE RAM 1999 Service Repair Manual

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

as the malfunction is detected. A stored code indicates there was an
active code present at some time. However, the code currently may not
be present as an active code, although another active code could be.
When a trouble code occurs, the AIR BAG warning light
illuminates for 12 seconds minimum (even if problem existed for less
than 12 seconds). Code is stored, along with time in minutes it was
active, and number of times ignition has been cycled since problem was
detected.
When and if malfunction ceases to exist, an ignition cycle
count will be initiated for that code. If ignition cycle count reaches
100 without a reoccurrence of the same malfunction, DTC is erased and
that ignition cycle counter is reset to zero. If malfunction reoccurs
before count reaches 100, ignition cycle counter will be reset and DTC
will continue to be a stored code.
If a particular code is not active while performing
diagnostic test for that code, code diagnostic test may not locate the
source of the problem. In this case, stored code can only indicate an
area of system to inspect.
If no obvious problems are found, erase stored codes, and
with ignition on, wiggle wiring harness and connectors. Recheck for
codes periodically as you work through system. This procedure may
uncover a difficult problem to locate.
PRETEST INSPECTION & DIAGNOSTIC PROCEDURE
Following precautions and procedures must be followed:
* Always follow air bag service precautions to avoid air bag
deployment and possible personal injury. Refer to procedure
under See SERVICE PRECAUTIONS.
* After component replacement, ensure proper system operation.
See SYSTEM OPERATION CHECK .
* When testing voltage or continuity at ACM, use terminal side
(not wire end) of connector. DO NOT probe wire through
insulation.
* Always check if any TECH SERVICE BULLETINS (TSBs) apply to
vehicle.
* When using diagnostic charts, DO NOT skip any steps in chart
or incorrect diagnosis may result. Always perform
SYSTEM OPERATION CHECK after repairs are made.
* Always use most current DRB diagnostic program cartridge
available to prevent erroneous codes or test results.
* When using diagnostic charts, use DRB voltmeter unless
instructed to use an external voltmeter. Never use a test
light in place of a voltmeter.
* When performing electrical tests, prevent accidental
shorting of terminals. Such shorts can damage fuses or
components and may cause a second code (message) to be
set, making diagnosis of original problem more difficult.
* Vehicle must have a fully-charged battery and functional
charging system.
* Each time a connector is disconnected, inspect it to ensure
it is in good condition. Always focus on circuit being
tested. Dirt, water and corrosion, are most common problems
in connectors.
* Always disconnect DRB after use.
* Always disconnect DRB before charging battery.
USING DRB
1) Refer to DRB user guide for instructions and assistance
with reading trouble codes and other DRB functions. Under normal
operation DRB will display one of only 2 error messages: User-

Requested WARM boot or User-Requested COLD boot. If DRB should display
any other error message, record entire display and contact
manufacturer.
2) If DRB does not power-up, check for loose cable
connections or a bad cable. Check vehicle battery voltage (data link
connector terminal No. 16). A minimum of 11 volts is required to
adequately power DRB.
3) If all connections are proper between DRB and vehicle or
other devices, and vehicle battery is fully charged, an inoperative
DRB may be result of faulty cable or vehicle wiring.
ENTERING ON-BOARD DIAGNOSTICS
1) Before entering on-board diagnostics, refer to
PRETEST INSPECTION & DIAGNOSTIC PROCEDURE . Connect DRB to data link
connector. Data link connector (DLC) is located under left side of
instrument panel, left of steering column.
NOTE: Read active DTCs with PAD switch in both ON and OFF
positions. Always turn ignition off before changing PAD
switch positions,
2) Turn ignition switch to ON position. Exit vehicle with
DRB. Using DRB, read and record active Diagnostic Trouble Code (DTC)
data. Read and record stored DTC data. If any DTCs (fault messages)
exist, perform appropriate test.
3) If PAD switch OFF indicator fails to illuminate when in
the OFF position, go to PAD SWITCH INDICATOR PROBLEMS . If PAD switch
OFF indicator illuminates when switch is in ON position or key
cylinder does not operate, replace PAD switch.
4) Air Bag Control Module (ACM) may report any of the
following DTCs or fault messages. If the following active or stored
codes are reported by DRB, replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
* ACM OUTPUT DRIVER CIRCUIT OPEN
* ACM ACCELEROMETER
* ACM INTERNAL DIAGNOSTIC CODE #1
* WARNING LAMP DRIVER ERROR
* FIRING CAPACITOR LOW
* LOGIC CAPACITOR LOW
* SAFING SENSOR SHORTED
If the following active codes are reported by DRB, go to the
appropriate procedure under DIAGNOSTIC TESTS.
* CLUSTER MESSAGE MISMATCH
* DRIVER SQUIB CIRCUIT OPEN
* DRIVER SQUIB CIRCUIT SHORTED
* DRIVER SQUIB CIRCUIT SHORTED TO BATTERY
* DRIVER SQUIB CIRCUIT SHORTED TO GROUND
* LOSS OF IGNITION RUN ONLY
* LOSS OF IGNITION RUN/START
* NO CLUSTER CCD MESSAGE
* NO CCD COMMUNICATION
* MISSING OR INVALID VIN
* PASSENGER SQUIB CIRCUIT OPEN
* PASSENGER SQUIB CIRCUIT SHORTED
* PASSENGER SQUIB CIRCUIT SHORTED TO BATTERY
* PASSENGER SQUIB CIRCUIT SHORTED TO GROUND
* SCTM FAILURE
* SCTM MESSAGE MISMATCH
* VIN MESSAGE MISMATCH

* WARNING LAMP CIRCUIT OPEN/SHORTED
DIAGNOSTIC TESTS
* PLEASE READ THIS FIRST *
NOTE: Many of the diagnostic tests of the air bag restraint system
require voltage or resistance checks at various system
connector terminals. See Figs. 6-19.
Fig. 6: Identifying Powertrain Control Module (PCM) Connector
Terminals
Courtesy of DaimlerChrysler Corp.
Fig. 7: Identifying Instrument Cluster Connector Terminals
Courtesy of DaimlerChrysler Corp.

Fig. 8: Locating Seat Belt Control Timer Module & Main Seat Connector
Courtesy of DaimlerChrysler Corp.
Fig. 9: Identifying Seat Belt Control Timer Module (SCTM)
Connector Terminals
Courtesy of DaimlerChrysler Corp.

Fig. 10: Identifying Air Bag Control Module (ACM) Connector Terminals\
Courtesy of DaimlerChrysler Corp.
Fig. 11: Identifying Driver Squib Connector Terminals
Courtesy of DaimlerChrysler Corp.

Fig. 12: Locating Clockspring 2-Pin Connector
Courtesy of DaimlerChrysler Corp.
Fig. 13: Identifying Passenger Air Bag Disable (PAD) Switch
Connector Terminals (Switch Side)
Courtesy of DaimlerChrysler Corp.