DODGE RAM 1999 Service Repair Manual

wire) and No. 3 (Black/Yellow wire). If resistance is more than 5 ohm\
s
on either circuit, replace PAD switch. If resistance is less than 5
ohms on either circuit, go to next step.
5) Using an ohmmeter, check resistance between ACM connector
terminal No. 7 (Brown/Yellow wire) and PAD switch 4-pin connector
(harness side) terminal No. 4 (Dark Green/Yellow wire). If resistanc\
e
is more than 5 ohms, repair open or high resistance in Brown/Yellow
wire. If resistance is less than 5 ohms, go to next step.
6) Using an ohmmeter, check resistance between ACM connector
terminal No. 8 (Violet/Yellow wire) and PAD switch 4-pin connector
(harness side) terminal No. 3 (Black/Yellow wire). If resistance is
more than 5 ohms, repair open or high resistance in Violet/Yellow
wire. If resistance is less than 5 ohms, go to next step.
7) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
PASSENGER SQUIB CIRCUIT SHORTED
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. 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. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Turn ignition off. Turn PAD switch to the ON position.
Turn ignition on (engine off). Using DRB, read active codes. If DRB
displays PASSENGER SIDE SQUIB SHORTED DTC, go to next step. If DRB
does not display PASSENGER SIDE SQUIB SHORTED DTC, go to appropriate
diagnostic test.
2) Turn ignition off. Disconnect battery and wait 2 minutes
before proceeding. Disconnect passenger-side air bag module connector.
Disconnect clockspring connector. Go to next step.
3) Using an ohmmeter, check resistance between Passenger-side
air bag 2-pin connector terminal "B" (Dark Green/Yellow wire) and
clockspring 2-pin connector terminal No. 1 (Black/Light Blue wire). If\
resistance is less than 5 ohms, repair short between Dark Green/Yellow
wire and Black/Light Blue wire. If resistance is more than 5 ohms, go
to next step.
4) Using an ohmmeter, check resistance between passenger-side
air bag module 2-pin connector terminal "A" (Black/Yellow wire) and
clockspring 2-pin connector terminal No. 2 (Dark Green/Light Blue
wire). If resistance is less than 5 ohms, repair short between
Black/Yellow wire and Dark Green/Light Blue wire. If resistance is
more than 5 ohms, go to next step.
5) Using an ohmmeter, check resistance between passenger-side
air bag clockspring 2-pin connector terminals. If resistance is less
than 5 ohms, go to next step. If resistance is more than 5 ohms,
replace passenger-side air bag module.
6) Disconnect PAD switch 4-pin connector. Using an ohmmeter,
check resistance between passenger-side air bag module 4-pin connector
(harness side) terminals "A" (Black/Yellow wire) and "B" (Dark
Green/Yellow wire). If resistance is less than 5 ohms, repair short
between Dark Green/Yellow wire Black/Yellow wire. If resistance is
more than 5 ohms, go to next step.
7) Using an ohmmeter, check resistance between PAD switch 4-
pin connector (harness side) terminals No. 1 (Brown/Yellow wire) and\
No. 2 (Violet/Yellow wire). If resistance is less than 5 ohms in
either circuit, repair short between Brown/Yellow wire and
Violet/Yellow wire. If resistance is more than 5 ohms, go to next
step.
8) If there are no potential causes for this DTC remaining,

ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
PASSENGER SQUIB CIRCUIT SHORTED TO GROUND
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. 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. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Disconnect battery and wait 2 minutes before proceeding.
Turn PAD switch to the ON position. Using DRB, read active codes. If
DRB displays PASSENGER SIDE SQUIB SHORTED TO GROUND, go to next step.
If DRB does not display PASSENGER SIDE SQUIB SHORTED TO GROUND,
replace PAD switch.
2) Disconnect passenger-side air bag module connector. Using
an ohmmeter, check resistance between ground and passenger-side air
bag module 2-pin connector terminals "A" (Black/Yellow wire) and "B"
(Dark Green/Yellow wire). If resistance is less than 5 ohms, go to
next step. If resistance is more than 5 ohms, replace passenger-side
air bag module.
3) Disconnect ACM 23-pin connector. Using an ohmmeter, check
resistance between ground and passenger-side air bag module 2-pin
connector terminals "A" (Black/Yellow wire) and "B" (Dark Green/Yello\
w
wire). If resistance is less than 5 ohms in either circuit, go to next
step. If resistance is more than 5 ohms, replace ACM.
4) Disconnect PAD switch 4-pin connector. Using an ohmmeter,
check resistance between ground and passenger-side air bag module 2-
pin connector terminals "A" (Black/Yellow wire) and "B" (Dark
Green/Yellow wire). If resistance is less than 5 ohms in either
circuit, repair short in Black/Yellow wire or Dark Green/Yellow wire.
If resistance is more than 5 volt in either circuit, go to next step.
5) Using an ohmmeter, check resistance between ground and PAD
switch 4-pin connector (harness side) terminals No. 1 (Brown/Yellow
wire) and No. 2 (Violet/Yellow wire). If resistance is less than 5
ohms on either circuit, repair short in Brown/Yellow wire or
Violet/Yellow wire. If voltage is more than 5 ohms on either circuit,
replace PAD switch.
PASSENGER SQUIB CIRCUIT SHORTED TO BATTERY
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. 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. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Turn ignition off. Turn PAD switch to the ON position.
Turn ignition on (engine off). Using DRB, read active codes. If DRB
displays PASSENGER SIDE SQUIB SHORTED TO BATTERY, go to next step. If
DRB does not display PASSENGER SIDE SQUIB SHORTED TO BATTERY, go to
appropriate diagnostic test.
2) Disconnect battery and wait 2 minutes before proceeding.
Disconnect passenger-side air bag module connector. Turn ignition on.
Reconnect battery. Using DRB, read active codes. If DRB does not
display PASS SQUIB SHORTED TO BATTERY, replace passenger-side air bag
module. If DRB displays PASS SQUIB SHORTED TO BATTERY, go to next
step.
3) Disconnect battery and wait 2 minutes before proceeding.
Disconnect ACM 23-pin connector. Turn ignition on (engine off).

Reconnect battery. Using a voltmeter, check voltage between ground and
passenger-side air bag module 2-pin connector terminals "A" and "B".
If voltage is more than 0.5 volt on either circuit, go to next step.
If voltage is less than 0.5 volt on either circuit, replace ACM.
4) Disconnect PAD switch 4-pin connector. Using a voltmeter,
check voltage between ground and passenger-side air bag module 2-pin
connector terminals "A" (Black/Yellow wire) and "B" (Dark Green/Yello\
w
wire). If voltage is more than 0.5 volt in either circuit, repair
short in Black/Yellow wire or Dark Green/Yellow wire. If voltage is
less than 0.5 volt in either circuit, go to next step.
5) Using a voltmeter, check voltage between ground and PAD
switch 4-pin connector (harness side) terminals No. 1 (Brown/Yellow
wire) and No. 2 (Violet/Yellow wire). If voltage is more than 0.5 vol\
t
on either circuit, repair short in Brown/Yellow wire or Violet/Yellow
wire. If voltage is less than 0.5 volt on either circuit, replace PAD
switch.
REPAIRING SEAT BELT CONTROL TIMER MODULE (SCTM)
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. 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. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Using a voltmeter, backprobe (do not disconnect connector)\
main seat connector terminal No. 10 (Light Green/Black wire) to
ground. See WIRING DIAGRAMS for terminal identification. If voltage is
between 1-3 volts, replace ACM. If voltage is less than one volt,
repair open in Light Green/Black wire. If voltage is between 9-10
volts, perform Seat Belt Control Timer Module (SCTM) diagnostics.
Repair as required. If voltage is not between 9-10 volts, go to next
step.
2) Disconnect SCTM connector. Using a voltmeter, check
voltage between ground and SCTM connector terminal No. 11 (Light
Green/Black wire). If voltage is between 9-10 volts, replace SCTM. If
voltage is not between 9-10 volts, go to next step.
3) Turn ignition off. Using an ohmmeter, check resistance
between ground and SCTM connector terminal No. 11 (Light Green/Black
wire). If resistance is less than 5 ohms, repair short in Light
Green/Black wire. If resistance is more than 5 ohms, go to next step.
4) Using an ohmmeter, check resistance between ground and
SCTM connector terminals No. 6 (Black/Light Green wire) and No. 13
(Black/Pink wire). If resistance is more than 5 ohms on either
circuit, repair open in Black/Light Green wire or Black/Pink wire. If
resistance is less than 5 ohms on either circuit, go to next step.
5) Turn ignition off. Using a voltmeter, check voltage
between ground and SCTM connector terminal No. 4 (Dark Blue wire). If
voltage is less than 10 volts, repair open in Dark Blue wire. If
voltage is more than 10 volts, go to next step.
6) Using a voltmeter, check voltage between ground and SCTM
connector terminal No. 5 (Pink wire). If voltage is less than 10
volts, repair open in Pink wire. If voltage is more than 10 volts,
replace SCTM.
REPAIRING SCTM MESSAGE MISMATCH
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. 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. Due to manufacturer changes in wire

colors, use terminal identification whenever possible.
1) If seat belt light is on, go to step 4). If seat belt
light is not on, go to next step.
2) Using DRB, select PASSIVE RESTRAINTS, AIRBAG AND MONITOR
DISPLAY. Read WARNING LAMP STATUS. If DRB does not display MIC S/B
LAMP STATE: OFF, replace instrument cluster. If DRB displays MIC S/B
LAMP STATE: OFF, go to next step.
3) If DRB displays ACM S/B LAMP REQUEST: OFF, replace ACM. If
DRB does not display ACM S/B LAMP REQUEST: OFF, replace instrument
cluster.
4) Using DRB, select PASSIVE RESTRAINTS, AIRBAG AND MONITOR
DISPLAY. Read WARNING LAMP STATUS. If DRB does not display MIC S/B
LAMP STATE: ON, replace instrument cluster. If DRB displays MIC S/B
LAMP STATE: ON, go to next step.
5) Using DRB, read WARNING LAMP STATUS. If DRB does not
display ACM S/B LAMP REQUEST: ON, replace instrument cluster. If DRB
displays ACM S/B LAMP REQUEST: ON, replace ACM.
REPAIRING VIN MESSAGE MISMATCH
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. 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. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Using DRB, select ENGINE (PCM). If DRB displays NO
RESPONSE FROM PCM, perform REPAIRING SHORT TO BATTERY under VEHICLE
COMMUNICATIONS. If DRB does not display NO RESPONSE FROM PCM, and
vehicle is a Club Cab (BE), go to next step. If DRB does not display
NO RESPONSE FROM PCM, and vehicle is a Standard Cab (BR), go to step
3).
2) Using DRB, select PASSIVE RESTRAINTS, AIRBAG AND MONITOR
DISPLAY. Select VIN type to identify 7th digit of VIN (VIN 2 or 3 is
for Club Cab; VIN B is for a Standard Cab). If DRB does not display
PCM VIN: BE, replace powertrain control module. If DRB displays PCM
VIN: BE, replace ACM.
3) Using DRB, select PASSIVE RESTRAINTS, AIRBAG AND MONITOR
DISPLAY. Select VIN type to identify 7th digit of VIN (VIN B is for a
Standard Cab). If DRB does not display PCM VIN: BE, replace powertrain
control module. If DRB displays PCM VIN: BE, replace ACM.
WARNING LAMP CIRCUIT OPEN/SHORTED
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. 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. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Using DRB, select MECHANICAL INSTRUMENT CLUSTER (MIC). If\
DRB displays NO RESPONSE FROM MIC, go to
NO RESPONSE FROM INSTRUMENT CLUSTER under VEHICLE COMMUNICATIONS. If
DRB does not display NO RESPONSE FROM MIC, go to next step.
2) Using DRB, select PASSIVE RESTRAINTS AIRBAG AND MONITOR
DISPLAY. Read WARNING LAMP status. If DRB does not display MIC BULB
STATE, replace instrument cluster. If DRB displays MIC BULB STATE, go
to next step.
3) If DRB does not display MIC DRIVER STATE OK, replace
instrument cluster. If DRB displays MIC DRIVER STATE OK, go to next

step.
4) Observe AIR BAG warning light. Turn ignition off and wait
5 minutes. After 5 minutes, turn ignition on (engine off). If AIR BAG
warning light comes on for 6 to 8 seconds, replace ACM. If AIR BAG
warning light does not come on for 6 to 8 seconds, replace instrument
cluster.
REPAIRING PAD SWITCH
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. 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. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Using DRB, read active DTCs. If DRB displays LOSS OF
IGNITION RUN/START, go to LOSS OF IGNITION RUN/START. If DRB does not
display LOSS OF IGNITION RUN/START, go to next step.
2) Disconnect PAD switch 2-pin connector. Using a voltmeter,
check voltage between PAD switch 2-pin connector terminals No. 1
(Light Green/Yellow wire) and No. 2 (Black wire). If voltage is less\
than 10 volts, repair open in Light Green/Yellow wire. If voltage is
more than 10 volts, go to next step.
3) Turn ignition off. Using an ohmmeter, check resistance
between ground and PAD switch connector terminal No. 2 (Black wire).
If resistance is more than 5 ohms, repair open in Black wire. If
resistance is less than 5 ohms, replace PAD switch.
PAD SWITCH INDICATOR PROBLEMS
1) If PAD switch off indicator fails to illuminate in OFF
position, go to next step. If PAD switch off indicator does not fail
to illuminate in OFF position, go to step 5).
2) Using DRB, read active DTCs. If DRB displays LOSS OF
IGNITION RUN/START, go to diagnostic test for that DTC. If DRB does
not display LOSS OF IGNITION RUN/START, go to next step.
3) Disconnect PAD switch 2-pin connector. Turn ignition on.
Measure voltage between ground and PAD switch 2-pin connector Light
Green/Yellow wire. If voltage is more than 10 volts, go to next step.
If voltage is less than 10 volts, repair open in Light Green/Yellow
wire.
4) Turn ignition off. Measure resistance between ground and
PAD switch 2-pin connector Black/Pink wire. If resistance is less than
5 ohms, replace PAD switch. If resistance is more than 5 ohms, repair
open in Black/Pink wire.
5) Ensure battery is fully charged. Using DRB, read and
record both active and stored code(s). Erase stored codes. Check for
active DTC(s) in either PAD switch position. If PAD switch off
indicator illuminates in ON position, replace PAD switch. If PAD
switch off indicator does not illuminate in ON position, test
complete.
AIR BAG VERIFICATION TEST
1) Remove all jumper wires. Reconnect all previously
disconnected components (except battery). Turn ignition on and
reconnect battery. Connect DRB to data link connector. Using DRB,
erase stored codes.
2) Turn ignition off and wait 15 seconds before turning
ignition on. Wait one minute. Read active codes. If DRB displays any
active codes, perform appropriate diagnostic test. If DRB does not
display any active codes, go to next step.

3) Using DRB, read stored codes. If DRB displays stored
codes, perform appropriate diagnostic test. If DRB does not display
any stored codes, system is operating properly at this time.
COMPONENT VERIFICATION TEST
Reconnect all previously disconnected components and
connectors. Turn ignition on (engine off). Fully operate system that
was malfunctioning. If system operates properly, repair is complete.
If system does not operate properly, go to appropriate diagnostic
test.
VEHICLE COMMUNICATIONS
VEHICLE COMMUNICATION PROBLEMS
NOTE: Use this test only when instructed to do so by another
diagnostic test. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
DRB Blank Screen
If DRB Screen is blank, disconnect DRB from data link
connector. Ensure good ground exists at data link connector terminal
No. 4 (Black/Tan wire). Ensure 12-volts exists at data link connector
terminal No. 16 (Pink wire). If 12-volts does not exist, check for
blown fuse No. 12 located in power distribution center. If no problems
can be found, try a different DRB cable and/or a different DRB.
No Response Condition
If no response condition from Air Bag Control Module (ACM)
exists, go to NO RESPONSE FROM AIR BAG CONTROL MODULE .
NO RESPONSE FROM AIR BAG CONTROL MODULE
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. 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. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Remove and inspect fuse No. 19. If fuse is blown, go to
OPEN FUSED IGNITION SWITCH OUTPUT (RUN/START) CKT . If not, go to next
step.
2) Using a voltmeter, measure ignition switch output
RUN/START at fuse No. 19. See WIRING DIAGRAMS. If voltage is more than
10 volts, go to next step. If voltage is less than 10 volts, repair
open ignition switch output RUN/START circuit.
3) Turn ignition off and wait 2 minutes. Disconnect ACM
connector. Reinstall fuse No. 19. Turn ignition on (engine off). Using\
a voltmeter, check voltage at ACM connector terminal No. 14 (Light
Green/Yellow wire). If voltage is more than 10 volts, go to next step.
If voltage is less than 10 volts, repair open in Light Green/Yellow
wire.
4) Turn ignition off. Using DRB in ohmmeter mode, check
resistance at ACM connector terminal No. 4 (Black/Pink wire). If
resistance is more than 5 ohms, repair open in Black/Pink wire. If
resistance is less than 5 ohms, go to next step.
5) Turn ignition on (engine off). Using DRB in voltmeter
mode, check voltage at ACM connector terminal No. 21 (Violet/Brown
wire). If voltage is 1.8-2.6 volts, go to next step. If voltage is not
1.8-2.6 volts, repair open in Violet/Brown wire.

6) Using DRB in voltmeter mode, check voltage at ACM
connector terminal No. 22 (White/Black wire). If voltage is 1.8-2.6
volts, replace ACM. If voltage is not 1.8-2.6 volts, repair open in
White/Black wire.
OPEN FUSED IGNITION SWITCH OUTPUT (RUN/START) CKT
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. 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. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Turn ignition on (engine off). Using DRB in voltmeter
mode, probe output side (Dark Blue wire) of fuse No. 19 located in
junction block. If voltage is less than 10 volts, repair open in Dark
Blue wire. If voltage is more than 10 volts, go to next step.
2) Turn ignition off and wait 2 minutes before proceeding.
Using DRB in ohmmeter mode, probe fused side (Light Green/Yellow wire)\
of fuse No. 19 located in junction block. If resistance is less than 5
ohms, go to next step. If resistance is more than 5 ohms, go to step
4).
3) Disconnect ACM connector. Using DRB in ohmmeter mode,
probe fused side (Light Green/Yellow wire) of fuse No. 19 located in
junction block. If resistance is less than 5 ohms, repair short to
ground in Light Green/Yellow wire an replace fuse No. 19. If
resistance is more than 5 ohms, replace ACM and fuse No. 19.
4) Turn ignition off and wait 2 minutes before proceeding.
Disconnect ACM. Using an ohmmeter, check resistance between ACM
connector terminal No. 14 (Light Green/Yellow wire) and fused side
(Light Green/Yellow wire) of fuse No. 19 located in junction block. If\
resistance is more than 5 ohms, repair open in Light Green/Yellow wire
and replace fuse No. 19. If resistance is less than 5 ohms, go to next
step.
5) Reconnect ACM connector. Turn ignition on (engine off).
replace fuse No. 19. Perform appropriate diagnostic test under
DIAGNOSTIC TESTS.
NO RESPONSE FROM POWERTRAIN CONTROL MODULE
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. 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. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) If engine does not run, repair as required. If engine
runs, disconnect Powertrain Control Module (PCM) connectors. Connect a\
jumper wire between ground and PCM Gray connector terminal C30
(Violet/Brown wire). Using DRB, perform CCD bus test. If DRB does not
display SHORT TO GROUND, repair open Violet/Brown wire. If DRB
displays SHORT TO GROUND, go to next step.
2) Connect a jumper wire between ground and PCM Gray
connector terminal C28 (White/Black wire). Using DRB, perform CCD bus
test. If DRB does not display SHORT TO GROUND, repair open White/Black
wire. If DRB displays SHORT TO GROUND, replace PCM.
REPAIRING SHORT TO BATTERY
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. 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. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Ensure ignition switch is in the RUN position. Disconnect
Powertrain Control Module (PCM) connectors. If DRB does not display
BUS SHORT TO BATTERY, to step 8). If DRB displays BUS SHORT TO
BATTERY, go to next step.
2) Disconnect instrument cluster connectors. If DRB does not
display BUS SHORT TO BATTERY, replace instrument cluster. If DRB
displays BUS SHORT TO BATTERY, go to next step.
3) Turn ignition off and wait 2 minutes before proceeding.
Disconnect air bag control module connector. Turn ignition on (engine
off). If DRB does not display SHORT TO BATTERY, replace ACM. If DRB
displays SHORT TO BATTERY, go to next step.
4) Disconnect Central Timer Module (CTM) 18-pin connector. I\
f
DRB does not display BUS SHORT TO BATTERY, replace CTM. If DRB
displays BUS SHORT TO BATTERY, go to next step.
5) Disconnect anti-lock brake controller. If DRB does not
display BUS SHORT TO BATTERY, replace anti-lock brake controller. If
DRB displays BUS SHORT TO BATTERY, go to next step.
6) Disconnect DRB from Data Link Connector (DLC). Using a
voltmeter, check voltage between ground and DLC connector terminal No.
3 (Violet/Brown wire). If voltage is more than 0.2 volt, repair short
in Violet/Brown wire. If voltage is less than 0.2 volt, go to next
step.
7) Using a voltmeter, check voltage between ground and DLC
connector terminal No. 11 (White/Black wire). If voltage is more than
0.2 volt, repair short in White/Black wire. If voltage is less than 0.
2 volt, replace DRB or DRB cable as necessary.
8) Turn ignition off. Using an ohmmeter, check resistance
between ground and PCM Black connector terminal A31 (Black/Tan wire).
If resistance is more than 10 ohms, repair open in Black/Tan wire). If
resistance is less than 10 ohms, go to next step.
9) Using an ohmmeter, check resistance between ground and PCM
Black connector terminal A32 (Black/Tan wire). If resistance is more
than 10 ohms, repair open in Black/Tan wire). If resistance is less
than 10 ohms, replace Powertrain Control Module (PCM).
NO RESPONSE FROM INSTRUMENT CLUSTER
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. 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. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Remove Instrument cluster. Using DRB, turn on INTERNAL BUS
BIAS under SYSTEM MONITORS CCD BUS VOLTAGE. Connect a jumper wire from
Black instrument cluster 10-pin connector "A" terminal No. 9
(White/Black wire) to ground. Observe CCD BUS voltage on DRB. If
voltage did not drop to about zero volt, repair open in White/Black
wire. If voltage drops to about zero volt, go to next step.
2) Leave internal DRB CCD BUS BIAS turned on. Connect a
jumper wire from ground to Black instrument cluster 10-pin connector
"A" terminal No. 10 (Violet/Brown wire). Go to next step.
3) Observe CCD BUS voltage on DRB. If voltage did not drop to
about zero volt, repair open in Violet/Brown wire. If voltage drops to
about zero volt, replace instrument cluster.

WIRING DIAGRAMS
Fig. 20: Air Bag System Wiring Diagram

AN TI- L O CK B RAK E S A FE TY P R EC AU TIO NS

1999 D odge P ic ku p R 1500
GENERAL INFORMATION
Anti-Lock Brake Safety Precautions
* PLEASE READ THIS FIRST *
This article is intended for general information purposes
only. This information may not apply to all makes and models. If
vehicle is equipped with Anti-Lock Brake System (ABS), refer to
appropriate ANTI-LOCK BRAKE SYSTEM article in the BRAKES section for
description, operation, depressurizing, testing, system bleeding,
trouble shooting and servicing of specific system.
WARNING: Failure to depressurize ABS could lead to physical injury.
ANTI-LOCK BRAKE SAFETY PRECAUTIONS
WARNING: Failure to depressurize ABS could lead to physical injury.
* NEVER open a bleeder valve or loosen a hydraulic line
while ABS is pressurized.
* NEVER disconnect or reconnect any electrical connectors
while ignition is on. Damage to ABS control unit may result.
* DO NOT attempt to bleed hyudarulic system without first
referring to the appropriate ANTI-LOCK BRAKE SYSTEM article
in the BRAKES section.
* Only use specially designed brake hoses/lines on ABS equipped
vehicles.
* DO NOT tap on speed sensor components (sensor, sensor rings).
Sensor rings must be pressed into hubs, NOT hammered into
hubs. Striking these components can cause demagnetization or
a loss of polarization, affecting the accuracy of the speed
signal returning to the ABS control unit.
* DO NOT mix tire sizes. Increasing the width, as long as tires
remain close to the original diameter, is acceptable. Rolling
diameter must be identical for all 4 tires. Some
manufacturers recommend tires of the same brand, style and
type. Failure to follow this precaution may cause inaccurate
wheel speed readings.
* DO NOT contaminate speed sensor components with grease. Only
use recommended coating, when system calls for an
anti-corrosion coating.
* When speed sensor components have been removed, ALWAYS check
sensor-to-ring air gaps when applicable. These specifications
can be found in each appropriate article.
* ONLY use rocommended brake fluids. DO NOT use silicone brake
fluids in an ABS equipped vehicle.
* When instlling transmittion devices (CB's, telephones, etc.)
on ABS equipped vehicles, DO NOT locate the antenna near the
ABS control unit (or any control unit).
* Disconnect all on-board computers, when using electric
welding equipment.
* DO NOT expose the ABS control unit to prolonged periods of
high heat (185
F/85C for 2 hours is generally considered a
maximum limit).