1999 DODGE RAM instrument cluster

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.

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.

BO DY C O NTR O L C O M PU TE R

1999 D odge P ic ku p R 1500
1999 ACCESSORIES & EQUIPMENT
CHRY - Body Control Computer Tests
Ram Pickup
NOTE: See BODY CONTROL COMPUTER - INTRODUCTION article before
proceeding with following test. Body control computer in RWD
trucks is the Central Timer Module (CTM).
SYMPTOM IDENTIFICATION
IDENTIFYING VEHICLE EQUIPMENT & SYSTEM PROBLEMS
NOTE: For connector terminal identification wiring diagrams, see
BODY CONTROL COMPUTER - INTRODUCTION article.
NOTE: Perform a visual inspection before proceeding with this test.
Ensure battery is fully charged.
1) Connect scan tool to Data Link Connector (DLC). DLC is a
16-pin connector located under left side of dash, to left of steering
wheel. Turn ignition switch to ON position. If scan tool display is
not blank, go to next step. If scan tool display is blank, see
appropriate VEHICLE COMMUNICATIONS article.
2) Using scan tool, select SYSTEM MONITORS, then CCD BUS
TEST. Scan tool will perform a CCD bus test. If scan tool displays BUS
OPERATIONAL, go to next step. If scan tool displays any message except
BUS OPERATIONAL, see appropriate VEHICLE COMMUNICATIONS article.
3) Using scan tool, select READ DTCs. If any Diagnostic
Trouble Codes (fault messages) are present, go to appropriate fault
message. If no fault messages are present, identify customer
complaint. See following list for possible fault messages and customer
complaint symptoms. Problems listed are diagnosed using a scan tool.
These problems may occur separately or in various combinations. When
diagnosing a system with many apparent problems, a sequence of tests
may be required. After repairs, ensure problem(s) or failure(s) have\
been corrected.
CHIME SYSTEM
* CHIME INOPERATIVE - ENGINE TEMPERATURE CRITICAL
* CHIME INOPERATIVE - KEY IN IGNITION & LF DOOR OPEN
* CHIME INOPERATIVE AT ALL TIMES
* CHIME INOPERATIVE WITH EXTERIOR LIGHTS ON
* CHIME INOPERATIVE WITH LOW OIL PRESSURE
* CHIME INOPERATIVE WITH DRIVER DOOR OPEN
DOOR AJAR SYSTEM
* OPEN LEFT DOOR AJAR CIRCUIT
* OPEN RIGHT DOOR AJAR CIRCUIT
* SHORTED LEFT DOOR AJAR CIRCUIT
* SHORTED RIGHT DOOR AJAR CIRCUIT
INSTRUMENT CLUSTER
* ALL GAUGES INOPERATIVE
* ANY CCD CLUSTER WARNING LIGHT INOPERATIVE
* ANY HARD WIRED CLUSTER WARNING LIGHT INOPERATIVE

* ONE GAUGE NOT OPERATING PROPERLY
OVERHEAD CONSOLE CONCERNS
* AVERAGE MPH/FUEL ECON INOPERATIVE OR WRONG (CMTC FAILS TO
RESPOND TO INSTRUMENT CLUSTER DIMMING, DISTANCE TO EMPTY
INOPERATIVE OR WRONG, ELAPSED TIME INOPERATIVE/WRONG, SWITCH
ON CMTC INOPERATIVE, TRIP ODOMETER INOPERATIVE/WRONG)
* CMTC DISPLAY SHOWS FAILED
* CMTC SEGMENTS FAIL TO LIGHT UP
* INCORRECT READING BEYOND +/- 5
* REPAIRING "OC" IN CMTC DISPLAY
* REPAIRING "SC" IN CMTC DISPLAY
POWER DOOR LOCK SYSTEM
* DOOR LOCK SWITCH FAILURE (PDL)
* DOOR UNLOCK SWITCH FAILURE (PDL)
* AUTOMATIC (ROLLING) DOOR LOCKS INOPERATIVE
* DOORS LOCK WITH KEY IN IGNITION & LEFT DOOR OPEN
* ONE OR ALL DOORS FAILING TO LOCK FROM ONE SWITCH (ONE OR ALL
DOORS FAILING TO UNLOCK FROM ONE SWITCH)
* REMOTE KEYLESS ENTRY PROBLEM
VEHICLE THEFT/SECURITY SYSTEM
* DOOR DISARM SWITCH FAILURE
* DOOR LOCK SWITCH FAILURE
* DOOR UNLOCK SWITCH FAILURE
* EEPROM CHECKSUM FAILURE
* INTERNAL ROM TEST FAILURE
* IDENTIFYING VTSS PROBLEMS
WINDSHIELD WIPER SYSTEM
* WIPER PARK SWITCH FAILURE
* INTERMITTENT WIPERS INOPERATIVE
* NO WIPER ACTUATION AFTER WASH BUTTON PUSHED
* WIPER SPEED SENSITIVE FEATURE INOPERATIVE
CHIME SYSTEM
CHIME INOPERATIVE WITH EXTREME COOLANT TEMPERATURE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Using scan tool, actuate chime. If chime sounds, go to
next step. If chime does not sound, replace Central Timer Module
(CTM). CTM is located under left side of instrument panel.
2) Using scan tool, read Powertrain Control Module (PCM)
DTCs. If no engine coolant temperature related codes exist, go to next
step. If engine coolant temperature related codes exist, see
appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE section.
3) Due to difficult access of coolant temperature sensor, Oil
Pressure Switch (OPS) will be used to verify CCD bus message from PCM.\
Disconnect OPS connector. OPS is located near bottom of distributor.

Connect a jumper wire between OPS connector terminals. Start engine
and allow to idle for 20 seconds. Increase engine speed to 1600 RPM.
If chime sounds, system is currently functioning properly. If chime
does not sound, go to next step.
4) Remove instrument cluster. See appropriate INSTRUMENT
PANELS article. Disconnect Instrument cluster 10-pin Gray connector
"B". Connect a jumper wire between ground and Dark Blue/Red wire of
instrument cluster 10-pin Gray connector terminal No. 7. Turn ignition
on. If chime sounds, replace instrument cluster. If chime does not
sound, repair open Dark Blue/Red wire.
CHIME INOPERATIVE - KEY IN IGNITION & LF DOOR OPEN
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Turn ignition off. Open driver's door. If chime does not
sound, go to next step. If chime sounds, system is currently
functioning correctly.
2) Using scan tool, read driver's door ajar switch status. If
scan tool displays LFDOOR AJAR SWITCH: CLOSED, go to next step. If
scan tool does not display LFDOOR AJAR SWITCH: CLOSED, go to OPEN LEFT
DOOR AJAR CIRCUIT.
3) Using scan tool, read key-in ignition chime state. If scan
tool does not display KEY-IN IGNITION CHIME STATE: ON, go to next
step. If scan tool displays KEY-IN IGNITION CHIME STATE: ON, replace
Central Timer Module (CTM). CTM is located under left side of
instrument panel.
4) Disconnect key-in ignition switch connector. See Fig. 1.
Connect jumper wire between key-in ignition switch connector Light
Blue wire and ground. Using scan tool, read key-in ignition chime
state. If scan tool does not display KEY-IN IGNITION CHIME STATE: ON,
go to next step. If scan tool displays KEY-IN IGNITION CHIME STATE:
ON, replace ignition switch. See appropriate STEERING COLUMN SWITCHES
article.
Fig. 1: Identifying Steering Column Harness Connector Locations
Courtesy of Chrysler Corp.
5) Access CTM 14-pin Green connector C1. Remove connector
cover. Do not disconnect connector. Connect a backprobe jumper wire

disconnecting any module connector.
1) Disconnect Oil Pressure Switch (OPS). OPS is located near\
bottom of distributor. Connect a jumper wire between OPS connector
terminals. Start engine and allow to idle for 20 seconds. Increase
engine speed to 1600 RPM. If chime sounds, go to next step. If chime
does not sound, go to step 3).
2) Turn ignition on. Using scan tool, actuate chime. If chime
does not sound, replace Central Timer Module (CTM). CTM is located
under left side of instrument panel. If chime sounds, system is
currently functioning properly.
3) Using scan tool, access CLUSTER MONITOR. With engine
running, read CCD oil pressure. If scan tool reading does not match
instrument cluster reading, replace instrument cluster. If scan tool
reading matches instrument cluster reading, go to next step.
4) Remove jumper wire. Connect a jumper wire between ground
and OPS connector Gray wire. Start engine and allow to idle for 20
seconds. Increase engine speed to 1600 RPM. If chime sounds, repair
open ground circuit between OPS connector and ground. If chime does
not sound, go to next step.
5) Turn ignition on. Using scan tool, actuate chime. If chime
does not sound, replace Central Timer Module (CTM). CTM is located
under left side of instrument panel. If chime sounds, go to next step.
6) Remove instrument cluster. See appropriate INSTRUMENT
PANELS article. Disconnect CTM 14-pin Green connector C1. Using an
external ohmmeter, measure resistance of Dark Blue/Red wire between
CTM 14-pin Green connector C1 terminal No. 2 and instrument cluster
10-pin connector C2 terminal No. 7. If resistance is less than 5 ohms,
replace CTM. If resistance is 5 ohms or more, repair open Dark
Blue/Red wire.
CHIME SOUNDS WITH DRIVER DOOR OPEN
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Ensure all interior and exterior lights are off. Remove
ignition key and open driver's door. If chime does not sound, system
is currently functioning correctly. If chime sounds, go to next step.
2) Using scan tool, read key-in ignition chime state. If scan
tool displays KEY-IN IGNITION CHIME STATE: "ON/OFF", go to next step.
If scan tool does not display KEY-IN IGNITION CHIME STATE: "ON/OFF",
replace Central Timer Module (CTM). CTM is located under left side of
instrument panel.
3) Disconnect key-in ignition switch connector. See Fig. 1.
Using scan tool, read key-in ignition chime state. If scan tool
displays KEY-IN IGNITION CHIME STATE: ON, go to next step. If scan
tool does not display KEY-IN IGNITION CHIME STATE: ON, replace
ignition switch. See appropriate STEERING COLUMN SWITCHES article.
4) Turn ignition off. Disconnect Central Timer Module (CTM).\
CTM is located under left side of instrument panel. Remove ignition
key. Ensure all lights and accessories are off. Close all doors. Using
external ohmmeter, measure resistance between ground and terminal No.
9 (Light Blue wire) on CTM Green connector "A". If resistance is less
than 10 ohms, repair Light Blue wire between CTM and ignition switch
for short to ground. If resistance is 10 ohms or more, replace CTM.
DOOR AJAR SYSTEM

NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Remove driver's door panel. Disconnect driver's door ajar
switch. Using scan tool, read left front door ajar switch status. If
scan tool displays DRDOOR AJAR SW: CLOSED, go to next step. If scan
tool does not display DRDOOR AJAR SW: CLOSED, replace left front door
ajar switch.
2) Disconnect Central Timer Module (CTM) 14-pin Green
connector C1. CTM is located under left side of instrument panel.
Using an external ohmmeter, measure resistance between ground and CTM
14-pin Green connector C1 terminal No. 1 (Tan wire). If resistance is
less than 5 ohms, repair short to ground in Tan wire between CTM 14-
pin connector C1 and left front door ajar switch. If resistance is 5
ohms or more, replace CTM.
SHORTED RIGHT DOOR AJAR CIRCUIT
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Ensure all doors are closed. Open right front door and
remove door panel. Disconnect right front door ajar switch. Using scan
tool, read right front door ajar switch status. If scan tool displays
PASSDOOR AJAR SW: CLOSED, go to next step. If scan tool does not
display PASSDOOR AJAR SW: CLOSED, replace right front door ajar
switch.
2) Disconnect Central Timer Module (CTM) 14-pin Green
connector C1. CTM is located under left side of instrument panel.
Using an external ohmmeter, measure resistance between ground and CTM
14-pin Green connector C1 terminal No. 5 (Black/Light Blue wire). If
resistance is less than 5 ohms, repair short to ground in Black/Light
Blue wire. If resistance is 5 ohms or more, replace CTM.
INSTRUMENT CLUSTER
ALL GAUGES DO NOT OPERATE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Turn ignition on. Using scan tool, select ELECTRO/MECH
CLUSTER. If scan tool displays BUS OPERATIONAL, go to next step. If
scan tool does not display BUS OPERATIONAL, go to appropriate VEHICLE
COMMUNICATIONS article and follow appropriate symptom diagnostics.
2) If scan tool displays NO RESPONSE, go to appropriate
VEHICLE COMMUNICATIONS article. If scan tool does not display NO
RESPONSE, go to next step.
3) Using scan tool, select SYSTEM TEST. If scan tool displays

PCM INACTIVE ON BUS, go to appropriate VEHICLE COMMUNICATIONS article.
If scan tool does not display PCM INACTIVE ON BUS, go to next step.
4) Turn ignition off. Remove instrument cluster. See
appropriate INSTRUMENT PANELS article. Turn ignition on. Using
external voltmeter, measure voltage between ground and instrument
cluster connector C1 terminal No. 6 (Yellow wire). If voltage is 10
volts or less, repair open Yellow wire. If voltage is more than 10
volts, replace instrument cluster.
ANY CCD CLUSTER LIGHT INOPERATIVE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Turn ignition on. Using scan tool, select ELECTRO/MECH
CLUSTER. If scan tool displays BUS OPERATIONAL, go to next step. If
scan tool does not display BUS OPERATIONAL, go to appropriate VEHICLE
COMMUNICATIONS article and follow appropriate symptom diagnostics.
2) If scan tool displays NO RESPONSE, go to appropriate
VEHICLE COMMUNICATIONS article. If scan tool does not display NO
RESPONSE, go to next step.
3) Using scan tool, select SYSTEM TEST. If scan tool displays
PCM INACTIVE ON BUS, go to appropriate VEHICLE COMMUNICATIONS article.
If scan tool does not display PCM INACTIVE ON BUS, go to next step.
4) Push and hold RESET button while cycling ignition key.
Release RESET button when CHEC appears in odometer display. Observe
inoperative light during self-test. If inoperative light did not
illuminate during self-test, go to next step. If inoperative light
illuminated during self-test, verify if light is controlled by an
input to instrument cluster. See appropriate wiring diagram in BODY
CONTROL COMPUTER - INTRODUCTION article. If light is controlled by an
input to instrument cluster, go to appropriate circuits article or
symptom test. See IDENTIFYING VEHICLE EQUIPMENT & SYSTEM PROBLEMS. If
light is not controlled by an input to instrument cluster, system is
currently functioning correctly.
5) Gain access to instrument cluster. See appropriate
INSTRUMENT PANELS article. If defective light is a LED, replace
instrument cluster. If defective light is a bulb, go to next step.
6) Remove and inspect defective bulb. If bulb is burned out,
replace bulb. If bulb is not burned out, replace instrument cluster.
ANY HARD WIRED CLUSTER WARNING LIGHT INOPERATIVE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Remove instrument cluster. See appropriate INSTRUMENT
PANELS article. Remove inoperative bulb. If bulb is burned out,
replace bulb. If bulb is not burned out, go to next step.
2) Inspect wiring diagram and evaluate which instrument
cluster provides; power or ground for inoperative bulb. See
appropriate wiring diagram in BODY CONTROL COMPUTER - INTRODUCTION
article. Using external ohmmeter or voltmeter, check appropriate power
or ground circuit. If circuit is okay, replace instrument cluster. If
power or ground is not available at appropriate circuit, repair open