DLC DODGE RAM 1999 Service Service Manual

resistance between ground and instrument cluster connector C1 terminal
No. 10 (Violet/Brown wire). If resistance is less than 5 ohms, replace\
instrument cluster. If resistance is 5 ohms or more, repair open
Violet/Brown wire.
BUS (+) & BUS (-) SHORTED TOGETHER
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1 after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module
connector.
1) Turn ignition off. Disconnect Powertrain Control Module
(PCM). PCM is mounted in right side of firewall. Turn ignition on. If
scan tool does not display BUS (+) & BUS (-) SHORTED TOGETHER, repla\
ce
PCM. If scan tool displays BUS (+) & BUS (-) SHORTED TOGETHER, go to\
next step.
2) Turn ignition off. Disconnect anti-lock brake controller
module. Controller is mounted to top of ABS hydraulic unit. Turn
ignition on. If scan tool does not display BUS (+) & BUS (-) SHORTED\
TOGETHER, replace anti-lock brake controller module. If scan tool
displays BUS (+) & BUS (-) SHORTED TOGETHER, go to next step.
3) Turn ignition off. Disconnect instrument cluster. Turn
ignition on. If scan tool does not display BUS (+) & BUS (-) SHORTED\
TOGETHER, replace instrument cluster circuit board. If scan tool
displays BUS (+) & BUS (-) SHORTED TOGETHER, go to next step.
4) Turn ignition off. Disconnect compass mini-trip computer.
Turn ignition on. If scan tool does not display BUS (+) & BUS (-)
SHORTED TOGETHER, replace compass mini-trip computer. If scan tool
displays BUS (+) & BUS (-) SHORTED TOGETHER, go to next step.
5) Turn ignition off. Disconnect radio connector. Turn
ignition on. If scan tool does not display BUS (+) & BUS (-) SHORTED\
TOGETHER, replace radio. If scan tool displays BUS (+) & BUS (-)
SHORTED TOGETHER, go to next step.
6) Turn ignition off and wait 2 minutes. Disconnect Air Bag
Control Module (ACM). ACM is located under center of instrument panel.\
Turn ignition on. If scan tool does not display BUS (+) & BUS (-)
SHORTED TOGETHER, replace ACM. If scan tool displays BUS (+) & BUS (-\
)
SHORTED TOGETHER, go to next step.
7) Turn ignition off. Disconnect Central Timer Module (CTM).\
CTM is located under left side of instrument panel. Turn ignition on.
If scan tool does not display BUS (+) & BUS (-) SHORTED TOGETHER,
replace CTM. If scan tool displays BUS (+) & BUS (-) SHORTED TOGETHE\
R,
go to next step.
8) Disconnect scan tool from DLC. Using external ohmmeter,
measure resistance between terminals No. 3 (Violet/Brown wire) and No.\
11 (White/Black wire) on DLC connector. If resistance is less than 5
ohms, repair short between Violet/Brown wire and White/Dark Green
wire. If resistance is 5 ohms or more, replace scan tool cable or scan
tool as necessary.
BUS BIAS LEVEL TOO LOW (BUS BIAS LEVEL TOO HIGH)
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1 after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module
connector.
1) Disconnect scan tool. Using an external voltmeter, measure

voltage between ground and DLC connector terminal No. 3 (Violet/Brown
wire). If voltage is not 1.8-2.8 volts, go to step 9). If voltage is
1.8-2.8 volts, go to next step.
2) Measure voltage between ground and DLC connector terminal
No. 11 (White/Black wire). If voltage is not 1.8-2.8 volts, go to next\
step. If voltage is 1.8-2.8 volts, replace scan tool cable or scan
tool.
3) Turn ignition off. Disconnect instrument cluster. Ensure
interior lights are off. Using external ohmmeter, measure resistance
between ground and instrument cluster connector C1 terminal No. 10
(Violet/Brown wire). If resistance is less than 1000 ohms, repair
Violet/Brown wire for short to ground. If resistance is 1000 ohms or
more, go to next step.
4) Measure resistance between ground and instrument cluster
connector C1 terminal No. 9 (White/Black wire). If resistance is less
than 1000 ohms, repair White/Black wire for short to ground. If
resistance is 1000 ohms or more, go to next step.
5) Connect jumper wire between ground and DLC connector
terminal No. 3 (White/Black wire). Measure resistance between ground
and instrument cluster connector C1 terminal No. 10 (Violet/Brown
wire). If resistance is less than 5 ohms, go to next step. If
resistance is 5 ohms or more, repair open Violet/Brown wire.
6) Disconnect jumper wire. Connect jumper wire between ground
and DLC connector terminal No. 11 (White/Black wire). Measure
resistance between ground and instrument cluster connector C1 terminal
No. 9 (White/Black wire). If resistance is less than 5 ohms, go to
next step. If resistance is 5 ohms or more, repair open White/Black
wire.
7) Disconnect jumper wire. Measure resistance between ground
and instrument cluster connector C1 terminal No. 4 (Black/Light Green
wire). If resistance is 5 ohms or less, repair open Black/Light Green
wire. If resistance is more than 5 ohms, go to next step.
8) Measure resistance between ground and instrument cluster
connector C1 terminal No. 5 (Black wire). If resistance is 5 ohms or
less, repair open Black wire. If resistance is more than 5 ohms,
replace instrument cluster.
9) Turn ignition off. Disconnect instrument cluster. Ensure
interior lights are off. Measure resistance between ground and
instrument cluster connector C1 terminal No. 4 (Black/Light Green
wire). If resistance is 5 ohms or less, repair open Black/Light Green
wire. If resistance is more than 5 ohms, go to next step.
10) Measure resistance between ground and instrument cluster
connector C1 terminal No. 5 (Black wire). If resistance is 5 ohms or
less, repair open Black wire. If resistance is more than 5 ohms,
replace instrument cluster.
11) Connect jumper wire between ground and DLC connector
terminal No. 11 (White/Black wire). Measure resistance between ground
and instrument cluster connector C1 terminal No. 9 (White/Black wire).\
If resistance is less than 5 ohms, go to next step. If resistance is 5
ohms or more, repair open White/Black wire.
12) Disconnect jumper wire. Measure resistance between ground
and instrument cluster connector C1 terminal No. 9 (White/Black wire).\
If resistance is less than 1000 ohms, repair White/Black wire for
short to ground. If resistance is 1000 ohms or more, go to next step.
13) Connect jumper wire between ground and DLC connector
terminal No. 3 (White/Black wire). Measure resistance between ground
and instrument cluster connector C1 terminal No. 10 (Violet/Brown
wire). If resistance is less than 5 ohms, go to next step. If
resistance is 5 ohms or more, repair open Violet/Brown wire.
14) Using external ohmmeter, measure resistance between
ground and instrument cluster connector C1 terminal No. 10
(Violet/Brown wire). If resistance is less than 1000 ohms, repair
Violet/Brown wire for short to ground. If resistance is 1000 ohms or

more, replace instrument cluster.
NO BUS BIAS
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1 after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module
connector.
1) Disconnect scan tool. Turn ignition on. Using an external
voltmeter, measure voltage between ground and DLC terminal No. 3
(Violet/Brown wire). If voltage is not 1.8-2.3 volts, go to step 3).
If voltage is 1.8-2.3 volts, go to next step.
2) Measure voltage between ground and DLC terminal No. 11
(White/Black wire). If voltage is not 1.8-2.3 volts, go to next step.
If voltage is 1.8-2.3 volts, replace scan tool cable or scan tool.
3) Connect jumper wire between ground and DLC connector
terminal No. 11 (White/Black wire). Turn ignition off. Remove
instrument cluster. Using external ohmmeter, measure resistance
between ground and instrument cluster connector C1 terminal No. 9
(White/Black wire). If resistance is less than 5 ohms, go to next
step. If resistance is 5 ohms or more, repair open White/Black wire.
4) Disconnect jumper wire. Measure resistance between ground
and instrument cluster connector C1 terminal No. 9 (White/Black wire).\
If resistance is less than 1000 ohms, repair White/Black wire for
short to ground. If resistance is 1000 ohms or more, go to next step.
5) Connect jumper wire between ground and DLC connector
terminal No. 3 (White/Black wire). Measure resistance between ground
and instrument cluster connector C1 terminal No. 10 (Violet/Brown
wire). If resistance is less than 5 ohms, go to next step. If
resistance is 5 ohms or more, repair open Violet/Brown wire.
6) Disconnect jumper wire. Measure resistance between ground
and instrument cluster connector C1 terminal No. 10 (Violet/Brown
wire). If resistance is less than 1000 ohms, repair Violet/Brown wire
for short to ground. If resistance is 1000 ohms or more, go to next
step.
7) Turn ignition on. Using external voltmeter, measure
voltage between ground and instrument cluster connector C1 terminal
No. 2 (Dark Blue/White wire). If voltage is 9.5 volts or less, repair
open Dark Blue/White wire. If voltage is more than 9.5 volts, go to
next step.
8) Turn ignition off. Using external ohmmeter, measure
resistance between ground and instrument cluster connector C1 terminal
No. 4 (Black/Light Green wire). If resistance is 5 ohms or less, go to\
next step. If resistance is more than 5 ohms, repair open Black/Light
Green wire.
9) Measure resistance between ground and instrument cluster
connector C1 terminal No. 5 (Black/Orange wire). If resistance is 5
ohms or less, replace instrument cluster. If resistance is more than 5
ohms, repair open Black/Orange wire.
NO RESPONSE AIR BAG CONTROL MODULE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1 after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module
connector.
1) Remove and inspect fuse No. 19 from junction block.

ignition on. If scan tool does not display BUS SHORT TO 5 VOLTS,
replace CTM. If scan tool displays BUS SHORT TO 5 VOLTS, go to next
step.
8) Disconnect scan tool from DLC. Using external voltmeter,
measure voltage between ground and DLC connector terminal No. 3
(Violet/Brown wire). If voltage is more than 4 volts, repair
Violet/Brown wire for short to voltage. If voltage is 4 volts or less,
go to next step.
9) Measure voltage between ground and DLC connector terminal
No. 11 (White/Black wire). If voltage is more than 4 volts, repair
White/Black wire for short to voltage. If voltage is less than 4
volts, replace scan tool cable or scan tool as necessary.
10) Turn ignition off. Using external ohmmeter, measure
resistance between Powertrain Control Module (PCM) connector C3
terminal No. 30 (Violet/Brown wire) and connector C1 terminal No. 17
(Violet/Black wire). PCM is located at right inner fender. If
resistance is less than 800 ohms, repair short between Violet/Brown
wire and Violet/Black wire. If resistance is 800 ohms or more, go to
next step.
11) Measure resistance between PCM connector C3 terminal No.
28 (White/Black wire) and PCM connector C1 terminal No. 17
(Violet/Black wire). If resistance is less than 800 ohms, repair short\
between Violet/Black and White/Black wires of both connectors. See
wiring diagram for clarification. If resistance is 800 ohms or more,
replace PCM.
BUS SHORT TO BATTERY
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1 after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module
connector.
1) Turn ignition off. Disconnect Powertrain Control Module
(PCM). PCM is mounted in right side of firewall. Turn ignition on. If
scan tool does not display BUS SHORT TO BATTERY, go to step 10). If
scan tool displays BUS SHORT TO BATTERY, go to next step.
2) Turn ignition off. Disconnect instrument cluster. Turn
ignition on. If scan tool does not display BUS SHORT TO BATTERY,
replace instrument cluster. If scan tool displays BUS SHORT TO
BATTERY, go to next step.
3) Turn ignition off. Disconnect compass mini-trip computer.
Turn ignition on. If scan tool does not display BUS SHORT TO BATTERY,
replace compass mini-trip computer. If scan tool displays BUS SHORT TO
BATTERY, go to next step.
4) Turn ignition off. Disconnect CCD radio. Turn ignition on.
If scan tool does not display BUS SHORT TO BATTERY, replace radio. If
scan tool displays BUS SHORT TO BATTERY, go to next step.
5) Turn ignition off and wait 2 minutes. Disconnect Air Bag
Control Module (ACM). ACM is located under center of instrument panel.\
Turn ignition on. If scan tool does not display BUS SHORT TO BATTERY,
replace ACM. If scan tool displays BUS SHORT TO BATTERY, go to next
step.
6) Turn ignition off. Disconnect Central Timer Module (CTM).\
CTM is located under left side of instrument panel. Turn ignition on.
If scan tool does not display BUS SHORT TO BATTERY, replace CTM. If
scan tool displays BUS SHORT TO BATTERY, go to next step.
7) Turn ignition off. Disconnect anti-lock brake controller
module. Controller module is mounted to top of ABS hydraulic unit.
Turn ignition on. If scan tool does not display BUS SHORT TO BATTERY,
replace anti-lock brake controller module. If scan tool displays BUS

SHORT TO BATTERY, go to next step.
8) Disconnect scan tool from DLC. Using external voltmeter,
measure voltage between ground and DLC connector terminal No. 3
(Violet/Brown wire). If voltage is more than .2 volt, repair
Violet/Brown wire for short to voltage. If voltage is .2 volt or less,
go to next step.
9) Measure voltage between ground and DLC connector terminal
No. 11 (White/Black wire). If voltage is more than .2 volt, repair
White/Black wire for short to voltage. If voltage is less than .2
volt, replace scan tool cable or scan tool as necessary.
10) Turn ignition off. Using external ohmmeter, measure
resistance between ground and Powertrain Control Module (PCM)
connector C1 terminal No. 31 (Black/Tan wire). PCM is located at right\
inner fender, at corner of firewall. If resistance is less than 10
ohms, go to next step. If resistance is 10 ohms or more, repair open
Black/Tan wire.
11) Measure resistance between ground and PCM connector C1
terminal No. 32 (Black/Tan wire). If resistance is less than 10 ohms,
replace PCM. If resistance is 5 ohms or more, repair open Black/Tan
wire.
BUS SHORT TO GROUND
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1 after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module
connector.
1) Turn ignition off. Disconnect Powertrain Control Module
(PCM). PCM is mounted in right side of firewall. Turn ignition on. If
scan tool does not display BUS SHORT TO GROUND, replace PCM. If scan
tool displays BUS SHORT TO GROUND, go to next step.
2) Turn ignition off. Disconnect anti-lock brake controller
module. Controller module is mounted to top of ABS hydraulic unit.
Turn ignition on. If scan tool does not display BUS SHORT TO GROUND,
replace anti-lock brake controller module. If scan tool displays BUS
SHORT TO GROUND, go to next step.
3) Turn ignition off. Disconnect instrument cluster. Turn
ignition on. If scan tool does not display BUS SHORT TO GROUND,
replace instrument cluster circuit board. If scan tool displays BUS
SHORT TO GROUND, go to next step.
4) Turn ignition off. Disconnect compass mini-trip computer.
Turn ignition on. If scan tool does not display BUS SHORT TO GROUND,
replace compass mini-trip computer. If scan tool displays BUS SHORT TO
GROUND, go to next step.
5) Turn ignition off. Disconnect CCD radio. Turn ignition on.
If scan tool does not display BUS SHORT TO GROUND, replace radio. If
scan tool displays BUS SHORT TO GROUND, go to next step.
6) Turn ignition off and wait 2 minutes. Disconnect Air Bag
Control Module (ACM). ACM is located under center of instrument panel.\
Turn ignition on. If scan tool does not display BUS SHORT TO GROUND,
replace ACM. If scan tool displays BUS SHORT TO GROUND, go to next
step.
7) Turn ignition off. Disconnect Central Timer Module (CTM).\
CTM is located under left side of instrument panel. Turn ignition on.
If scan tool does not display BUS SHORT TO GROUND, replace CTM. If
scan tool displays BUS SHORT TO GROUND, go to next step.
8) Disconnect scan tool from DLC. Using external ohmmeter,
measure resistance between ground and DLC connector terminal No. 3
(Violet/Brown wire). If resistance is less than 700 ohms, repair
Violet/Brown wire for short to ground. If resistance is 700 ohms or

more, go to next step.
9) Measure resistance between ground and DLC connector
terminal No. 11 (White/Black wire). If resistance is less than 700
ohms, repair White/Dark Green wire for short to ground. If resistance
is 700 ohms or more, replace scan tool cable or scan tool as
necessary.
VERIFICATION TEST VER-1
1) Reconnect all previously disconnect connectors. Turn
ignition on, engine off. Using scan tool, erase all fault messages.
Turn ignition off. Wait 10 seconds. Turn ignition on, engine off.
Operate system that is malfunctioning. If system does not operate
properly, perform SYMPTOM IDENTIFICATION of BODY CONTROL COMPUTER
TESTS - RAM PICKUP article. If system operates properly, go to next
step.
2) Using scan tool, read fault messages. If fault messages
exist, perform SYMPTOM IDENTIFICATION of BODY CONTROL COMPUTER TESTS -
RAM PICKUP article. If fault messages do not exist, repair is
complete.