1999 DODGE RAM warning

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.

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).

13) On A/T models, ensure all electrical connectors are clean
and properly connected to electrical plugs on transmission case. On
all models, check for loose or defective electrical connections on
starter and starter solenoid.
MECHANICAL INSPECTION
Compression
Manufacturer does not provide information for checking
compression.
FUEL SYSTEM
AIR IN FUEL SYSTEM
NOTE: Air in the fuel system may cause hard starting, rough
running, excessive smoke, poor engine performance, engine
misfire, poor fuel economy and fuel knock. Air may enter fuel
system whenever fuel supply lines, fuel filter/water
separator, fuel injection pump, fuel injectors or high
-pressure fuel lines are removed or disconnected.
1) Inspect all low-pressure fuel lines from fuel tank to fuel
transfer pump, fuel heater and fuel filter/water separator for signs
of leakage. Inspect all high-pressure fuel lines for signs of leakage.
See FUEL INJECTOR & HIGH-PRESSURE FUEL LINES under FUEL SYSTEM.
2) After repairing fuel leak, bleed air from fuel system. See
FUEL LINE BLEEDING under FUEL SYSTEM in REMOVAL, OVERHAUL &
INSTALLATION - TRUCKS - DIESEL article.
FUEL HEATER
1) Fuel heater is located in fuel filter/water separator. See
Fig. 1 . Fuel heater uses a fuel heater temperature sensor for
controlling operation of the fuel heater.
2) A defective fuel heater may cause excessive wax build-up
in the fuel filter/water separator during cold ambient temperatures.
Wax build-up may cause hard starting, prevent engine from
accelerating, low power, Blue smoke or White smoke. For testing of
fuel heater and fuel heater temperature sensor, see SYSTEM & COMPONENT
TESTING - TRUCKS - DIESEL article.
FUEL HEATER RELAY
Ensure fuel heater relay, located in power distribution
center is installed correctly and that terminals are not corroded. For
fuel heater relay testing, see SYSTEM & COMPONENT TESTING - TRUCKS -
DIESEL article.
FUEL FILTER/WATER SEPARATOR
NOTE: A blocked or restricted fuel filter/water separator may cause
starting problems, prevent engine from accelerating, low
power or White smoke. If an excessive amount of water
collects in filter/separator in a short period of time, it
may be necessary to drain and clean fuel tank.
1) When ignition switch is first turned to ON position,
WATER-IN-FUEL (WIF) warning light should come on for 2 seconds to
perform bulb and wiring circuit test and then go off. WATER-IN-FUEL
(WIF) warning light is located on instrument panel, just below the

tachometer.
2) If WATER-IN-FUEL (WIF) warning light stays on, water
should be drained from fuel filter/water separator. To drain water
from fuel filter/water separator, ensure engine is not running. Place
drain pan below drain tube at fuel filter/water separator. See Fig. 1.
3) Rotate handle on drain valve forward, toward front of
vehicle to OPEN position. Drain valve is located near top of fuel
filter/water separator. See Fig. 1.
4) Allow water to drain until clean flow of diesel fuel
exists. Rotate handle on drain valve back to CLOSE position.
FUEL TRANSFER PUMP
NOTE: A defective fuel transfer pump may cause low power, hard
starting and White smoke. Check fuel transfer pump output
pressure (cranking and starting), pressure drop and fuel
supply.
Fuel Transfer Pump Preliminary Inspection
1) Check for restricted or leaking fuel supply line to fuel
transfer pump or fuel return line located on driver's side of engine.
See Fig. 1 . Repair fuel supply line or fuel return line if restricted
or leaking.
2) Check for fuel leaking from fuel transfer pump. Replace
fuel transfer pump if fuel is leaking. Check fuel transfer pump output
pressure.
Fuel Transfer Pump Output Pressure
1) Clean area around filter fitting plugs, then remove plugs.
See Fig. 7 . Install Test Fittings (AVU1-2). Install Fuel Pressure Test
Gauge (6828) at inlet port. See Fig. 7. To prevent engine starting,
remove fuel injection pump relay, located in power distribution
center.
2) Turn ignition switch to START position. Inlet pressure
should be 5-7 psi. Install fuel injection pump relay. Start engine.
Inlet pressure should be 10 psi. Using a scan tool, clear FTC. FTC may
set when relay is removed. Check pressure drop.
Fig. 7: Checking Fuel Transfer Pump Output Pressure
Courtesy of Chrysler Corp.
Pressure Drop Test
Turn engine off. Move pressure gauge from inlet port to

outlet port. See Fig. 7. Start engine. Outlet pressure should not be
more 5 psi (0.4 kg/cm) less than inlet pressure. If pressure drop is
more than 5 psi (0.4 kg/cm), replace fuel filter and retest pressure.
If pressure drop is less than 5 psi (0.4 kg/cm), check for fuel
supply restriction.
NOTE: Due to very small vacuum specifications, use a scan tool and
Periphal Expansion Port (PEP) module with 0-15 psi transducer\
to perform following test.
Fuel Supply Restriction Test
Ensure transfer pump pressure is okay. Disconnect fuel supply
line at fuel transfer pump inlet. Remove plastic clip from pump inlet
and install in end of fuel supply line. Install 3/8" Adapter Hose
(6631) between fuel supply line and pump inlet. Install transducer
from PEP module to "T" fitting on adapter. Connect scan tool to
module. Start engine. Check vacuum reading with engine at full
throttle with no load. If vacuum reading is less than 6 in. Hg, check
for fuel supply air leaks. If vacuum reading is 6 in. Hg or more,
check fuel line for damage, dents and kinks. Repair as necessary. If
no problem is found, remove fuel module from fuel tank and check for
obstructions. Repair as necessary.
NOTE: A 3' section of 1/4" I.D. clear tubing and a 1/8" NPT fitting
are required for the following test.
Fuel Supply Air Leak Test
Clean area around filter inlet fitting plug, then remove
plug. See Fig. 7. Install 1/8" NPT fitting with 1/4" nipple fitting in
test port. Attach clear hose with a clamp to fitting. Place other end
of hose in a fuel container. Turn ignition switch to START position,
then release to RUN position without starting engine. Fuel transfer
pump should run for 25 seconds. After hose has been purged, watch for
any air bubbles in hose. If no bubbles exist, system is okay. If
bubbles exist, check fuel line, fittings and fuel module in tank.
Repair as necessary.
OVERFLOW VALVE
1) Fuel transfer pump delivers more fuel to fuel injection
pump than needed. Surplus fuel is routed back to fuel tank by overflow
valve. Overflow valve is used to secure fuel return line to side of
fuel injection pump. See Fig. 1. A sticking check valve in the
overflow valve may result in low power. Pressure release is set at 14
psi. (1.0 kg/cm
). If outlet valve is stuck closed, a FTC may set.
2) Clean area around outlet valve and fuel return line.
Remove valve from pump and fitting. Using regulated air pressure, test
valve by blowing into valve inlet. Valve should open at 14-16 psi. (1.
0-1.1 kg/cm
). If valve does not open, replace valve. Reduce air
pressure to 10 psi. (0.7 kg/cm). Valve should close. If valve does
not close, replace valve. Using NEW gaskets, install valve through
banjo fitting into fuel injection pump. Tighten valve to 24 ft. lbs.
(30 N.m).
FUEL INJECTOR & HIGH-PRESSURE FUEL LINES
WARNING: DO NOT allow diesel fuel to contact hot engine when checking
fuel injector, as high exhaust temperatures could cause fire.
Use care when working around high-pressure fuel lines, as
fuel is under extreme pressure and could penetrate skin,
causing personal injury. Wear safety goggles and protective
clothing when checking fuel injectors.

Minimum Compression Pressure
Dakota
2.5L ........................................................ (1)
3.9L, 5.2L & 5.9L ............................. 100 psi (690 kPa)\
Durango ........................................ 100 psi (690 kPa)\
Ram Pickup ..................................... 100 psi (690 kPa)\
Ram Van Ram Wagon .............................. 100 psi (690 kPa)\
Maximum Variation Between Cylinders ............................ ( 1)
( 1) - Information is not available from manufacturer.









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FUEL SYSTEM
FUEL PRESSURE RELEASE
WARNING: Fuel system is under high pressure. ALWAYS release fuel
pressure before attempting to open system for testing or
component replacement. DO NOT allow fuel to flow onto engine
or electrical parts while testing fuel system components.
Vehicles With Fuel Rail Test Port
1) Loosen fuel tank filler cap. Ensure ignition is off.
Remove protective cap from fuel rail test port.
2) Place one end of Fuel Pressure Release Hose (C-4799-1)
into an approved fuel container. Attach remaining end of hose to fuel
rail test port. Use care, as fuel system may be under pressure. Fuel
pressure will be released from fuel system. Remove hose, reinstall
protective cap, and fuel tank filler cap.
3) Wait 5 seconds. Use care when disconnecting fuel lines, as
some fuel pressure may still exist in fuel lines.
NOTE: One or more DTCs may set when fuel pump relay is removed.
Clear DTCs from PCM after fuel pressure release procedure. To
clear DTCs from PCM, see CLEARING DTCS under SELF-DIAGNOSTIC
SYSTEM in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article.
Vehicles Without Fuel Rail Test Port
1) Remove gas cap. Using a non-metallic tool, open flapper
valve in filler neck to relieve pressure. Remove fuel pump relay from
Power Distribution Center (PDC). Relays are identified on label under
PDC cover. Start and run engine until it stalls. Attempt to start
engine. Continue restarting engine until it will no longer run. Turn
ignition off.
CAUTION: DO NOT supply power to fuel injector for more than 4 seconds,
or fuel injector may be damaged.
2) Disconnect any fuel injector connector. Connect a jumper
wire between either fuel injector terminal and positive battery
terminal. Connect another jumper wire to other fuel injector terminal.
Momentarily touch other end of jumper wire to negative battery
terminal.
3) Place a shop towel under fuel line quick-connector at fuel
rail. Use care when disconnecting fuel lines, as some fuel pressure
may still exist in fuel lines. Disconnect fuel line quick-connector.
Reinstall fuel pump relay in PDC. Clear DTCs from PCM. To clear DTCs
from PCM, see CLEARING DTCS under SELF-DIAGNOSTIC SYSTEM in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
FUEL PRESSURE TEST

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

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