1999 DODGE RAM check engine light

ON-VEHICLE TESTING
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 article in GENERAL INFORMATION
before disconnecting battery.
DISABLING/ENABLING IGNITION & FUEL SYSTEMS
WARNING: To prevent engine from starting while performing tests,
always disable ignition and fuel systems.
Disabling Ignition & Fuel Systems
Remove Automatic Shutdown Relay (ASD) located in Power
Distribution Center (PDC). Refer to PDC cover for proper relay
location. PDC is located in engine compartment. On 5.9L diesel
engines, also disconnect fuel shutdown solenoid connector. Solenoid is
located behind upper intake manifold. See appropriate SYSTEM &
COMPONENT TESTING article in ENGINE PERFORMANCE section.
Enabling Ignition & Fuel Systems
When testing and/or repairs have been completed, verify
battery condition. Recharge battery as necessary, after starter tests
have been completed. Disconnect all test equipment. Install ASD relay.
On 5.9L diesel engines, reconnect fuel shutdown relay connector. On
all models, start engine several times to verify malfunction has been
corrected.
CRANKING TEST
NOTE: Ensure engine is at normal operating temperature. High
viscosity oil, extreme cold temperatures, or tight engine
will increase amperage draw.
1) Using a battery load tester, connect positive and negative
leads to battery. Connect inductive ammeter pick-up to positive
battery cable. Disable ignition and fuel systems. See
DISABLING/ENABLING IGNITION & FUEL SYSTEMS.
2) Ensure all lights and accessories are off. Place A/T in
Park position or M/T in Neutral position. Apply parking brake. Crank
engine and observe voltmeter reading. If voltage is more than 9.6
volts and cranking amperage draw is more than specified amps, proceed
to CIRCUIT RESISTANCE TESTS. See STARTER SPECIFICATIONS - CARS or
STARTER SPECIFICATIONS - TRUCKS.
3) If voltage is 12.5 volts or more and cranking amperage
draw is less than specified, check starter circuit components in the
following order:
starter solenoid, starter relay, starter relay circuit, park/neutral
position switch or transmission range sensor (A/T), clutch pedal
position switch (M/T), ignition switch, wiring harness and
connections.
CIRCUIT RESISTANCE TESTS
NOTE: If excessive resistance is not found in circuits being
tested, remove starter and proceed to BENCH TESTING.
Battery Connection Resistance Test
1) Disable vehicle ignition and fuel systems. See
DISABLING/ENABLING IGNITION & FUEL SYSTEMS. A voltmeter accurate to
one tenth of a volt will be needed for the following tests.

STE ER IN G C O LU M N S W IT C HES
1999 D odge P ic ku p R 1500
1999 ACCESSORIES & EQUIPMENT
CHRY - Steering Column Switches
Dakota, Durango & Ram Pickup
WARNING: Deactivate air bag system before performing any service
operation involving steering column components. See
appropriate AIR BAG RESTRAINT SYSTEMS article. DO NOT apply
electrical power to any component on steering column without
first disconnecting air bag module. Air bag may deploy. Wait
at least 2 minutes after disconnecting negative battery cable
before servicing air bag system. System reserve capacitor,
integral to ACM, maintains air bag system voltage for about 2
minutes after battery is disconnected. Servicing air bag
system before 2-minute period may cause accidental air bag
deployment and possible personal injury.
DESCRIPTION
Turn signal, hazard flasher, headlight beam selector,
headlight flash-to-pass, windshield wipe, pulse wipe and windshield
wash systems use a common switch assembly (multifunction switch)
mounted within upper steering column housing.
Ignition switch and lock cylinder are incorporated into an
assembly attached to side of steering column. Ignition switch assembly
can be serviced as a separate unit, but requires removal of lock
cylinder.
COMPONENT LOCATIONS
COMPONENT LOCATIONS








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Component Location
Combination Flasher Relay ........................... Junction Block
Horn ............................... In Right Front Corner Of Engine
Compartment
Horn Relay ............................ In Power Distribution Center
Junction Block ................. Under Left Side Of Instrument Panel
Power Distribution Center ...... In Left Side Of Engine Compartment,
On Left Inner Panel
Relay/Flasher Module ........ Under Right Side Of Instrument Panel,
Behind Glove Box









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TROUBLE SHOOTING
TURN SIGNAL AND HAZARD FLASHER SYSTEM
Bulbs Burn Out Rapidly
Check charging system. See appropriate GENERATORS &
REGULATORS article in STARTING & CHARGING SYSTEMS.
Hazard Flashers Inoperative
Blown fuse. Faulty hazard flasher. Open circuit in feed wire
to hazard switch. Faulty turn signal/hazard switch. Open or grounded
circuit in wiring to external lights.

FUEL DELIVERY
Fuel Filter/Water Separator
1) A restricted fuel filter/water separator may cause engine
starting problems, prevent engine from accelerating, low power or
White exhaust smoke.
2) When ignition is first turned on, 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 tachometer.
3) 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.
4) Rotate handle on drain valve forward, toward front of
vehicle to DRAIN position. Drain valve is located near top of fuel
filter/water separator.
5) If no water exists and a clean flow of diesel fuel exists,
rotate handle on drain valve back to CLOSE position. Go to next step.
If water exists, allow water to drain until clean flow of diesel fuel
exists. Rotate handle on drain valve back to CLOSE position. Go to
next step.
6) Verify fuel filter/water separator has been serviced
according to proper service schedule. See SERVICE & ADJUSTMENT
SPECIFICATIONS - TRUCKS article. Ensure pre-filter was cleaned when
fuel filter/water separator was serviced. Pre-filter is located at
bottom of fuel heater on driver's side of engine. No other testing
information is available from manufacturer.
Fuel Heater
1) Malfunctioning fuel heater may cause excessive wax build-
up in fuel filter/water separator during cold ambient temperatures.
Wax build-up may cause hard starting, prevent engine from
accelerating, low power, or Blue or White smoke.
2) Disconnect electrical connector at fuel heater. Fuel
heater is located in top of fuel filter housing. Using ohmmeter, check
resistance between electrical terminals on fuel heater.
3) Resistance should be about one ohm when fuel is cold, and
about 1000 ohms when fuel is warm. Replace fuel heater if resistance
is not within specification.
NOTE: Fuel heater receives battery voltage from fuel heater relay.
Fuel heater relay is located in Power Distribution Center
(PDC), next to left battery. Refer to PDC lid for relay
location. For testing of fuel heater relay, see RELAYS under
RELAYS & SOLENOIDS. Consult wiring diagram for wiring circuit
testing. See appropriate wiring diagram in WIRING DIAGRAMS
article.
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.
Repair fuel supply line or fuel return line if restricted or leaking.
2) Check for fuel leaking from weep hole on housing of fuel
transfer pump. Replace fuel transfer pump if fuel is leaking from weep
hole. Check fuel transfer pump for output pressure, pressure drop,
supply restriction, and air leaks.
NOTE: Separate pressure tests are necessary because transfer pump
operates at 2 pressure cycles, depending on whether engine is
running or cranking.


H - T E STS W /O C O DES - G ASO LIN E
1999 D odge P ic ku p R 1500
1999 ENGINE PERFORMANCE
CHRY - Trouble Shooting - No Codes - Gasoline
Avenger, Breeze, Caravan, Cirrus, Concorde, Dakota, Durango,
Intrepid, LHS, Neon, Ram Pickup, Ram Van, Ram Wagon,
Stratus, Town & Country, Sebring Convertible, Sebring
Coupe, Voyager, 300M
INTRODUCTION
Before diagnosing symptoms or intermittent faults, perform
basic diagnostic procedures in the appropriate BASIC DIAGNOSTIC
PROCEDURES article and applicable self-diagnostic tests in the
appropriate SELF-DIAGNOSTICS article. Use this article to diagnose
driveability problems existing when a hard fault code is not present.
NOTE: Some driveability problems may have been corrected by
manufacturer with a revised Powertrain Control Module (PCM).
Check with manufacturer for latest PCM application.
Symptom checks direct the technician to malfunctioning
component(s) for further diagnosis. A symptom should lead to a
specific component, system test or adjustment.
Use intermittent test procedures to locate driveability
problems that do not occur when the vehicle is being tested. These
problems may cause a noticeable driveability problem or cause the
Malfunction Indicator Light (MIL) to illuminate on some vehicles.
These test procedures should also be used if a soft (intermittent)
trouble code is present, but no problem is found during self-
diagnostic testing.
NOTE: For specific testing procedures, see appropriate SELF
-DIAGNOSTICS article. For specifications, see appropriate ON
-VEHICLE ADJUSTMENTS and SERVICE & ADJUSTMENT SPECIFICATIONS
articles.
SYMPTOMS
SYMPTOM DIAGNOSIS
Symptom checks cannot be used properly unless the problem
occurs while the vehicle is being tested. To reduce diagnostic time,
ensure basic diagnostic procedures and self-diagnostic were performed
before diagnosing a symptom. Symptoms available for diagnosis are as
follows:
* Hard Start
* Starts But Stalls
* Hesitation Or Stumble
* Surging
* Lack Of Power
* Knocking
* Engine Misfire
* Backfire
* Rough Or Erratic Idle
* Poor Fuel Economy
HARD START

Fig. 6: Locating Intake Manifold Air Heater Relays
Courtesy of Chrysler Corp.
Malfunction Indicator Light (MIL)
The MIL is located on the instrument panel, just below
tachometer and may also be referred to as the CHECK ENGINE light. MIL
comes on for a short period and then goes off as a bulb and wiring
circuit test each time ignition switch is turned to the ON position.
If Engine Control Module (ECM) receives an incorrect signal or
receives no signal from certain sensors or components, ECM will turn
on the MIL to warn the driver that a malfunction exists in the
electronic system.
Oil Pressure Gauge/Warning Light
Oil pressure gauge/warning light output from Engine Control
Module (ECM) to instrument cluster is routed on CCD Bus circuit.

signal to the transmission solenoid assembly for transmission
temperature sensor.
Generator Field
Engine Control Module (ECM) provides output signals to
generator field for regulating charging system voltage at 12.9-15.0
volts. ECM contains an internal electronic voltage regulator for
controlling the charging system voltage.
Generator Light
If Engine Control Module (ECM) senses a low charging system
condition, generator light on instrument panel (if equipped) will be
turned on. Generator light may also come on momentarily at low idle
speed when all accessories are on.
Malfunction Indicator Light (MIL)
The MIL is located on the instrument panel, just below
tachometer and may also be referred to as the CHECK ENGINE light. MIL
comes on for a short period and then goes off as a bulb and wiring
circuit test each time ignition switch is turned to the ON position.
If Engine Control Module (ECM) receives an incorrect signal or
receives no signal from certain sensors or components, ECM will turn
on the MIL to warn the driver that a malfunction exists in the
electronic system.
Overdrive Indicator Light (A/T Models)
Engine Control Module (ECM) delivers output signal to operate\
transmission overdrive indicator (O/D OFF) light in accordance with
position of the transmission overdrive switch. If overdrive is turned
off with transmission overdrive switch, transmission overdrive
indicator light will be turned on. Transmission overdrive indicator
light is located on instrument panel, just below the speedometer.
Tachometer
Engine Control Module (ECM) delivers output signal to operate\
tachometer on instrument panel to indicate engine RPM.
Transmission Overdrive Solenoid (A/T Models)
Engine Control Module (ECM) delivers output signal to
transmission overdrive solenoid for controlling transmission overdrive
shifts. Transmission overdrive solenoid is located on transmission
valve body.
Transmission Relay (A/T Models)
Transmission relay may be referred to as transmission control
relay or transmission 12-volt supply relay. Transmission relay ground
circuit is controlled by the Engine Control Module (ECM). When ground
circuit is completed, transmission relay supplies voltage to solenoid
assembly on the transmission. Transmission relay is located in power
distribution center at driver's side front corner of engine
compartment, near the battery.
Transmission Temperature Warning Light (A/T Models With
Heavy-Duty Transmission)
Engine Control Module (ECM) delivers output signal to turn on\
transmission temperature warning light if transmission fluid
temperature is determined to be greater than 280
F (138C) by the
transmission temperature sensor. Transmission temperature warning
light is located on instrument panel, just below the tachometer.
Transmission Torque Converter Clutch Solenoid (A/T Models)
Engine Control Module (ECM) delivers an output signal to
operate transmission torque converter clutch solenoid for torque

using DLC and a scan tool. The DLC also provides a means to
communicate with various vehicle control modules, check system
operating conditions and to operate various system components.
MALFUNCTION INDICATOR LIGHT (MIL)
The MIL is located on the instrument panel, just below
tachometer and may also be referred to as the CHECK ENGINE light. MIL
comes on for a short period and then goes off as a bulb and wiring
circuit test each time ignition switch is turned to the ON position.
If Engine Control Module (ECM) receives an incorrect signal or
receives no signal from certain sensors or components, ECM will turn
on the MIL to warn the driver that a malfunction exists in the
electronic system.
MISCELLANEOUS CONTROLS
TRANSMISSION
Transmission Overdrive Solenoid (A/T Models)
Engine Control Module (ECM) operates transmission overdrive
solenoid for controlling transmission overdrive shifts. Transmission
overdrive solenoid is located on transmission valve body.
Transmission Torque Converter Clutch Solenoid (A/T Models)
Engine Control Module (ECM) operates transmission torque
converter clutch solenoid for torque converter lock-up. ECM uses
various input signals such as transmission temperature, output shaft
speed, central module timer, engine speed, APPS and brake switch
position to determine operation of transmission torque converter
clutch solenoid. Torque converter clutch solenoid is located on
transmission valve body.

Ram Pickup
Gasoline Models
Light-Duty (2)
Normal Service ..................... 30 .............. 37,500
Severe Service ..................... ( 1) ............. 12,000
Medium-Duty & Heavy-Duty
Normal Service ..................... 24 .............. 24,000
Severe Service ..................... ( 1) ............. 12,000
Diesel Models
Normal Service ....................... 24 .............. 24,000
Severe Service ....................... ( 1) ............. 12,000
Ram Van/Wagon
Normal Service ........................ ( 3) ................ ( 3)
Severe Service ........................ ( 1) ............. 12,000
( 1) - Monthly interval is not available from manufacturer.
( 2) - Light-duty applies to all 1500 models and 2500 models except
5.9L diesel or 8.0L engines. Medium-duty applies to 2500 and
3500 California models with 8.0L engine. Heavy-duty applies to
2500 and 3500 Federal models with 8.0L engine and all 3500
models with 5.9L gasoline engine.
( 3) - Normal service interval is not available from manufacturer.









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Transfer Case
Check transfer case fluid level when performing other
underhood services. Under normal service conditions or severe service
conditions change transfer case fluid at specified interval. See
TRANSFER CASE SERVICING INTERVALS table. Severe service conditions are
conditions such as long periods of engine idling, trailer towing, off-
highway operation, snow removal, or operating in dusty or excessively
hot conditions.
TRANSFER CASE SERVICING INTERVALS









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Application Months Miles
Dakota
Normal Service ....................... 30 ............... 37,500
Severe Service ....................... ( 1) .............. 36,000
Ram Pickup
Gasoline Models
Light-Duty ( 2)
Normal Service .................... 30 ............... 37,500
Severe Service .................... ( 1) .............. 36,000
Medium-Duty & Heavy-Duty
Normal Service .................... 36 ............... 36,000
Severe Service .................... ( 1) .............. 36,000
Diesel Models
Normal Service ...................... 36 ............... 36,000
Severe Service ...................... ( 1) .............. 36,000
( 1) - Monthly interval is not available from manufacturer.
( 2) - Light-duty applies to all 1500 models and 2500 models except
5.9L diesel or 8.0L engines. Medium-duty applies to 2500 and
3500 California models with 8.0L engine. Heavy-duty applies to
2500 and 3500 Federal models with 8.0L engine and all 3500
models with 5.9L gasoline engine.









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Power Take-Off (PTO) Adapter (Ram Pickup 2WD 2500 & 3500)
Check PTO adapter fluid level when performing other underhood
services. Service interval is not available from manufacturer.