DODGE RAM 1999 Service Repair Manual
Page 291 of 1691
NOTE: A leaking fuel injector or high-pressure fuel line may cause
a rough idle, Black smoke, poor engine performance, poor fuel
economy and fuel knock. Since a leaking high-pressure fuel
line may cause the same symptoms, check for leaking high
-pressure fuel line before checking fuel injector.
1) To determine which injector or line is malfuntioning,
start engine and check each cylinder output using scan tool. If scan
tool is not available, start engine and engine allow to idle. Loosen
high-pressure fuel line nut at each fuel injector in turn and listen
for a decrease in engine speed. Tighten high-pressure fuel line nut to
30 ft. lbs. (40 N.m). Go to next step.
2) To check for a leaking high-pressure fuel line, start
engine and allow engine to idle. Inspect high-pressure fuel lines and
connections for signs of fuel leakage by placing cardboard over high-
pressure fuel line and connection. Note if leak is being detected by
fuel being sprayed onto the cardboard. If leak exists, repair leak by
tightening high-pressure fuel line nut to 30 ft. lbs. (40 N.m) or
replacing high-pressure fuel line as necessary. If high-pressure fuel
line is replaced, bleed air from fuel system. See FUEL LINE BLEEDING
under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - TRUCKS -
DIESEL article. If no leaks are found, go to next step.
3) Remove suspect injector. See FUEL INJECTOR under FUEL
SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - TRUCKS - DIESEL article.
Test injector with a diesel fuel injector tester. Follow tester
instructions. Replace fuel injector if fuel injector opening (pop)
pressure is not 4250-4750 psi (299-334 kg/cm
). Replace injector if
any leaks are noted at 291 psi (20 kg/cm ) less than opening (pop)
pressure. Inspect injector for burrs, cracks, wear and plugging. Check
spray pattern. If any problems are noted, replace injector.
FUEL INJECTION PUMP TIMING
Improper fuel injection pump timing may result in low power,
excessive smoke and poor fuel economy. To check fuel injection pump
timing, see FUEL INJECTION PUMP TIMING in ADJUSTMENTS - TRUCKS -
DIESEL article.
INTAKE MANIFOLD AIR HEATER
NOTE: Intake manifold air heater is used to heat incoming air
before entering each cylinder. Warming of incoming air aids
in engine starting and improved driveability during cold
ambient temperatures. Engine Control Module (ECM) uses input
signals from various sensors for controlling intake manifold
air heater relays.
SUMMARY
If no faults were found while performing basic diagnostic
procedures, proceed to SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article. If no diagnostic trouble codes are found in self-diagnostics,
proceed to TROUBLE SHOOTING - NO CODES - DIESEL article for diagnosis
by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent
diagnostic procedures.
Page 292 of 1691
F - B ASIC T E STIN G - R W D - G ASO LIN E
1999 D odge P ic ku p R 1500
1999 ENGINE PERFORMANCE
CHRY - Basic Diagnostic Procedures Trucks & RWD Vans
Dakota, Durango, Ram Pickup, Ram Van, Ram Wagon
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.
INTRODUCTION
The following diagnostic steps will help prevent overlooking
a simple problem. This is also where to begin diagnosis for a no-start
condition.
The first step in diagnosing any driveability problem is
verifying the customer's complaint with a test drive under the
conditions the problem reportedly occurred.
Before entering self-diagnostics, perform a careful and
complete visual inspection. Most engine control problems result from
mechanical breakdowns, poor electrical connections or
damaged/misrouted vacuum hoses. Before condemning the computerized
system, perform each test listed in this article.
NOTE: Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM)\
with a minimum 10-megohm input impedance, unless stated
otherwise in test procedure.
PRELIMINARY INSPECTION & ADJUSTMENTS
VISUAL INSPECTION
Visually inspect all electrical wiring, looking for chafed,
stretched, cut or pinched wiring. Ensure electrical connectors fit
tightly and are not corroded. Ensure vacuum hoses are properly routed
and are not pinched or cut. Inspect air induction system for possible
vacuum leaks.
MECHANICAL INSPECTION
Compression
Ensure battery is fully charged. Warm engine to normal
operating temperature. Disconnect wire at ignition coil to prevent
engine from starting. Check engine compression with all spark plugs
removed and throttle wide open.
Check engine mechanical condition with a compression gauge,
vacuum gauge, or an engine analyzer. See engine analyzer manual for
specific instructions.
COMPRESSION SPECIFICATIONS
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Application Specification
Compression Ratio
Ram Pickup (8.0L) .......................................... 8.4:1\
All Others ................................................. 9.1:1
Normal Compression Pressure .................................... ( 1)
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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
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NOTE: For additional information on fuel pressure and fuel pump
testing procedures, see appropriate NO TROUBLE CODE (NTC)
TEST and NO START (NS) TEST in SELF-DIAGNOSTICS - JEEP,
TRUCKS & RWD VANS article.
Vehicles With Fuel Rail Test Port
1) Disconnect negative battery cable. Release fuel pressure.
See FUEL PRESSURE RELEASE. Install fuel pressure gauge with hose on
fuel pressure test port.
2) Start engine and allow to idle. Fuel pressure should be
44-54 psi (3.1-3.8 kg/cm
). If no fuel pressure exists and engine will
not start, fuel pump relay and control circuit may be defective. See
FUEL PUMP RELAY.
3) If fuel pressure exceeds specification, fuel pump is okay,
but fuel pressure regulator is defective. Replace fuel pressure
regulator. Fuel pressure regulator is incorporated with the fuel
filter. Fuel filter/fuel pressure regulator is located on top of fuel
tank, in fuel pump module. See REMOVAL, OVERHAUL & INSTALLATION -
TRUCKS & RWD VANS - GASOLINE article.
Vehicles Without Fuel Rail Test Port
1) Disconnect negative battery cable. Release fuel pressure.
See FUEL PRESSURE RELEASE. Fuel pressure gauge is installed between
fuel supply line and fuel line fitting on fuel rail.
2) To disconnect fuel supply line from fuel rail, ensure area
around fuel supply line and fuel rail are clean. Note direction of
latch clip installation. Latch clip is located on top of fuel supply
line at fuel rail. See Fig. 1. Using 2 screwdrivers, pry latch clip
upward, and remove from fuel rail.
3) Pull fuel supply line from fuel rail. Install Adapter
(6923) into fuel rail. Ensure adapter is fully seated in fuel rail.
Install latch clip into fuel rail, with latch clip fingers pointing
downward. If latch clip will not fully seat so latch clip fingers
extend downward below fitting on fuel rail, adapter may not be fully
seated in fuel rail.
4) Connect fuel supply line to adapter. Ensure fuel supply
line fully seats in adapter. Remove protective cap from test port, and
install Fuel Pressure Gauge/Hose (5069) at test port.
5) Start engine and allow to idle. Fuel pressure should be
44-54 psi (3.1-3.8 kg/cm
). If no fuel pressure exists and engine will
not start, fuel pump relay and control circuit may be defective. See
FUEL PUMP RELAY.
6) If fuel pressure exceeds specification, fuel pump is okay,
but fuel pressure regulator is defective. Replace fuel pressure
regulator. Fuel pressure regulator is incorporated with the fuel
filter. Fuel filter/fuel pressure regulator is located on top of fuel
tank, in fuel pump module. See REMOVAL, OVERHAUL & INSTALLATION -
TRUCKS & RWD VANS - GASOLINE article.
7) On all models, release fuel pressure. See FUEL PRESSURE
RELEASE. Remove latch clip. Remove test equipment. Before reinstalling
fuel supply line, ensure fuel supply line fitting and fitting on fuel
rail are clean.
8) Lubricate fuel supply line fitting and fitting on fuel
rail with engine oil. Install fuel supply line on fuel rail.
9) Install latch clip into fuel rail, with latch clip fingers
pointing downward. Ensure latch clip is fully seated. Latch clip
fingers should extend downward below fitting on fuel rail when fully
seated.
10) Pull on fuel supply line to ensure fuel supply line is
fully locked on fuel rail. Reinstall negative battery cable. Start
engine and check for fuel leaks.
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Fig. 1: Identifying Latch Clip & Installing Fuel Pressure Gauge
Courtesy of Chrysler Corp.
FUEL PUMP RELAY
On all models, if fuel pump relay or control circuit becomes
defective, a Diagnostic Trouble Code (FTC) may be stored in the PCM.
For additional information on diagnosis for fuel pump relay and
control circuit, see TEST TC-101A in SELF-DIAGNOSTICS - JEEP, TRUCKS &
RWD VANS article.
IGNITION CHECKS
NOTE: For ignition system spark testing and component testing, see
TEST NTC-2A in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article.
Page 296 of 1691
NO-START TESTS
NO-START TESTING PROCEDURES
For no-start testing procedures, see TEST NS-1A in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
IDLE SPEED & IGNITION TIMING
Idle speed and mixture are controlled by Powertrain Control
Module (PCM). No adjustment is required. PCM controls Idle Air Control\
(IAC) motor for proper idle speed. See TEST TC-25A in SELF-DIAGNOSTICS\
- JEEP, TRUCKS & RWD VANS article.
Ignition timing is controlled by PCM and is nonadjustable. If
vehicle is equipped with a distributor, DO NOT attempt to adjust
timing by rotating distributor. If distributor is rotated, fuel system
synchronization will be changed. If distributor is rotated or removed,
check fuel system synchronization. See FUEL SYSTEM SYNCHRONIZATION
under FUEL SYSTEM in ON-VEHICLE ADJUSTMENTS - TRUCKS & RWD VANS - CNG
& GASOLINE article.
SUMMARY
If no faults were found while performing basic diagnostic
procedures, proceed to SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article. If no diagnostic trouble codes are found in self-diagnostics,
proceed to TROUBLE SHOOTING - NO CODES - GASOLINE article for
diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.) or
intermittent diagnostic procedures.
Page 297 of 1691
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
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* 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.
Page 299 of 1691
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
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between terminal No. 9 (Light Blue wire) and chassis ground. Using
scan tool, read key-in ignition switch status. If scan tool does not
display KEY-IN IGNITION CHIME STATE: ON, replace CTM. If scan tool
displays KEY-IN IGNITION CHIME STATE: ON, repair open Light Blue wire
between CTM and ignition switch.
CHIME INOPERATIVE AT ALL TIMES
NOTE: Perform VERIFICATION TEST VER-1A after each repair.
Turn ignition on. Using scan tool, select BODY SYSTEM, BODY
COMPUTER then ACTUATORS. Actuate chime. If chime sounds, system is
currently functioning correctly. If chime does not sound, replace
Central Timer Module (CTM). CTM is located under left side of
instrument panel.
CHIME INOPERATIVE WITH EXTERIOR LIGHTS ON
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 ignition key. Using scan tool, read key-in ignition
chime state. If scan tool does not display KEY-IN IGNITION CHIME
STATE:
OFF, go to step 4). If scan tool displays KEY-IN IGNITION CHIME STATE:
OFF, go to next step.
2) Open driver's door. Using scan tool, read door ajar
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) Turn on headlights. If chime does not sound, repair open
headlight sense circuit (Light Blue wire) between CTM and headlight
switch. See appropriate wiring diagram in BODY CONTROL COMPUTER -
INTRODUCTION article. If chime sounds, system is currently functioning
correctly.
4) Open driver's door. Using scan tool, read door ajar
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.
5) 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.
6) 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.
CHIME INOPERATIVE WITH LOW OIL PRESSURE
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