
BRAKE OPERATING SYSTEM 9-2 
BASIC OPERATING PRINCIPLES 9-2 
DISC BRAKES 9-2 
DRUM BRAKES 9-2 
POWERBOOSTERS 9-2 
BRAKE LIGHT SWITCH 9-3 
REMOVAL&INSTALLATION 9-3 
MASTER CYLINDER 9-3 
REMOVAL&INSTALLATION 9-3 
' BRAKE PEDAL ADJUSTMENTS 9-4 
POWER BRAKEBOOSTER 9-5 
REMOVAL &INSTALLATION 9-5 
PROPORTIONING VALVE 9-6 
REMOVAL &INSTALLATION 9-6 
BRAKEHOSESAND LINES 9-6 
REMOVAL&INSTALLATION 9-6 
BLEEDING BRAKESYSTEM 9-7 
DISC BRAKES 9-8 
BRAKE PADS 9-8 
REMOVAL &INSTALLATION 9-8 
INSPECTION 9-11 
BRAKE CALIPER 9-11 
REMOVAL & INSTALLATION 9-11 
OVERHAUL 9-12 
BRAKE DISC (ROTOR) 9-13 
REMOVAL &INSTALLATION 9-13 
INSPECTION 9-14 
DRUM BRAKES 9-15 
BRAKEDRUMS 9-16 
REMOVAL &INSTALLATION 9-16 
INSPECilON 9-16 
BRAKESHOES 9-16 
INSPECTION 9-16 
REMOVAL&INSTALLATION 9-17 
ADJUSTMENTS 9-18 
WHEELCYLINDERS 9-19 
REMOVAL &INSTALLATION 9-19 
. OVERHAUL 9-19 
PARKING BRAKE 9-20 
CABLE(S) 9-20 
REMOVAL&INSTALLATION 9-20 
ADJUSTMENT 9-22 
BRAKESHOES 9-23 
REMOVAL &INSTALLATION 9-23 
ADJUSTMENT 9-24 
ANTI-LOCKBRAKE SYSTEM 9-24 
GENERAL INFORMATION 9-24 
PRECAUTIONS 9-24 
DIAGNOSIS AND TESTING 9-24 
HYDRAULIC CONTROL UNIT 9-25 
REMOVAL&INSTALLATION 9-25 
ANTI-LOCK CONTROL UNIT 9-27 
REMOVAL&INSTALLATION 9-27 
SPEED SENSORS 9-28 
REMOVAL &INSTALLATION 9-28 
b G-SENSOR 9-29 
REMOVAL &INSTALLATION 9-29 
' TONE (EXCITER) RING 9-29 
REMOVAL&INSTALLATION 9-29 
BLEEDINGTHEABSSYSTEM 9-30 COMPONENTLOCATIONS 
DRUM BRAKECOMPONENTS 9-15 
SPECIFICATIONS CHARTS 
ABS DIAGNOSTICTROUBLE CODES 9-25 
BRAKE SPECIFICATIONS 9-31  

9-24 BRAKES 
Shoe-to-anchor spring (rear) 
e Forward 
69579946 Fig. 114 Shoe-to-anchor spring installation 
*When servicing drum 
brakes, only dissem- 
ble and assemble one side at a time, leaving 
the remaining side intact for reference. 
4. Remove the front and rear shoe-to-anchor 
springs. 
5. Remove the adjusting wheel spring and the 
adjuster. 
6. Remove the strut and the strut return spring. 
7. Remove the shoe hold-down cup, spring and 
pin. 
8. Remove the shoe and lining assembly. 
9. Unfasten the clips and the retaining bolts, 
then remove the parking brake cable(s). 
To install: 10. Installation is the reverse of the removal pro- 
cedure. 
11. Install the adjuster so the shoe adjusting bolt 
of the left hand wheel is attached toward the front of the vehicle and the shoe adjusting bolt of the right 
hand wheel is toward the rear of the vehicle. - 
12. The load on the respective shoe-to-anchor 
springs is different, so the spring in the figure has 
hen painteb, a> shm in the a~~0mparrying figure. 
1997-00 Diamante 
‘) See Figure 115 
1. Raise and safely support the vehicle securely 
on jackstands. 
2. Remove the caliper assembly. 
3. Remove the rear brake rotor. 
*When servicing drum brakes, only dissem- 
ble and assemble one side at a time, leaving 
the remaining side intact for reference. 
4. Remove the shoe hold-down spring retaining 
screw. 
5. Remove the shoe hold-down spring. 
6. Remove the shoe assembly from the backing 
plate. 
7. The installation is the reverse of removal. 
ADJUSTMENT 
1. Remove the floor console, release the lever 
and back off the cable adjuster locknut at the base of 
the lever. 
2. Raise the vehicle, support safely and remove 
the wheel. 3. Remove the hole plug in the brake rotor. 
4. Remove the brake caliper and hang out of the 
way with wire. Do not disconnect the fluid line. 
5. Use a suitable prybar to pry up on the self-ad- 
juskr V&I&I unti tie T&IT wi\ not tirn. 
6. Return the adjuster 5 notches in the opposite 
direction. Make sure the rotor turns freely with a 
slight drag. 
7. Install the caliper and check operation. 
9. Shoe 93159go3 Fig. 115 Exploded view of the parking brake 
shoes and related components-l 997-00 
Diamante 
The 4-Wheel Anti-lock Brake System (ABS) is an 
electronically operated, all wheel brake control sys- 
tem. Major components include the vacuum power 
brake booster, master cylinder, the wheel speed sen- 
sors, the Hydraulic Control Unit (HCU), Anti-lock 
control unit, a relay, and on the AWD Galant, a G sen- 
sor. 
The system is designed to retard wheel lockup 
during periods of high wheel slip when braking. Re- 
tarding wheel lockup is accomplished by modulating 
fluid pressure to the wheel brake units. When the 
control unit detects a variation in voltage across the 
wheel speed sensors, the ABS is activated. The con- 
trol unit opens and closes various valves located in- 
side the HCU. These valves, called dump and isola- 
tion valves, modulate the hydraulic pressure to the 
wheels by applying and venting the pressure to the 
brake fluid circuits. 
PRECAUTIONS 
l Certain components within the Anti-Lock Brake 
System (ABS) are not intended to be serviced or re- 
paired individually. Only those components with re- ! 
moval and installation procedures should be ser- 
viced. 
0 Do not use rubber hoses or other parts not 
specifically specified for an ABS system. When using 
repair kits, replace all parts included in the kit. Partial 
or incorrect repair may lead to functional problems 
and require the replacement of components. 
l Lubricate rubber parts with clean, fresh brake 
fluid to ease assembly. Do not use lubricated shop air 
to clean parts; damage to rubber components may re- 
sult. 
l Use only specified brake fluid from an un- 
opened container. 
l If any hydraulic component or line is removed 
or replaced, it may be necessary to bleed the entire 
system. 
l A clean repair area is essential. Always clean 
the reservoir and cap thoroughly before removing the 
cap. The slightest amount of dirt in the fluid may plug 
an orifice and impair the system function. Perform re- 
pairs after components have been thoroughly 
cleaned; use only denatured alcohol to clean compo- 
nents. Do not allow ABS components to come into 
contact with any substance containing mineral oil; 
this includes used shop rags. 
l The Anti-Lock control unit is a microprocessor 
similar to other computer units in the vehicle. Ensure 
that the ignition switch is 
OFF before removing or in- 
stalling controller harnesses. Avoid static electricity 
discharge at or near the controller. 
l If any arc welding is to be done on the vehicle, 
the control unit should be unplugged before welding 
operations begin. 
) See Figures 116 thru 123 
The diagnosis of the ABS system is rather complex 
and requires quite a few special tools including scan tools, special test harnesses and other special and 
expensive tools. Alternative methods and common 
sense can be substituted, however, We at Chilton feel 
that it is beyond the scope of the average do-it-your- 
selfer. If you experience the amber ANTI LOCK light 
on in the instrument cluster of your vehicle, check the 
fluid level in the master cylinder first. Low fluid level 
will usually illuminate the red BRAKE lamp in the in- 
strument cluster as well as, but not always, the amber 
ANTI LOCK lamp in the instrument cluster. The low 
fluid level could indicate a leak, but sometimes just 
indicates low, worn brake linings that have caused the 
caliper pistons and wheel cylinders to extend further, 
and thus using more fluid to exert force on them. In- 
spect the brake system for hydraulic fluid leaks and 
also inspect the brake linings for excessive wear. 
89579956 Fig. 116 You can connect a scan tool to the 
data link connector to retrieve ABS trouble 
codes  

TROUBLESHOOiNG 11-7 
4. Starter motor spins, but does not engage 
a. Check the starter motor for a seized or binding pinion gear. 
b. Remove the flywheel inspection plate and check for a damaged ring gear. 
Gasoline Engines 
1. Engine runs poor/y, hesiiates 
a. Check the engine ignition system operation and adjust if possible, or replace defective 
parts. 
b. Check for restricted fuel injectors and replace as necessary. 
c. Check the fuel pump output and delivery. Inspect fuel lines for restrictions. If the fuel 
pump pressure is below specification, replace the fuel pump. 
d. Check the operation of the engine management system and repair as necessary. 
2. Enfline lacks power 
a. Check the engine’s tune-up status. Note the tune-up specifications and check for items 
such as severely worn spark plugs; adjust or replace as needed. On vehicles with 
manually adjusted valve clearances, check for tight valves and adjust to specification. 
b. Check the air filter and air intake system. Replace the air filter if it is dirty or contami- 
nated. Check the fresh air intake system for restrictions or blockage. 
c. Check the operation of the engine fuel and ignition management systems. Check the 
sensor operation and wiring. Check for low fuel pump pressure and repair or replace 
components as necessary. 
d. Check the throttle linkage adjustments. Check to make sure the linkage is fully open- 
ing the throttle. Replace any worn or defective bushings or linkages. 
e. Check for a restricted exhaust system. Check for bent or crimped exhaust pipes, or in- 
ternally restricted mufflers or catalytic converters. Compare inlet and outlet tempera- 
tures for the converter or muffler. If the inlet is hot, but outlet cold, the component is 
restricted. 
f. Check for a loose or defective knock sensor. A loose, improperly torqued or defective 
knock sensor will decrease spark advance and reduce power. Replace defective knock 
sensors and install using the recommended torque specification. 
g. Check for engine mechanical conditions such as low compression, worn piston rings, 
worn valves, worn camshafts and related parts. An engine which has severe mechani- 
cal wear, or has suffered internal mechanical damage must be rebuilt or replaced to re- 
store lost power. 
h. Check the engine oil level for being overfilled. Adjust the engine’s oil level, or change 
the engine oil and filter, and top off to the correct level. 
i. Check for an intake manifold or vacuum hose leak. Replace leaking gaskets or worn 
vacuum hoses. 
j. Check for dragging brakes and replace or repair as necessary. 
k. Check tire air pressure and tire wear. Adjust the pressure to the recommended set- 
tings. Check the tire wear for possible alignment problems causing increased rolling 
resistance, decreased acceleration and increased fuel usage. 
I. Check the octane rating of the fuel used during refilling, and use a higher octane rated 
fuel. 
3. Poor fuel economy 
a. Inspect the air filter and check for any air restrictions going into the air filter housing. 
Replace the air filter if it is dirty or contaminated. 
b. Check the engine for tune-up and related adjustments. Replace worn ignition parts, 
check the engine ignition timing and fuel mixture, and set to specifications if possible. 
c. Check the tire size, tire wear, alignment and tire pressure. Large tires create more 
rolling resistance, smaller tires require more engine speed to maintain a vehicle’s road 
speed. Excessive tire wear can be caused by incorrect tire pressure, incorrect wheel 
alignment or a suspension problem. All of these conditions create increased rolling 
resistance, causing the engine to work harder to accelerate and maintain a vehicle’s 
speed. 
d. Inspect the brakes for binding or excessive drag. A sticking brake caliper, overly ad- 
justed brake shoe, broken brake shoe return spring, or binding parking brake cable or 
linkage can create a significant drag, brake wear and loss of fuel economy. Check the 
brake system operation and repair as necessary. 
4. Engine runs on (diesels) when turned off 
a. Check for idle speed set too high and readjust to specification. 
b. Check the operation of the idle control valve, and replace if defective. 
c. Check the ignition timing and adjust to recommended settings. 
Check for defective 
sensors or related components and replace if defective. 
d. Check for a vacuum leak at the intake manifold or vacuum hose 
and replace defective 
gaskets or hoses. 
e. Check the engine for excessive carbon build-up in the combustion chamber. Use a 
recommended decarbonizing fuel additive or disassemble the cylinder head to remove 
the carbon. 
f. Check the operation of the engine fuel management system and replace defective sen- 
sors or control units. 
g. Check the engine operating temperature for overheating and repair as necessary. 5. Engine knocks and pinfls during heavy accele/ation, and on steep hills 
a. Check the octane rating of the fuel used during refilling, and use a higher octane rated 
fuel. 
b. Check the ignition timing and adjust to recommended settings. Check for defective 
sensors or related components and replace if defective. 
c. Check the engine for excessive carbon build-up in the combustion chamber. Use a 
recommended decarbonizing fuel additive or disassemble the cylinder head to remove 
the carbon. 
d. Check the spark plugs for the correct type, electrode gap and heat range. Replace worn 
or damaged spark plugs. For severe or continuous high speed use, install a spark plug 
that is one heat range colder. 
e. Check the operation of the engine fuel management system and replace defective sen- 
sors or control units. 
f. Check for a restricted exhaust system. Check for bent or crimped exhaust pipes, or in- 
ternally restricted mufflers or catalytic converters. Compare inlet and outlet tempera- 
tures for the converter or muffler. If the inlet is hot, but outlet cold, the component is 
restricted. 
6. Engine atxelerates, but vehicle does not gain speed 
a. On manual transmission vehicles, check for causes of a slipping clutch. Refer to the 
clutch troubleshooting section for additional information. 
b. On automatic transmission vehicles, check for a slipping transmission” Check the 
transmission fluid level and condition. If the fluid level is too high, adjust to the cor- 
rect level. If the fluid level is low, top off using the recommended fluid type. If the fluid 
exhibits a burning odor, the transmission has been slipping internally. Changing the 
fluid and filter may help temporarily, however in this situation a transmission may re- 
quire overhauling to ensure long-term reliability. 
Diesel Engines 
1. Engine runs pOOr!y a. Check the injection pump timing and adjust to specification. 
b. Check for air in the fuel lines or leaks, and bleed the air from the fuel system. 
c. Check the fuel filter, fuel feed and return lines for a restriction and repair as necessary. 
d. Check the fuel for contamination, drain and flush the fuel tank and replenish with fresh 
fuel. 
2. Enfline lacks power 
a. Inspect the air intake system and air filter for restrictions and, if necessary, replace the 
air filter. 
b. Verify the injection pump timing and reset if out of specification. 
c. Check the exhaust for an internal restriction and replace failed parts. 
d. Check for a restricted fuel filter and, if restricted, replace the filter. 
e. Inspect the fuel filler cap vent. When removing the filler cap, listen for excessive hiss- 
ing noises indicating a blockage in the fuel filler cap vents, If the filler cap vents are 
blocked, replace the cap. 
f. Check the fuel system for restrictions and repair as necessary. 
g. Check for low engine compression and inspect for external leakage at the glow plugs 
or nozzles. If no external leakage is noted, repair or replace the engine. 
ENGINE PERFORMANCE TROUBLESHOOTING HINTS When troubleshooting an engine running or performance condition, the mechanical 
condition of the engine should be determined before lengthy troubleshooting procedures 
are performed. 
The engine fuel management systems in fuel injected vehicles rely on electronic sen- 
sors to provide information to the engine control unit for precise fuel metering. Unlike 
carburetors, which use the incoming air speed to draw fuel through the fuel metering jets 
in order to provide a proper fuel-to-air ratio, a fuel injection system provides a specific 
amount of fuel which is introduced by the fuel injectors into the intake manifold or intake 
port, based on the information provided by electronic sensors. 
The sensors monitor the engine’s operating temperature, ambient temperature and the 
amount of air entering the engine, engine speed and throttle position to provide informa- 
tion to the engine control unit, which, in turn, operates the fuel injectors by electrical 
pulses. The sensors provide information to the engine control unit using low voltage 
electrical signals. As a result, an unplugged sensor or a poor electrical contact could 
cause a poor running condition similar to a failed sensor. 
When troubleshooting a fuel related engine condition on fuel injected vehicles, care- 
fully inspect the wiring and electrical connectors to the related components. Make sure 
the electrical connectors are fully connected, clean and not physically damaged. If neces- 
sary, clean the electrical contacts using electrical contact cleaner. The use of cleaning 
agents not specifically designed for electrical contacts should not be used, as they could 
leave a surface film or damage the insulation of the wiring. 
The engine electrical system provides the necessary electrical power to operate the ve- 
hicle’s electrical accessories, electronic control units and sensors. Because engine man- 
agement systems are sensitive to voltage changes, an alternator which over or under- 
charges could cause engine running problems or component failure. Most alternators 
utilize internal voltage regulators which cannot be adjusted and must be replaced indi- 
vidually or as a unit with the alternator.  

II-14 TROUBLESHOOTING 
b. Check for low voltage at the bulb socket positive terminal or a poor ground. If voltage 
is low, or the ground marginal, trace the wiring to, and check for loose, damaged or 
corroded wires and electrical terminals; repair as necessary. 
c. Check the light switch operation and replace if necessary. 
1. Interior light inoperative 
a. Verify the interior light switch location and position(s), and set the switch in the cor- 
rect position. 
b. Check for battery voltage and ground at the interior light bulb socket. If battery voltage 
and ground are present, replace the bulb. If voltage is not present, check the interior 
light fuse for battery voltage. If the fuse is missing, replace the fuse. If the fuse has 
blown, or if battery voltage is present, refer to the wiring diagram to troubleshoot the 
cause for an open or shorted circuit. If ground is not present, check the door switch 
contacts and clean or repair as necessary. 
2. Interior light works intermittent/y 
a. Check the bulb for a damaged filament, and replace if damaged. 
b. Check the bulb and bulb socket for corrosion, and clean or replace the bulb and 
socket. 
c. Check for loose, damaged or corroded wires and electrical terminals; repair as neces- 
sary. 
d. Check the door and light switch operation, and replace if necessary. 
3. Interior light very dim 
a. Check the bulb and bulb socket for corrosion, and clean or replace the bulb and 
socket. 
b. Check for low voltage at the bulb socket positive terminal or a poor ground. If voltage 
is low, or the ground marginal, trace the wiring to, and check for loose, damaged or 
corroded wires and electrical terminals; repair as necessary. 
c. Check the door and light switch operation, and replace if necessary. 
1. One brake light inoperative 
a. PressPress the brake pedal and check for battery voltage and ground at the brake light 
bulb socket. If present, replace the bulb. If either battery voltage or ground is not pre- 
sent, refer to the wiring diagram to troubleshoot. 
2. Both brake lights inoperative 
a. Press the brake pedal and check for battery voltage and grou’nd at the brake light bulb 
socket. If present, replace both bulbs. If battery voltage is not present, check the brake 
light switch adjustment and adjust as necessary. If the brake light switch is properly 
adjusted, and battery voltage or the ground is not present at the bulb sockets, or at the 
bulb electrical connector with the brake pedal pressed, refer to the wiring diagram to 
troubleshoot the cause of an open circuit. 
3. One or both brake lights very dim 
a. Press the brake pedal and measure the voltage at the brake light bulb socket. If the 
measured voltage is close to the battery voltage, check for a poor ground caused by a 
loose, damaged, or corroded wire, terminal, bulb or bulb socket. If the ground is 
bolted to a painted surface, it may be necessary to remove the electrical connector and 
clean the mounting surface, so the connector mounts on bare metal. If battery voltage 
is low, check for a poor connection caused by either a faulty brake light switch, a 
loose, damaged, or corroded wire, terminal or electrical connector. Refer to the wiring 
diagram to troubleshoot the cause of a voltage drop. 
1. Warning light(s) stay on when the engine is started 
Ignition, Battery or Alternator Warning light a. Check the alternator output and voltage regulator operation, and replace as necessary. 
b. Check the warning light wiring for a shorted wire. 
Check Engine Light a. Check the engine for routine maintenance and tune-up status. Note the engine tune-up 
specifications and verify the spark plug, air filter and engine oil condition; replace 
and/or adjust items as necessary. 
b. Check the fuel tank for low fuel level, causing an intermittent lean fuel mixtur 
e. Top off fuel tank and reset check engine light. 
c. Check for a failed or disconnected engine fuel or ignition component, sensor or con- 
trol unit and repair or replace as necessary. 
d. Check the intake manifold and vacuum hoses for air leaks and repair as 
necessary. 
e. Check the engine’s mechanical condition for excessive oil consumption. 
Anti-Lock Braking System (ABS) Light a. Check the wheel sensors and sensor rings for debris, and clean as necessary. 
b. Check the brake master cylinder for fluid leakage or seal failure and replace as neces- 
sary. 
c, Check the ABS control unit, pump and proportioning valves for proper operation; re- 
place as necessary. 
d. Check the sensor wiring at the wheel sensors and the ABS control unit for a loose or 
shorted wire, and repair as necessary. 
brake Warning Light a. Check the brake fluid level and check for possible leakage from the hydraulic lines and 
seals. Top off brake fluid and repair leakage as necessary. 
b. Check the brake linings for wear and replace as necessary. 
c. Check for a loose or shot-ted brake warning light sensor or wire, and replace or repair 
as necessary. 
Oil Pressure Warning Light a. Stop the engine immediately. Check the engine oil level and oil filter condition, and 
top off or change the oil as necessary. 
b. Check the oil pressure sensor wire for being shorted to ground. Disconnect the wire 
from the oil pressure sensor and with the ignition in the ON position, but not running, 
the oil pressure light should not be working. If the light works with the wire discon- 
nected, check the sensor wire for being shorted to ground. Check the wire routing to 
make sure the wire is not pinched and check for insulation damage. Repair or replace 
the wire as necessary and recheck before starting the engine. 
c. Remove the oil pan and check for a clogged oil pick-up tube screen. 
d. Check the oil pressure sensor operation by substituting a known good sensor. 
e. Check the oil filter for internal restrictions or leaks, and replace as necessary. 
WARNING: If the engine is operated with oil pressure below the manufac- 
turer’s specification, severe (and costly) engine damage could occur. Low 
oil pressure can be caused by excessive internal wear or damage to the en- 
gine bearings, oil pressure relief valve, oil pump or oil pump drive mecha- 
nism. 
Before starting the engine, check for possible causes of rapid oil loss, such as leaking 
oil lines or a loose, damaged, restricted, or leaking oil filter or oil pressure sensor. If the 
engine oil level and condition are acceptable, measure the engine’s oil pressure using a 
pressure gauge, or determine the cause for the oil pressure warning light to function 
when the engine is running, before operating the engine for an extended period of time. 
Another symptom of operating an engine with low oil pressure is the presence of severe 
knocking and tapping noises. 
Parking Brake Warning Light a. Check the brake release mechanism and verify the parking brake has been fully re- 
leased. 
b. CheckCheck the parking brake light switch for looseness or misalignment. 
c. CheckCheck for a damaged switch or a loose or shorted brake light switch wire, and 
replace or repair as necessary. 
2. Warning light(s) flickers on and off when driving 
Ignition, Battery or Alternator Warning Light a. Check the alternator output and voltage regulator operation. An intermittent condition 
may indicate worn brushes, an internal short, or a defective voltage regulator. Replace 
the alternator or failed component. 
b. Check the warning light wiring for a shorted, pinched or damaged wire and repair as 
necessary. 
Check Engine Light a. Check the engine for required maintenance and tune-up status. Verify engine tune-up 
specifications, as well as spark plug, air filter and engine oil condition; replace and/or 
adjust items as necessary. 
b. Check the fuel tank for low fuel level causing an intermittent lean fuel mixture. Top off 
fuel tank and reset check engine light. 
c. Check for an intermittent failure or partially disconnected engine fuel and ignition 
component, sensor or control unit; repair or replace as necessary. 
d. Check the intake manifold and vacuum hoses for air leaks, and repair as necessary. 
e. Check the warning light wiring for a shorted, pinched or damaged wire and repair as 
necessary. 
Anti-Lock Braking System (ABS) Light a. Check the wheel sensors and sensor rings for debris, and clean as necessary. 
b. Check the brake master cylinder for fluid leakage or seal failure and replace as neces- 
sary. 
c. Check the ABS control unit, pump and proportioning valves for proper operation, and 
replace as necessary.  

TROUBLESHOOTING 1145 
d. Check the sensor wiring at the wheel sensors and the ABS control unit for a loose or 
shorted wire and repair as necessary. 
Brake Warninu Liaht a. Check the brakefluid~evel and check for possible leakage from the hydraulic lines and 
seals. Top off brake fluid and repair leakage as necessary. 
b. Check the brake linings for wear and replace as necessary. 
c. Check for a loose or shorted brake warning light sensor or wire, and replace or repair 
as necessary. 
Oil Pressure Warning Light a. Stop the engine immediately. Check the engine oil level and check for a sudden and 
rapid oil loss, such as a leaking oil line or oil pressure sensor, and repair or replace as 
necessary. 
b. Check the oil pressure sensor operation by substituting a known good sensor. 
c. Check the oil pressure sensor wire for being shorted to ground. Disconnect the wire 
from the oil pressure sensor and with the ignition in the ON position, but not running, 
the oil pressure light should not be working. If the light works with the wire discon- 
nected, check the sensor wire for being shorted to ground. Check the wire routing to 
make sure the wire is not pinched and check for insulation damage. Repair or replace 
the wire as necessary and recheck before starting the engine. 
d. Remove the oil pan and check for a clogged oil pick-up tube screen. 
Parking Brake Warning Light a. Check the brake release mechanism and verify the parking brake has been fully re- 
leased. 
b. Check the parking brake light switch for looseness or misalignment. 
c. Check for a damaged switch or a loose or shorted brake light switch wire, and replace 
or repair as necessary. 
3. Warning li#ht(s) inoperative with iflnition on, 
and engine not started 
a. Check for a defective bulb by installing a known good bulb. 
b. Check for a defective wire using the appropriate wiring diagram(s). 
c. Check for a defective sending unit by removing and then grounding the wire at the 
sending unit. If the light comes on with the ignition on when grounding the wire, re- 
place the sending unit. 
1. Turn siflnais or hazard iiflhts come on, but do not flash 
a. Check for a defective flasher unit and replace as necessary. 
2. Turn signals or hazard iiflhts do not function on either side 
a. Check the fuse and replace, if defective. 
b. Check the flasher unit by substituting a known good flasher unit. 
c. Check the turn signal electrical system for a defective component, open circuit, short 
circuit or poor ground. 
3. Turn siflnais or hazard lights only work on one side 
a. Check for failed bulbs and replace as necessary. 
b. Check for poor grounds in both housings and repair as necessary. 
4. One siflnai light does not work 
a. Check for a failed bulb and replace as necessary. 
b. Check for corrosion in the bulb socket, and clean and repair as necessary. 
c. Check for a poor ground at the bulb socket, and clean and repair as necessary. 
5. Turn signals flash too slowly 
a. Check signal bulb(s) wattage and replace with lower wattage bulb(s). 6. Turn signals flash too fast 
a, Check signal bulb(s) wattage and replace with higher wattage bulb(s). 
b. Check for installation of the correct flasher unit and replace if incorrect. 
7. Four-way hazard flasher indicator iiflhi inoperative 
a. Verify that the exterior lights are functioning and, if so, replace indicator bulb. 
b. Check the operation of the warning flasher switch and replace if defective. 
0. Turn signal indicator ii#ht(s) do not work in either direction 
a. Verify that the exterior lights are functioning and, if so, replace indicator bulb(s). 
b. Check for a defective flasher unit by substituting a known good unit. 
9. One turn signal indicator liflht does not work 
a. Check for a defective bulb and replace as necessary. 
b. Check for a defective flasher unit by substituting a known good unit. 
1. Horn does not operate 
a. Check for a defective fuse and replace as necessary. 
b. Check for battery voltage and ground at horn electrical connections when pressing the 
horn switch. If voltage is present, replace the horn assembly. If voltage or ground is 
not present, refer to Chassis Electrical coverage for additional troubleshooting tech- 
niques and circuit information. 
2. Horn has an unusual tone 
a. On single horn systems, replace the horn. 
b. On dual horn systems, check the operation of the second horn. Dual horn systems 
have a high and low pitched horn. Unplug one horn at a time and recheck operation. 
Replace the horn which does not function. 
c. Check for debris or condensation build-up in horn and verify the horn positioning. If 
the horn has a single opening, adjust the opening downward to allow for adequate 
drainage and to prevent debris build-up. 
1. Windshield wipers do not operate 
a. Check fuse and replace as necessary. 
b. Check switch operation and repair or replace as necessary. 
c. Check for corroded, loose, disconnected or broken wires and clean or repair as neces- 
sary. 
d. Check the ground circuit for the wiper switch or motor and repair as necessary. 
2. Windshield wiper motor makes a humming noise, gets hot or blows 
fuses 
a. Wiper motor damaged internally; replace the wiper motor. 
b. Wiper linkage bent, damaged or seized. Repair or replace wiper linkage as necessary. 
3. Windshield wiper motor operates, but one or both wipers fail to move 
a. Windshield wiper motor linkage loose or disconnected. Repair or replace linkage as 
necessary. 
b. Windshield wiper arms loose on wiper pivots. Secure wiper arm to pivot or replace 
both the wiper arm and pivot assembly. 
4. Windshield wipers will not park 
a. Check the wiper switch operation and verify that the switch properly interrupts the 
power supplied to the wiper motor. 
b. If the wiper switch is functioning properly, the wiper motor parking circuit has failed. 
Replace the wiper motor assembly. Operate the wiper motor at least one time before 
installing the arms and blades to ensure correct positioning, then recheck using the 
highest wiper speed on a wet windshield to make sure the arms and blades do not 
contact the windshield trim. 
1. Speedometer does not work to minimize sharp bends or kinks. 
If the sheathing has been 
damaged, replace the ca- 
a. Check and verify that the speedometer cable is properly seated into the speedometer ble assembly. 
assembly and the speedometer drive gear. b. Check the speedometer cable for adequate lubrication. Remove the cable, inspect for 
b. Check the speedometer cable for breakage or rounded-off cable ends where the cable damage, clean, lubricate and reinstall. If the cable has been damaged, replace the ca- 
seats into the speedometer drive gear and into the speedometer assembly. If damaged, ble. 
broken or the cable ends are rounded off, replace the cable. 
c. Check speedometer drive gear condition and replace as necessary. 3. Speedometer works intermittently 
d. Install a known good speedometer to test for proper operation. If the substituted a. Check the cable and verify that the cable is fully installed and the fasteners are secure. 
speedometer functions properly, replace the speedometer assembly. b. Check the cable ends for wear and rounding, and replace as necessary.