(1) - Require replacement of units where dents restrict shock
or strut piston rod movement. If dents don't restrict
movement, no service is suggested or required. Especially
critical on mono-tube shocks.
( 2) - This condition can lead to damage of the piston rod,
which, in turn, causes premature piston rod seal wear.
( 3) - Only required if replacing cartridge.
( 4) - CAUTION: If the strut cartridge has been replaced previously,
the oil on the strut housing may be filler oil. The
technician must identify the source of the oil.
( 5) - If noise is isolated to shock or strut, suggest
replacement.
( 6) - Although shocks or struts may have contributed to tire
cupping, an inspection is needed of the entire suspension
system. If the shock or strut is found to be contributing
to the tire cupping, require replacement.
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SPINDLES
SPINDLE INSPECTION \
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require replacement of broken
part.
Attaching hardware
loose .................. A ... Require repair or replacement
of loose part.
Attaching hardware
missing ................ C .. Require replacement of missing
part.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A ..... Require replacement of part
with stripped threads.
Bent .................... B ............ Require replacement.
Broken .................. A ............ Require replacement.
Race seat area
undersized ............. B ............ Require replacement.
Scored .................. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
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SPRINGS - COIL, LEAF AND TORSION BAR
When springs are replaced, it is suggested, but not required,
that both springs on an axle be replaced to maintain equal height from
side to side and to provide a balanced ride and proper handling.
When variable rate springs are installed in place of
conventional coil springs, they must be installed in axle sets to
ensure proper handling, uniform ride, and proper chassis height.
Erroneous height measurements may result from: improper tire
inflation, non-standard tire or wheel size, and heavy load in vehicle
or trunk.
SPRING (COIL, LEAF AND TORSION BAR) INSPECTION
piston rod movement. If dents don't restrict movement, no
service is suggested or required. Especially critical on
mono-tube dampers.
(2) - This condition can lead to damage of the piston rod,
which, in turn, causes premature piston rod seal wear.
( 3) - If noise is isolated to damper, suggest replacement.
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STEERING GEARS (EXCEPT RACK AND PINION)
If diagnosis has determined that complete disassembly is
necessary to determine the extent of the system failure, the
suggestion may be made to rebuild or replace the power steering pump.
Repair or replacement of the following components may be required, if
performed as part of a power steering pump overhaul or rebuild service
to meet a minimum rebuild standard.
STEERING GEAR (EXCEPT RACK AND PINION) INSPECTION
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Condition Code Procedure
Attaching hardware
broken ................. A .. Require replacement of broken
part.
Attaching hardware
loose .................. A .. Require repair or replacement
of loose part.
Attaching hardware
missing ................ C ......... Require replacement of
missing part.
Attaching hardware
threads damaged ........ A .. Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A .... Require replacement of part
with stripped threads.
Binding ................. A ... Require repair or replacement
Flex coupler binding .... A ... Require repair or replacement
of coupler.
Flex coupler loose ...... A ... Require repair or replacement
of coupler.
Flex coupler
missing parts .......... A ... Require repair or replacement
of coupler.
Flex coupler
soft/spongy ............ A . Require replacement of coupler.
Flex coupler torn ....... A . Require replacement of coupler.
Fluid contaminated ...... B ........ ( 1) Require flushing and
refilling of the system.
Gasket leaking .......... A ... Require repair or replacement
of gasket.
Housing leaking ......... A ............ Require replacement.
Hydraulic fittings
leaking ................ A ... Require repair or replacement
of fittings.
Inadequate power assist . A .......... ( 2) Further inspection
required.
See note below.
Lash exceeds
manufacturer's
specifications .......... B .. Require repair or replacement.
Seal leaking ............ A ... Require repair or replacement
TIE ROD ENDS (INNER AND OUTER)
TRACK BARS
TRAILING ARMS
WHEEL BEARINGS, RACES AND SEALS
Wheel Alignment
WHEEL ALIGNMENT
Wheels and Tires
TIRES
VALVE STEMS
WHEEL ATTACHMENT HARDWARE
WHEELS (RIMS)
MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,
manufacturer-recommended, maintenance. We encourage participating
service and repair shops (including franchisees and dealers) to adopt
1) a Pledge of Assurance to their Customers and 2) the Motorist
Assurance Program Standards of Service. All participating service
providers have agreed to subscribe to this Pledge and to adhere to the
promulgated Standards of Service demonstrating to their customers that
they are serious about customer satisfaction.
These Standards of Service require that an inspection of the
vehicle's (problem) system be made and the results communicated to the\
customer according to industry standards. Given that the industry did
not have such standards, the Motorist Assurance Program successfully
promulgated industry inspection communication standards in 1994-95 for
the following systems: Exhaust, Brakes, ABS, Steering and Suspension,
Engine Maintenance and Performance, HVAC, and Electrical Systems.
Further, revisions to all of these inspection communication standards
are continually re-published. In addition to these, standards for
Drive Train and Transmissions have recently been promulgated.
Participating shops utilize these Uniform Inspection & Communication
Standards as part of the inspection process and for communicating
their findings to their customers.
The Motorist Assurance Program continues to work
cooperatively and proactively with government agencies and consumer
groups toward solutions that both benefit the customer and are
mutually acceptable to both regulators and industry. We maintain the
belief that industry must retain control over how we conduct our
business, and we must be viewed as part of the solution and not part
of the problem. Meetings with state and other government officials
(and their representatives), concerned with auto repair and/or
consumer protection, are conducted. Feedback from these sessions is
brought back to the association, and the program adjusted as needed.
To assure auto repair customers recourse if they were not
satisfied with a repair transaction, the Motorist Assurance Program
offers mediation and arbitration through MAP/BBB-CARE and other non-
(1) - Require replacement of units where dents restrict shock
or strut piston rod movement. If dents don't restrict
movement, no service is suggested or required. Especially
critical on mono-tube shocks.
( 2) - This condition can lead to damage of the piston rod,
which, in turn, causes premature piston rod seal wear.
( 3) - Only required if replacing cartridge.
( 4) - CAUTION: If the strut cartridge has been replaced previously,
the oil on the strut housing may be filler oil. The
technician must identify the source of the oil.
( 5) - If noise is isolated to shock or strut, suggest
replacement.
( 6) - Although shocks or struts may have contributed to tire
cupping, an inspection is needed of the entire suspension
system. If the shock or strut is found to be contributing
to the tire cupping, require replacement.
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SPINDLES
SPINDLE INSPECTION \
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\
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\
Condition Code Procedure
Attaching hardware
broken ................. A ... Require replacement of broken
part.
Attaching hardware
loose .................. A ... Require repair or replacement
of loose part.
Attaching hardware
missing ................ C .. Require replacement of missing
part.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A ..... Require replacement of part
with stripped threads.
Bent .................... B ............ Require replacement.
Broken .................. A ............ Require replacement.
Race seat area
undersized ............. B ............ Require replacement.
Scored .................. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
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\
\
\
\
SPRINGS - COIL, LEAF AND TORSION BAR
When springs are replaced, it is suggested, but not required,
that both springs on an axle be replaced to maintain equal height from
side to side and to provide a balanced ride and proper handling.
When variable rate springs are installed in place of
conventional coil springs, they must be installed in axle sets to
ensure proper handling, uniform ride, and proper chassis height.
Erroneous height measurements may result from: improper tire
inflation, non-standard tire or wheel size, and heavy load in vehicle
or trunk.
SPRING (COIL, LEAF AND TORSION BAR) INSPECTION
piston rod movement. If dents don't restrict movement, no
service is suggested or required. Especially critical on
mono-tube dampers.
(2) - This condition can lead to damage of the piston rod,
which, in turn, causes premature piston rod seal wear.
( 3) - If noise is isolated to damper, suggest replacement.
\
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\
\
\
\
STEERING GEARS (EXCEPT RACK AND PINION)
If diagnosis has determined that complete disassembly is
necessary to determine the extent of the system failure, the
suggestion may be made to rebuild or replace the power steering pump.
Repair or replacement of the following components may be required, if
performed as part of a power steering pump overhaul or rebuild service
to meet a minimum rebuild standard.
STEERING GEAR (EXCEPT RACK AND PINION) INSPECTION
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\
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\
Condition Code Procedure
Attaching hardware
broken ................. A .. Require replacement of broken
part.
Attaching hardware
loose .................. A .. Require repair or replacement
of loose part.
Attaching hardware
missing ................ C ......... Require replacement of
missing part.
Attaching hardware
threads damaged ........ A .. Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A .... Require replacement of part
with stripped threads.
Binding ................. A ... Require repair or replacement
Flex coupler binding .... A ... Require repair or replacement
of coupler.
Flex coupler loose ...... A ... Require repair or replacement
of coupler.
Flex coupler
missing parts .......... A ... Require repair or replacement
of coupler.
Flex coupler
soft/spongy ............ A . Require replacement of coupler.
Flex coupler torn ....... A . Require replacement of coupler.
Fluid contaminated ...... B ........ ( 1) Require flushing and
refilling of the system.
Gasket leaking .......... A ... Require repair or replacement
of gasket.
Housing leaking ......... A ............ Require replacement.
Hydraulic fittings
leaking ................ A ... Require repair or replacement
of fittings.
Inadequate power assist . A .......... ( 2) Further inspection
required.
See note below.
Lash exceeds
manufacturer's
specifications .......... B .. Require repair or replacement.
Seal leaking ............ A ... Require repair or replacement
Power Steering Pressure Switch
On 2.5L Dakota only, power steering pressure switch sends a
signal to PCM. PCM will raise idle speed to prevent stalling during
high power steering pressure (375-575 psi), low RPM conditions.
Serial Communication Interface (SCI) Receive
SCI receive circuit is a serial communication link used when
diagnosing vehicle using scan tool. PCM receives data and device
activation commands from scan tool on this circuit.
Throttle Position (TP) Sensor
TP sensor monitors opening angle of throttle blade. TP sensor
will vary output voltage from about .26 volt at minimum throttle
opening (idle), to about 4.5 volts at Wide Open Throttle (WOT). PCM
uses this information and other sensor inputs to determine engine
operation. In response, PCM will adjust fuel injection pulse width and
ignition timing.
Transmission Governor Pressure Sensor (A/T Models)
Sensor sends PCM a signal indicating governor pressure. PCM
uses signal as feedback for governor solenoid control.
Transmission Overdrive/Override (OD/OR) Switch (A/T Models)
On models with Overdrive (OD), PCM regulates 3-4 OD upshift
and downshift through OD solenoid. Transmission OD/OR switch is
mounted in instrument panel.
OD/OR switch is normally closed. If OD/OR switch is depressed
and it opens, transmission will not enter OD. Transmission will
downshift if it is in OD and OD/OR switch is depressed.
OD/OR switch circuit includes a transmission fluid
temperature sensor. If this sensor opens, transmission will not shift
into overdrive, or will downshift if already in overdrive.
Transmission Temperature Sensor (A/T Models)
Transmission temperature sensor monitors transmission fluid
temperature and sends an input signal to PCM. Input signal is used for
controlling torque converter clutch operation, overdrive shifts, low
temperature shift compensation, wide open throttle shift strategy and
governor pressure. Transmission temperature sensor is located in
transmission valve body, incorporated into governor pressure sensor.
If transmission fluid temperature is more than 260
F (126C),
PCM forces a 4-3 downshift and engages torque converter clutch until
fluid cools. Once fluid cools to less than 230
F (110C), PCM allows a
3-4 shift. PCM prevents torque converter clutch engagement and
overdrive operation when fluid temperature is less than 50
F (10C).
Vehicle Speed Sensor (VSS)
VSS generates 8 pulses per sensor revolution. VSS input is
used by PCM to determine vehicle speed and distance traveled, and to
maintain set speed during cruise control operation.
PCM interprets speed sensor input along with TP sensor closed
throttle input. This enables PCM to determine if a closed throttle
deceleration or normal throttle idle (vehicle stopped) condition
exists. During deceleration, PCM controls IAC motor to maintain a
desired MAP value. During idle (vehicle stopped), PCM controls IAC
motor to maintain a desired idle speed.
OUTPUT SIGNALS
NOTE: Each vehicle may be equipped with different combinations of
computer-controlled components. The following components may
NOT be used on all models. To determine component location
and output usage on a specific model, see appropriate wiring
operating. When ground is supplied to injector by PCM, armature and
pintle inside injector move a short distance against spring and open a
small orifice. Since fuel is under high pressure, a fine spray is
developed.
Modes Of Operation
As input signals to PCM change, PCM adjusts its response to
output devices. Modes of operation come in 2 types, open loop and
closed loop. In open loop mode, PCM is not using input from HO2S and
is responding to preset programming to determine injector pulse width
and ignition timing. In closed loop mode, PCM adjusts ignition timing
and uses input from HO2S to fine tune injector pulse width.
The following inputs may be used to determine PCM mode:
* A/C Control Positions
* A/C Switch
* Battery Voltage
* Brake Switch
* Camshaft Position (CMP) Sensor
* Crankshaft Position (CKP) Sensor
* Engine Coolant Temperature (ECT) Sensor
* Engine Speed (RPM)
* Heated Oxygen Sensor (HO2S)
* Intake Air Temperature (IAT) Sensor
* Manifold Absolute Pressure (MAP) Sensor
* Park/Neutral (P/N) Switch
* Starter Relay
* Throttle Position (TP) Sensor
* Vehicle Speed Sensor (VSS)
From these inputs, PCM determines which mode vehicle is in
and responds appropriately. Not all inputs are used in all modes or by
all models. Modes of operation are:
* Ignition Switch On (Engine Not Running) - This is an open
loop mode. PCM pre-positions IAC motor based on ECT sensor
input. PCM determines atmospheric pressure from MAP sensor
and determines basic fuel strategy. PCM modifies fuel
strategy according to IAT sensor, ECT sensor and TP sensor
inputs. PCM activates ASD relay, which in turn activates fuel
pump for only 2 seconds unless engine is cranked. PCM also
energizes HO2S heater element for approximately 2 seconds
unless engine is cranked.
* Engine Start-Up - This is an open loop mode. When starter is
engaged, PCM receives input from battery voltage, ignition
switch, CKP sensor, CMP sensor, ECT sensor, IAT sensor, MAP
sensor and TP sensor. Based on these inputs, voltage is
applied to fuel injectors with PCM controlling injection
sequence, rate, and pulse width. PCM provides ground for
injectors to fire in proper order.
PCM determines proper ignition timing according to input
received from CKP sensor. If PCM does not receive CKP sensor signal
within 3 seconds after engine begins cranking, fuel injection system
is shut down and a Diagnostic Trouble Code (FTC) is set in PCM memory.\
* Engine Warm-Up - This is an open loop mode. PCM determines
injector pulse width using input information from battery
voltage, CKP sensor, CMP sensor, ECT sensor, IAT sensor, MAP
sensor and TP sensor. PCM also monitors A/C request and P/N
switch (A/T only) for fuel calculation. PCM controls engine
idle speed through IAC motor. PCM controls ignition timing
based on CKP sensor input.
PCM also operates A/C compressor clutch (if A/C is requested)\
through A/C clutch relay. When engine reaches operating temperature,
vehicle will go into idle mode and PCM will begin monitoring HO2S
input and go into closed loop operation.
* Idle - When engine is at operating temperature, this is a
closed loop mode. In idle mode, PCM now adds HO2S signal to
array of inputs used in ENGINE WARM-UP mode. PCM maintains
correct air/fuel ratio by adjusting injector pulse width and
ignition timing. PCM also controls A/C clutch operation (if
A/C is requested).
* Cruise - When engine is at operating temperature, this is a
closed loop mode. Using information from A/C switch, battery
voltage, CKP sensor, ECT sensor, IAT sensor, MAP sensor and
CMP sensor. PCM also monitors A/C request and P/N switch (A/T
only), TP sensor and VSS signals for fuel calculation. PCM
monitors HO2S and adjusts air/fuel ratio as needed. PCM
controls engine idle speed through IAC motor. PCM controls
spark advance as necessary.
* Acceleration - This is an open loop mode. When PCM
recognizes an abrupt increase in throttle position or
manifold pressure as a demand for increased engine output, it
increases injector pulse width in response to increased fuel
demand. HO2S signals are ignored.
* Deceleration - This is an open loop mode when engine is at
operating temperature and under deceleration. When PCM
receives inputs signaling a closed throttle and an abrupt
decrease in manifold pressure, it reduces injector pulse
width to lean air/fuel mixture. Under certain RPM and closed
throttle position conditions, HO2S signals are ignored and
PCM cuts off fuel injection until idle speed is reached. PCM
also drives IAC motor for smooth transition to idle mode.
* Wide Open Throttle - This is an open loop mode. When PCM
senses wide open throttle, it grounds fuel injectors in
sequence, it ignores HO2S input and it controls pulse width
to supply a pre-determined amount of additional fuel. PCM
also adjusts spark advance and disengages A/C clutch for
approximately 15 seconds.
* Ignition Switch Off - This is an open loop mode. PCM drives
IAC motor into position in anticipation of next start-up. All
outputs are turned off, no inputs are monitored and PCM shuts
down.
Sequential Fuel Injection (SFI)
Individual, electrically pulsed injectors (one per cylinder)
are located in intake manifold runners. These injectors are next to
intake valves in intake manifold. PCM controls injection timing based
on crankshaft position signal input. PCM regulates air/fuel mixture by
length of time injector stays open (pulse width) based on inputs from
HO2S, ECT sensor, MAP and other sensors.
IDLE SPEED
NOTE: DO NOT attempt to correct a high idle speed condition by
turning factory sealed throttle body throttle plate set
screw. This will not change idle speed of warm engine, but
may cause cold start problems due to restricted airflow.
Idle Air Control (IAC) Motor
IAC motor adjusts idle speed to compensate for engine load
and ambient temperature by adjusting amount of air flowing through by-
pass in back of throttle body. PCM uses ECT sensor, VSS, TP sensor and