trip computer MITSUBISHI DIAMANTE 1900 Repair Manual

4-28 DRIVEABILITYAND EMISSIONS CONTROLS
Fig. 88 Plug the scan tool into the DLC un-
Fig. 89 Follow the directions on the scan
der the driver’s side of the instrument panel
tool screen to retrieve the DTC’s 3. Locate the Diagnostic Link Connector (DLC),
which is usually under the left-hand side of the in-
strument panel.
4. Start the engine and drive the vehicle until the
transaxle goes into the failsafe mode.
5. Park the vehicle, but do not turn the ignition
OFF. Allow it to idle.
6. Attach a voltmeter (analog or digital) to the test
terminals on the Diagnostic Link Connector (DLC).
The negative lead should be attached to terminal 4
and the positive lead to terminal 1.
7. Observe the voltmeter and count the flashes
(or arm sweeps if using an analog voltmeter); note
the applicable codes.
- 8. After all of the DTC(s) have been retrieved, fix
the applicable problems, clear the codes, drive the
vehicle, and perform the retrieval procedure again to
ensure that all of the codes are gone.
WITHASCANTOOL
Control module reset procedures are a very im-
portant part of OBD II System diaqnostics.
This step should be done at the end of any fault
code repair and at the end of any driveability repair.
Clearing codes can be performed by any of the
Fig. 90 in this case, we would choor- A ’ ma*-. . . * .
Trouble Codes to retrieve the DTC’s
-.- -
A mere mar
. . methods below: l Clear the control module memory with the
se l-
I I ng. vi me rtim In mts venicie contains no Generic Scan Tool (GST) l DTC’S Clear the control module memory with the ve-
L’-‘m iufacturer’s specific tester
The Federal government decided that it was time
to create a standard for vehicle diagnostic systems
codes for ease of servicing and to insure that certain
of the vehicle’s systems were being monitored for
emissions purposes. Since OBD II codes are stan-
dardized (they all contain one letter and four num-
bers), they are easy to decipher.
The OBD II system in the Mitsubishi models is de-
signed so that it will flash the DTC’s out on a volt-
meter (even though a scan tool is better). However,
the first two characters of the code are not used. This
is because the transaxle is a part of the powertrain, so
all transaxle related codes will begin with a P. Also, *The MIL will may also be de-activated for
some codes if the vehicle completes three
consecutive trips without a fault detected
with vehicle conditions similar to those pre-
sent during the fault.
WITHOUTASCAN TOOL
If there are still codes p
resent, either the codes
were not properly cleared f
:Are the codes identical to
those flashed out previous
I$‘), or the underlying
problem is still there (Are I
only some of the codes the
same as oreviouslv?).
since there are no overlapping numbers between SAE
and Mitsubishi codes, the second digit is also not
necessary.
The system flashes the codes o
ut ma series of
flashes in
three nmm mh nrnlll -- J.-lr-, ---.. ~.--
p corresponding to
one of the
three last diaits of the OBD II code. There-
fore, Code WJJ wuuw UC:
IIKWAJ WI III XVWI flashes, followed by five flashes, then by three
flashes. Each group of flashes is se
pause. All of the flashes are of the (
witi the or$, nvrontinn hoinn mm sented by z
long flash,
(shorted Tt SWIWI LIIW. rparated by a brief
;ame duration,
88, “rw”I.‘L’“‘I uv,,,y LUI”.
Zero is repre-
1 long flash. Therefore, seven flashes, one
two flashes would indicate a PO702 code
3 nnmn^r ,.:*....:I I r
SCANTOOLCODES
. YYY” I ‘I” I cuI”I”.J PO100 Mass or Volume Air Flow Circuit Malfunc-
Lb
non
PO101 Mass orVolume Air Flow Circuit
Range/Performance Problem
PO102 Mass or Volume Air Flow Circuit Low In-
Put
.
To retrieve the codes, perform the following: PO103 Mass or Volume Air Flow Circuit High In-
i Put
1. Perform the preliminary inspection, located PO104 Mass or Volume Air Flow Circuit Intermit-
-;
Vehicle speed es446e35 Fig. 92 For OBO ii code retrieval without us-
ing a scan tool on Mitsubishi models, con-
nect the DVOM and jumper wire as shown
In 1996, all Mitsubishi switched from an arbitrary
code listing and format, to the federally regulated On
Board Diagnostics 2nd Generation (OBD II) code sys-
tern. Normally, OBD II equipped vehicles do not have
the option of allowing the person servicing the vehi-
cle to flash the codes out with a voltmeter; usually a
scan tool is necessary to retrieve OBD II codes. Mit-
subishi, however, does provide this option, earlier in this section. This is very important, since a
loose or disconnected wire, or corroded connector
terminals can cause a whole slew of unrelated DTC’s
to be stored by the computer; you will waste a lot of
time performing a diagnostic “goose chase.”
2. Grab some paper and a pencil or pen to write
down the DTC’s when they are flashed out. tent
PO105 Manifold Absolute Pressure/Barometric
Pressure Circuit Malfunction
PO106 Manifold Absolute Pressure/Barometric
Pressure Circuit Range/Performance Problem
PO107 Manifold Absolute Pressure/Barometric
Pressure Circuit Low Input

11-18 GLOSSARY
COMBINATION MANIFOLD: An assembly which includes both the intake
and exhaust manifolds in one casting.
COMBINATION VALVE: A device used in some fuel systems that routes fuel
vapors to a charcoal storage canister instead of venting them into the atmos-
phere. The valve relieves fuel tank pressure
and allows fresh air into the tank
as the fuel level drops to prevent a vapor lock situation.
COMPRESSION RATIO: The ratio of the volume between the piston and
cylinder head when the piston is at the bottom of its stroke (bottom dead cen-
ter) and when the piston is at the top of its stroke (top dead center).
CONDENSER: 1. An electrical device which acts to store an electrical charge,
preventing voltage surges. 2. A radiator-like device in the air conditioning sys-
tem in which refrigerant gas condenses into a liquid, giving off heat.
CONDUCTOR: Any material through which an electrical current can be trans-
mitted easily.
CONTINUITY: Continuous or complete circuit. Can be checked with an ohm-
meter.
COUNTERSHAFT: An intermediate shaft which is rotated by a mainshaft and
transmits, in turn, that rotation to a working part.
CRANKCASE: The lower part of an engine in which the crankshaft and re-
lated parts operate.
CRANKSHAFT: Engine component (connected to pistons by connecting rods)
which converts the reciprocating (up and down) motion of pistons to rotary
motion used to turn the driveshaft.
CYLINDER: In an engine, the round hole in the engine block in which the
piston(s) ride.
CYLINDER BLOCK: The main structural member of an engine in which is
found the cylinders, crankshaft and other principle parts.
DEAD CENTER: The extreme top or bottom of the piston stroke.
DETONATION: An unwanted explosion of the air/fuel mixture in the com-
bustion chamber caused by excess heat and compression, advanced timing,
or an overly lean mixture. Also referred to as “ping”.
DIAPHRAGM: A thin, flexible wall separating two cavities, such as in a vac-
uum advance unit.
c
DIESELING: The engine continues to run after the car is shut off; caused by
fuel continuing to be burned in the combustion chamber.
DIFFERENTIAL: A geared assembly which allows the transmission of mo-
tion between drive axles, giving one axle the ability to rotate faster than the
other, as in cornering.
DIODE: An electrical device that will allow current to flow in one direction
only.
DISC BRAKE: A hydraulic braking assembly consisting of a brake disc, or
rotor, mounted on an axleshaft, anda caliper assembly containing, usually two GEAR RATIO: A ratio expressing the number of turns a smaller gear will
make to turn a larger gear through one revolution. The ratio is found by di-
brake pads which are activated by hydraulic pressure. The pads are forced viding the number of teeth on the smaller gear into the number of teeth on the
against the sides of the disc, creating friction which slows the vehicle. larger gear. DISTRIBUTOR: A mechanically driven device on an engine which is re-
sponsible for electrically firing the spark plug at a pre-determined point of the
piston stroke.
DOWEL PIN: A pin, inserted in mating holes in two different parts allowing
those parts to maintain a fixed relationship. .
DRUM BRAKE: A braking system which consists of two brake shoes and one
or two wheel cylinders, mounted on a fixed backing plate, and a brake drum,
mounted on an axle, which revolves around the assembly.
ELECTRONIC CONTROL UNIT (ECU): A diqital computer that controls en-
gine (and sometimes transmission‘, brake or other vehicle system) functions
based on data received from various sensors. Examples used by some man-
ufacturers include Electronic Brake Control Module (EBCM), Engine Control
Module (ECM), Powertrain Control Module (PCM) or Vehicle Control Mod-
ule (VCM).
ELECTRONIC IGNITION: A system in which the timing and‘firing of the
spark plugs is controlled by an electronic control unit, usually called a mod-
ule. These systems have no points or condenser,
END-PLAY: The clearance/gap between two components that allows for ex-
pansion of the parts as they warm up, to prevent binding and to allow space
for lubrication.
ENGINE: The primary motor or power apparatus of a vehicle, which converts
liquid or gas fuel into mechanical energy.
EXHAUST MANIFOLD: A set of cast passages or pipes which conduct ex-
haust gases from the engine.
FEELER GAUGE: A blade, usually metal, of precisely predetermined thick-
ness, used to measure the clearance between two parts.
FIRING ORDER: The order in which combustion occurs in the cylinders
of an engine. Also the order in which spark is distributed to the plugs by the
distributor.
FLOODING: The presence of too much fuel in the intake manifold and com-
bustion chamber which prevents the air/fuel mixture from firing, thereby caus-
ing a no-start situation.
FLYWHEEL: A heavy disc of metal attached to the rear of the crankshaft. It
smoothes the firing impulses of the engine and keeps the crankshaft turning
during periods when no firing takes place. The starter also engages the fly-
wheel to start the engine.
FOOT POUND (ft. Ibs. or sometimes, ft. lb.): The amount of energy or
work needed to raise an item weighing one pound, a distance of one foot.
FUSE: A protective device in a circuit which prevents circuit overload by break-
ing the circuit when a specific amperage is present. The device is constructed
around a strip or wire of a lower amperage rating than the circuit it is designed
to protect. When an amperage higher than that stamped on the fuse is present
in the circuit, the strip or wire melts, opening the circuit.