oil reset CHEVROLET DYNASTY 1993 User Guide

the PCM determines crankshaft position, it begins
energizing the injectors in sequence.The auto shutdown (ASD) relay supplies battery
voltage to the injectors. The PCM provides the
ground path for the injectors. By switching the
ground path on and off, the PCM adjusts injector
pulse width. Pulse width is the amount of time the
injector is energized. The PCM adjusts injector pulse
width based on inputs it receives.
IGNITION COILÐPCM OUTPUT
The coil assembly consists of 3 molded coils to-
gether (Fig. 18). The coil assembly is mounted on the
intake manifold. High tension leads route to each
cylinder from the coil. The coil fires two spark plugs
every power stroke. One plug is the cylinder under
compression, the other cylinder fires on the exhaust
stroke. The PCM determines which of the coils to
charge and fire at the correct time.
The auto shutdown (ASD) relay provides battery
voltage to the ignition coil. The PCM provides a
ground contact (circuit) for energizing the coil. When
the PCM breaks the contact, the energy in the coil
primary transfers to the secondary, causing the
spark. The PCM will de-energize the ASD relay if it
does not receive the crankshaft position sensor and
camshaft position sensor inputs. Refer to Auto Shut-
down (ASD) Relay/Fuel Pump RelayÐPCM Output
in this section for relay operation.
RADIATOR FAN RELAYÐPCM OUTPUT
The radiator fan is energized by the PCM through
the radiator fan relay. The radiator fan relay is lo-
cated on the drivers side fender well near the PCM
(Fig. 14). The PCM grounds the radiator fan relay
when engine coolant reaches a predetermined tem-
perature or the A/C system head pressure is high.
SPEED CONTROL SOLENOIDSÐPCM OUTPUT
The speed control vacuum and vent solenoids are
operated by the PCM. When the PCM supplies a ground to the vacuum and vent solenoids, the speed
control system opens the throttle blade. When the PCM
supplies a ground only to the vent solenoid, the throttle
blade holds position. When the PCM removes the
ground from both the vacuum and vent solenoids, the
throttle blade closes. The PCM balances the two sole-
noids to maintain the set speed. Refer to Group 8H for
speed control information.
TACHOMETERÐPCM OUTPUT
The PCM supplies engine RPM to the instrument
panel tachometer through the CCD Bus. The CCD Bus
is a communications port. Various modules use the
CCD Bus to exchange information. Refer to Group 8E
for more information.
MODES OF OPERATION
As input signals to the PCM change, the PCM
adjusts its response to output devices. For example, the
PCM must calculate a different injector pulse width
and ignition timing for idle than it does for wide open
throttle (WOT). There are several different modes of
operation that determine how the PCM responds to the
various input signals. There are two different areas of operation, Open
Loop and Closed Loop. During Open Loop modes the PCM receives input
signals and responds according to preset PCM pro-
gramming. Input from the oxygen (O
2) sensor is not
monitored during Open Loop modes. During Closed Loop modes the PCM does monitor
the oxygen (O
2) sensor input. This input indicates to
the PCM whether or not the calculated injector pulse
width results in the ideal air-fuel ratio of 14.7 parts air
to 1 part fuel. By monitoring the exhaust oxygen
content through the O
2sensor, the PCM can fine tune
the injector pulse width. Fine tuning injector pulse
width allows the PCM to achieve optimum fuel
economy combined with low emissions. The 3.3L multi-port fuel injection system has the
following modes of operation:
² Ignition switch ON (Zero RPM)
² Engine start-up
² Engine warm-up
² Cruise (Idle)
² Acceleration
² Deceleration
² Wide Open Throttle
² Ignition switch OFF
The engine start-up (crank), engine warm-up, and
wide open throttle modes are OPEN LOOP modes.
Under most operating conditions, the acceleration,
deceleration, and cruise modes, with the engine at
operating temperature are CLOSED LOOP modes.
Fig. 18 Coil PackÐ3.3L Engine
Ä FUEL SYSTEMS 14 - 153

CAUTION: Be sure crossover bellcrank does NOT
move when tightening adjusting screw (Fig. 10).
CAUTION: Proper torque to the crossover cable ad-
justing screw is very important (Fig. 10).
(6) Remove lock pin from gearshift housing and re-
install lock pin (so long end is up) in gear shift hous-
ing. Tighten lock pin to 8 N Im (70 in. lbs.).
(7) Check for shift into first and reverse.
(8) Gearshift mechanism and cables are now func-
tioning properly.
IN-CAR TRANSAXLE DISASSEMBLE/ASSEMBLE
The following items can be serviced without remov-
ing the transaxle from the vehicle:
² Gear shift housing
² Synchronizers
² Intermediate shaft speed gears
² Input shaft
² Reverse idler gear and shaft
² Shift forks and pads
² Shift rails ²
Roller detents
² Speedometer pinion
² All external covers
Observe following procedure:
(1) Disconnect negative cable from battery.
(2) Remove both shift cables from shift cover levers.
(3) Remove left front wheel and tire assembly and
left splash shield. (4) Place drain pan under transaxle and remove
transaxle rear end cover. (5) Push out the fifth fork roll pin and slide the fifth
fork and synchronizer sleeve off the rail/hub. (6) Remove the fifth hub snap ring, hub assembly
and speed gear. (7) Remove fifth gear nut and fifth input gear.
(8) Remove the bearing retainer plate, interlock
plate and shuttles.
CAUTION: Before removing the gearshift housing
assembly, reverse the lock pin (so the long end is
down) and insert lock pin into the same threaded
hole. This procedure will save time when the gear
shift housing assembly is reinstalled. (9) Remove selector shaft housing bolts (note the two
pilot bolts) and remove housing. (10) Remove roller detents and springs, noting that
the rollers align with the shift rails. (11) Push out the 1-2 and 3-4 lug roll pins, remove
the reverse pivot lever and fifth rail C-Clip. If a roll
pin or C-Clip falls, be sure to remove it from the
bottom of the case. (12) Pull out the fifth shift rail and remove the fifth
shift lug and interlock pin. If the pin falls, be sure to
remove it from the bottom of the case. (13) Remove the intermediate shaft ball bearing
snap ring and the bearing support plate. (14) Remove reverse shift rail and lug assembly.
(15) Remove the reverse idler shaft and gear assem-
bly. (16) Rotate the 1-2 shift lug and rail, and 3-4 shift
lug towards the front of the vehicle. (17) Firmly grasp both the input and intermediate
shaft assemblies and pull them out of the transmission
with the 1-2 and 3-4 shift rails, lugs and forks. The differential assembly can only be serviced
by removing the complete transaxle from the
vehicle because bearing preload must be reset. The components listed in the first paragraph can now
be serviced. Refer to the appropriate subassembly
recondition section.
To reassemble the transaxle in the vehicle, reverse
the above procedure using the proper sealants. Fill the
transaxle with SAE 5W-30 engine oil to the bottom of
the fill hole in the end cover.
Fig. 9 Install Cables
Fig. 10 Adjusting Crossover Cable
21 - 4 TRANSAXLE Ä

first separator plate and watch carefully for the pis-
ton to move forward. The piston should return to its
original position after the air pressure is removed.
UNDERDRIVE CLUTCH
Because this clutch piston cannot be seen, its oper-
ation is checked by function. Air pressure is applied
to the low/reverse and the 2/4 clutches. This locks
the output shaft. Use a piece of rubber hose wrapped
around the input shaft and a pair of clamp-on pliers
to turn the input shaft. Next apply air pressure to
the underdrive clutch. The input shaft should not ro-
tate with hand torque. Release the air pressure and
confirm that the input shaft will rotate.
FLUID LEAKAGE-TORQUE CONVERTER HOUSING
AREA
(1) Check for source of leakage.
Since fluid leakage at or around the torque con-
verter area may originate from an engine oil leak,
the area should be examined closely. Factory fill
fluid is dyed red and, therefore, can be distinguished
from engine oil. (2) Prior to removing the transaxle, perform the
following checks: When leakage is determined to originate from the
transaxle, check fluid level prior to removal of the
transaxle and torque converter. High oil level can result in oil leakage out the vent
in the manual shaft. If the fluid level is high, adjust
to proper level. After performing this operation, inspect for leak-
age. If a leak persists, perform the following opera-
tion on the vehicle to determine if it is the torque
converter or transaxle that is leaking.
LEAKAGE TEST PROBE
(1) Remove torque converter housing dust shield.
(2) Clean the inside of torque converter housing
(lower area) as dry as possible. A solvent spray fol-
lowed by compressed air drying is preferable. (3) Fabricate and fasten test probe (Fig. 4) securely
to convenient dust shield bolt hole. Make certain
torque converter is cleared by test probe. Tool must be
clean and dry. (4) Run engine at approximately 2,500 rpm with
transaxle in neutral, for about 2 minutes. Transaxle
must be at operating temperature. (5) Stop engine and carefully remove tool.
(6) If upper surface of test probe is dry, there is no
torque converter leak. A path of fluid across probe
indicates a torque converter leak. Oil leaking under the
probe is coming from the transaxle torque converter
area. (7) Remove transaxle and torque converter assembly
from vehicle for further investigation. The fluid should
be drained from the transaxle. Re install oil pan (with
MOPAR tAdhesive Sealant) at specified torque.
Possible sources of transaxle torque converter area
fluid leakage are: (1) Torque converter hub seal.
² Seal lip cut, check torque converter hub finish.
² Bushing moved and/or worn.
² Oil return hole in pump housing plugged or omitted.
² Seal worn out (high-mileage vehicles).
(2) Fluid leakage at the outside diameter from pump
housing O-ring. (3) Fluid leakage at the front pump to case bolts.
Check condition of washers on bolts and use new bolts,
if necessary. (4) Fluid leakage due to case or front pump housing
porosity.
TORQUE CONVERTER LEAKAGE
Possible sources of torque converter leakage are:
² Torque converter weld leaks at the out side (periph-
eral) weld.
² Torque converter hub weld.
Hub weld is inside and not visible. Do not
attempt to repair. Replace torque converter. If the torque converter must be replaced, refer
to Torque Converter Clutch Break-in Procedure
in this section. This procedure will reset the
transmission control module break-in status.
Failure to perform this procedure may cause
transaxle shutter.
AIR PRESSURE TEST OF TRANSAXLE
Fabricate equipment needed for test as shown in
Figures 5 and 6. The transaxle should be prepared for pressure test as
follows after removal of the torque converter: (1) Plug dipstick tube and plug oil cooler line fitting.
Remove vent from manual shaft and in stall a 1/8 inch
pipe plug.Fig. 4 Leak Locating Test Probe Tool
Ä TRANSAXLE 21 - 97

If screen (c) appears, the transmission control mod-
ule has completed its break-in status program. Press
the enter key on the DRB II scan tool key pad to return
the status to the start of break-in. (9) After pressing the enter key a second time in step
8 a screen will appear that says ``RESET LU CLUTCH
ARE YOU SURE ?''. Press the enter key on the DRB II
scan tool key pad. The DRB II scan tool will then carry
out the reset command. (10) After the DRB II scan tool completes the reset
command, a screen will appear saying ``LU Clutch
Break-in Status has been RESET to Start''. This screen
will indicate that the reset procedure has been success-
fully completed. (11) Disconnect the DRB II scan tool from the blue
CCD Bus connector.
TRANSAXLE RECONDITION
Tag all clutch pack assemblies, as they are
removed, for reassembly identification.
CAUTION: Do not intermix clutch discs or plates as
the unit might then fail.
Fig. 1 Oil Pan Bolts
Fig. 2 Oil Pan
Fig. 3 Oil Filter
Fig. 4 Valve Body Attaching Bolts
Fig. 5 Push Park Rod Rollers from Guide Bracket
Ä TRANSAXLE 21 - 105

(8) With the front clutch plate assembly tight
against the shims, measure the air gap between ar-
mature plate and rotor-pulley face with feeler gauges
(Fig. 4). The air gap should be between 0.35 and 0.65
mm (0.013 and 0.025 inch). If proper air gap is not
obtained, add or subtract shims until desired air gap
is obtained.
(9) Install compressor shaft nut. Tighten nut to
17.5 N Im (155 in. lbs.) torque.
Shims may compress after tightening shaft bolt.
Check air gap in four or more places to verify if air
gap is still correct. Spin pulley for final check. (10) Install the compressor onto the mount.
CLUTCH/COIL BREAK-IN
After a new clutch/coil has been installed, cycle the
A/C clutch 20 times (5 sec. on and 5 sec. off). During
this procedure, run engine at 1500-2000 rpm and set
the A/C on the HIGH mode. This procedure (burnish-
ing) will seat the opposing friction surfaces and pro-
vide a higher clutch torque capability.
THERMAL LIMITER SWITCH
The Thermal Limiter Switch (Fig. 5) is bolted to
the side of the compressor case. It measures compres-
sor surface temperature and is used as a safety de-
vice to cut battery voltage to the compressor clutch
coil. This is performed if compressor case tempera-
ture is excessive. This switch is NOT USEDto cycle the clutch coil.
After the compressor has cooled to normal operating
temperature, the switch will reset.
DIAGNOSIS
The switch can remain bolted to the compressor for
testing. (1) Disconnect the wiring connectors from the ther-
mal limiter switch. (2) Using an ohmmeter, check for continuity be-
tween the two wiring leads. If continuity is not de-
tected, replace switch. Also check for possible
compressor overheating.
² Switch cut-out (no continuity) occurs at 125ÉC
6 3ÉC (255ÉF 637ÉF).
² Switch cuts back in (continuity) at 110ÉC 66ÉC
(230ÉF 642ÉF).
REMOVAL
The refrigerant system can remained fully charged
for thermal limiter switch replacement. After removing the thermal limiter switch, always
replace with a new unit. (1) Disconnect wiring connectors from switch.
(2) Remove the bolt retaining the switch holding
clamp and the switch to the side of the compressor
(Fig. 6). (3) Pry the switch from compressor case with a
screwdriver.
CLEANING
Remove silicone filler from the socket and thor-
oughly clean the socket with thinners.
INSTALLATION
(1) Place the new thermal limiter switch so that
the flat copper surface faces upward. (2) Apply the specified silicone filler (KE 347 RTV)
to the flat copper surface until the surface is evenly
covered. When silicone is applied, apply only from
tube and not by hand. (3) Install the thermal limiter switch into the
socket and secure it with the thermal protector (lim-
iting switch) fixing plate and bolt. Tighten the bolt
Fig. 4 Measuring Air Gap
Fig. 5 Thermal Limiter Switch
24 - 34 HEATING AND AIR CONDITIONING Ä