tow DODGE RAM 1999 Service Owner's Manual
[x] Cancel search | Manufacturer: DODGE, Model Year: 1999, Model line: RAM, Model: DODGE RAM 1999Pages: 1691, PDF Size: 40.34 MB
Page 148 of 1691

test system. Ensure A/C system is operating properly.
Orifice Tube Replacement Kit (Villager)
1) Discharge A/C system, using approved refrigerant
recovery/recycling equipment. Drain engine coolant to a level below
thermostat. Remove upper radiator hose and bracket to gain access to
condenser end of liquid line. Remove condenser-to-evaporator liquid
line from vehicle.
2) Locate orifice tube in metal portion of liquid line, at
indentation. See Fig. 20. Make a 4" (102 mm) index line on liquid line
with indentation at the midpoint. Cut a 2.5" (63.5 mm) section from
liquid line with indentation in the middle, at least 1" (25.4 mm) from\
start of closest bend. Clean out liquid line to remove contaminants.
3) Lubricate orifice tube replacement kit compression nuts
and rings with refrigerant oil and install on liquid line. See Fig. 21
. Ensure flow direction arrow points toward evaporator. Ensure index
line on liquid line is properly aligned for installation. Tighten
compression nuts to 65-70 ft. lbs. (88-95 N.m).
4) To complete installation, reverse removal procedure.
Lubricate "O" rings with refrigerant oil. Evacuate, charge and leak
test system. Ensure A/C system is operating properly.
Fig. 20: Locating Orifice Tube (Continental & Mustang Shown; Villager
Is Similar)
Courtesy of ford motor co.
Page 150 of 1691

evaporator inlet line and "O" rings with refrigerant oil. Lubricate
orifice tube and "O" ring with refrigerant oil. Insert orifice tube
into evaporator inlet line with short screen toward condenser.
2) Tighten liquid line nut to 18 ft. lbs. (24 N.m). To
complete installation, reverse removal procedure. Evacuate, charge,
and test system for proper operation.
Removal ("F" Body)
Discharge A/C system, using approved recovery/recycling
equipment. Disconnect negative battery cable. Disconnect A/C pressure
switch connector. Use a backup wrench to hold evaporator fitting, and
loosen evaporator liquid line fitting. Remove bolt. Disconnect
evaporator liquid line. Remove and discard "O" rings. Using needle-
nose pliers, remove orifice tube from evaporator inlet line.
Installation
1) Clean evaporator line fitting with refrigerant oil. Coat
inside of inlet line and evaporator line "O" rings with refrigerant
oil. Lubricate orifice tube and "O" ring with refrigerant oil and
insert them into inlet line. Insert orifice tube into evaporator inlet
line with long screen inlet end toward condenser.
2) Tighten bolt to 12 ft. lbs. (16 N.m). Tighten evaporator
line fitting to 28 ft. lbs. (38 N.m). To complete installation,
reverse removal procedure. Evacuate, charge, and test system for
proper operation.
Removal ("J" & "N" Body)
1) Locate orifice tube. See ORIFICE TUBE LOCATION &
REMOVER/INSTALLER APPLICATION table. Discharge A/C system, using
approved recovery/recycling equipment. On "J" body, remove upper
closeout panel. On "N" body, raise and support vehicle. On all models,
disconnect condenser-to-evaporator line at condenser outlet and
discard "O" rings.
2) Disconnect condenser-to-evaporator line clip on right side
body rail, behind engine mount. Remove orifice tube using Orifice Tube
Remover/Installer (J-26549-E) or needle-nose pliers.
3) If difficulty is encountered during removal of a plugged
or restricted orifice tube, remove as much residue as possible. Using
a heat gun, carefully apply heat 1/4" from dimples on condenser inlet
line. Be careful not to overheat line.
4) If A/C pressure switch is located near orifice tube,
remove switch to protect it from heat. While heat is being applied,
grip orifice tube using orifice tube remover/installer or needle-nose
pliers. Use a turning motion along with a push-pull motion to loosen
and remove orifice tube.
Installation
1) Coat inside of condenser inlet line and "O" rings with
refrigerant oil. Lubricate orifice tube "O" ring with refrigerant oil
and insert into condenser inlet line. Insert orifice tube into
condenser inlet line with shorter screen toward evaporator.
2) Connect condenser-to-evaporator line clip on right side
body rail. Lubricate "O" rings and connect condenser inlet line.
Tighten condenser inlet line nut to 12 ft. lbs. (16 N.m). Install
closeout panel. Evacuate, charge, and test system for proper
operation.
Removal ("W" Body)
1) Locate orifice tube. See ORIFICE TUBE LOCATION &
REMOVER/INSTALLER APPLICATION table. Remove air cleaner and duct
assembly. Discharge A/C system, using approved recovery/recycling
equipment. Disconnect negative battery cable. Disconnect ABS modulator
and A/C pressure sensor/fan switch electrical connectors.
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2) Disconnect liquid line/suction line bracket. Disconnect
liquid line at orifice tube. Remove orifice tube using specified
orifice tube remover/installer. See ORIFICE TUBE LOCATION &
REMOVER/INSTALLER APPLICATION table.
3) If difficulty is encountered during removal of a plugged
or restricted orifice tube, remove as much residue as possible. Using
a heat gun, carefully heat inlet line. If inlet line has small
dimples, apply heat 1/4" from dimples. Be careful not to overheat
line.
4) If A/C pressure switch is located near orifice tube,
remove switch to protect it from heat. While heat is being applied,
grip orifice tube using needle-nose pliers. Use a turning motion along
with a push-pull motion to loosen and remove orifice tube.
Installation
1) Coat inside of inlet line and "O" ring with refrigerant
oil. Lubricate orifice tube and "O" ring with refrigerant oil and
insert them into inlet line. Insert orifice tube into evaporator inlet
line with short screen toward condenser.
2) Tighten liquid line fitting at orifice tube to 20 ft. lbs.
(27 N.m). To complete installation, reverse removal procedure.
Evacuate, charge, and test system for proper operation.
Removal ("C" & "K" Series)
1) Discharge A/C system, using approved recovery/recycling
equipment. On models equipped with front A/C system only, remove front
grille. Using a backup wrench, loosen condenser-to-evaporator (liquid)\
line fitting at condenser and disconnect line.
2) On models equipped with rear A/C system, loosen condenser-
to-evaporator (liquid) line fitting between junction block and
evaporator. If necessary, remove air cleaner assembly.
3) On all models, remove and discard fitting "O" ring. Using
Orifice Tube Remover/Installer (J-26549-E), remove orifice tube from
liquid line. If difficulty is encountered during removal of a plugged
or restricted orifice tube, remove as much residue as possible.
4) Using a heat gun, carefully apply heat 1/4" from dimples
on liquid line. Be careful not to overheat line. If A/C pressure
switch is located near orifice tube, remove switch to protect it from
heat.
5) While heat is being applied, grip orifice tube using
orifice tube remover/installer. Use a turning motion along with a
push-pull motion to loosen and remove orifice tube.
Installation
1) Clean liquid line fitting with refrigerant oil. Coat
inside of liquid line and "O" ring with refrigerant oil. Lubricate
orifice tube and "O" ring with refrigerant oil and insert them into
liquid line. Insert longer orifice tube screen (inlet end) into
condenser outlet line first, toward condenser.
2) Tighten liquid line fitting to 18 ft. lbs. (24 N.m). To
complete installation, reverse removal procedure. Evacuate, charge,
and test system for proper operation.
Removal ("G", "L" & "M" Series)
1) Discharge A/C system, using approved recovery/recycling
equipment. Using a backup wrench, loosen evaporator inlet (liquid)
line fitting at evaporator. Disconnect inlet line. Remove and discard
"O" ring(s). Using Orifice Tube Remover/Installer (J-26549-E), remov\
e
orifice tube from liquid line.
2) If difficulty is encountered during removal of a plugged
or restricted orifice tube, remove as much residue as possible. Using
a heat gun, carefully apply heat 1/4" from dimples on liquid line. Be
careful not to overheat line.
Page 152 of 1691

3) If A/C pressure switch is located near orifice tube,
remove switch to protect it from heat. While heat is being applied,
grip orifice tube using orifice tube remover/installer. Use a turning
motion along with a push-pull motion to loosen and remove orifice
tube.
Installation
1) Clean liquid line fitting with refrigerant oil. Add one
ounce of refrigerant oil to system. Coat inside of liquid line and "O"
rings with refrigerant oil. Lubricate orifice tube and "O" ring with
refrigerant oil and insert them into liquid line. Insert shorter
orifice tube screen into liquid line first with long screen (inlet
end) toward condenser.
2) Tighten liquid line fitting to 20 ft. lbs. (27 N.m). To
complete installation, reverse removal procedure. Evacuate, charge,
and test system for proper operation.
Removal ("U" Series)
1) Remove air cleaner and duct assembly. Discharge A/C
system, using approved recovery/recycling equipment. Using a backup
wrench, loosen condenser outlet (liquid) line fitting at orifice tube.\
Disconnect liquid line. Remove and discard "O" rings. Using needle-
nose pliers, remove orifice tube from liquid line.
2) If difficulty is encountered during removal of a plugged
or restricted orifice tube, remove as much residue as possible. Using
a heat gun, carefully apply heat 1/4" from dimples on liquid line. Be
careful not to overheat line.
3) If A/C pressure switch is located near orifice tube,
remove switch to protect it from heat. While heat is being applied,
grip orifice tube using needle-nose pliers. Use a turning motion along
with a push-pull motion to loosen and remove orifice tube.
Installation
1) Clean liquid line fitting with refrigerant oil. Add one
ounce of refrigerant oil to system. Coat inside of liquid line and "O"
rings with refrigerant oil. Lubricate orifice tube and "O" ring with
refrigerant oil and insert them into liquid line. Insert orifice tube
into liquid line with long screen (inlet end) toward condenser.
2) Tighten liquid line fitting to 20 ft. lbs. (27 N.m). To
complete installation, reverse removal procedure. Evacuate, charge,
and test system for proper operation.
ORIFICE TUBE LOCATION & REMOVER/INSTALLER APPLICATION
\
\
\
\
\
\
\
Application Orifice Tube Orifice Tube
Location Remover/Installer
Cars
"C" Body ...................... ( 1) .................. J-26549-D
"E" & "K" Body ................ ( 1) .................. J-26549-D
"F" Body .............. Evaporator Inlet .. ....................
"G" Body .............. Evaporator Inlet ............. J-26549-E
"H" Body .............. Condenser Outlet ............. J-26549-D
"J" Body .............. Condenser Outlet ............. J-26549-E
"N" Body ( 2) .......... Condenser Outlet ............. J-26549-E
"W" Body ...................... ( 3) .................. J-26549-E
Trucks & Vans
"C" & "K" Series
With Rear A/C ........ Evaporator Inlet ............. J-26549-E
Without Rear A/C ..... Condenser Outlet ............. J-26549-E
"G" Series ............ Evaporator Inlet ............. J-26549-E
"L" & "M" Series ...... Evaporator Inlet ............. J-26549-E
"S" & "T" Series ...... Evaporator Inlet ............. J-26549-D
Page 155 of 1691

1) Manufacturer recommends flushing contaminated system using
one gallon of Ford A/C System Flushing Solvent (F4AZ-19579-A), a
Filter (FL-1A), an A/C Flusher Fitting Kit (014-00992). DO NOT reuse\
flushing solvent and filter, they are intended to be used on one
vehicle only.
2) Discharge A/C system, using approved refrigerant
recovery/recycling equipment. Flush specified A/C components using A/C
System Flusher (014-00991), according to manufacturer's operating
instructions.
3) If an A/C system flusher is not available to clean A/C
system, an in-line filter kit can be used. Filter kit is installed
before replacement compressor, accumulator/receiver-drier, muffler,
and thermal expansion valve/fixed orifice tube have been installed.
4) Filter kits are used with either a rubber lined suction
hose or with a nylon lined suction hose located between compressor and
evaporator. Rubber lined hose has a wall thickness of 1/4" and nylon
lined hose has a wall thickness of 1/8". See Fig. 22.
5) The filter kit for either type hose has 2 filters. A
temporary pancake filter and a permanent in-line suction filter.
Pancake filter is temporarily installed between condenser and
condenser-to-evaporator line. See Fig. 23. Permanent filter is
installed in suction line between accumulator and compressor.
6) Install replacement components (compressor, accumulator
and fixed orifice) with correct amount of refrigerant oil. See
COMPRESSOR REFRIGERANT OIL CHECKING article.
7) Cut suction hose between compressor and accumulator
(closer to compressor). Remove a length of suction hose to accommodate\
suction filter. Measure side wall of suction hose and install
appropriate filter with "O" rings and filter clamps. If side wall is
1/4", use in-line filter labeled USE WITH RUBBER INNER LINED HOSE. If
side wall is 1/8", use in-line filter labeled USE WITH NYLON INNER
LINED HOSE. Ensure arrow on filter is pointing in direction of
refrigerant flow. Tighten hose clamps to 54 INCH lbs. (6 N.m). See
Fig. 22 .
8) Install pancake filter in liquid line between condenser
and condenser-to-evaporator line. Ensure filter inlet (label) is
toward condenser. Evacuate, charge, and leak test A/C system. See
EVACUATING A/C SYSTEM, CHARGING A/C SYSTEM and LEAK TESTING. Check
filters and hoses for clearance from other engine components. Use tie
straps if necessary.
9) Place an external cooling fan in front of radiator. Select
MAX A/C operation and set blower motor speed to maximum. Start engine
and allow to idle. Ensure A/C is operating properly. Slowly increase
engine speed to 800 RPM, then 1000 RPM, and then to 1200 RPM. With
engine speed set to 1200 RPM, operate engine for one hour with A/C
system operating.
10) Stop engine. Discharge A/C system, using approved
refrigerant recovery/recycling equipment. Remove pancake filter, hoses
and fittings. Discard pancake filter. Reconnect liquid line, evacuate,
charge, and leak test A/C system. Ensure A/C system is operating
properly.
Page 178 of 1691

foot wires to terminals of a 12-volt battery. After air bag module
deploys, let module cool off and allow dust to settle before
approaching.
POST-COLLISION INSPECTION
When a vehicle has been involved in a collision, certain
components of the passive restraint system must be inspected or
replaced. See PASSIVE RESTRAINT SYSTEM INSPECTION article in the
GENERAL INFORMATION section for post-collision inspection information.
REMOVAL & INSTALLATION
* PLEASE READ THIS FIRST *
WARNING: Failure to follow air bag service precautions may
result in air bag deployment and personal injury. See
SERVICE PRECAUTIONS . After component replacement,
ensure proper system operation. See SYSTEM OPERATION CHECK.
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 in GENERAL INFORMATION
before disconnecting battery.
AIR BAG CONTROL MODULE (ACM)
WARNING: ACM contains impact sensor, which enables SRS to activate air
bag. To avoid accidental air bag deployment, DO NOT connect
ACM electrically to system unless it is bolted to vehicle.
Removal
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Remove bottom
of center console (ACM trim cover).
2) On M/T models, remove center console from floor panel
transmission tunnel. On A/T models, remove screws securing trim cover
to ACM mounting bracket. See Fig. 2. Pull top of trim cover rearward
to release snap clips from instrument panel support bracket.
3) On all models, loosen but do not remove screws on sides
that secure instrument panel support bracket to ACM mounting bracket.
See Fig. 3 .
4) Remove nuts securing support bracket to studs on lower
instrument panel. Disconnect wire harness retainer from hole in
support bracket. Pull top of support bracket away from instrument
panel studs and fold down over ACM until it is laying on floor panel.
Unplug wire harness connector from ACM.
CAUTION: Always replace ACM and ACM mounting bracket as an assembly.
Replacement ACM includes a NEW mounting bracket. DO NOT mount
NEW ACM to old mounting bracket.
5) Remove screws securing mounting bracket to floor panel
transmission tunnel. Remove ACM, mounting bracket and support bracket
as a unit from floor panel.
Installation
To complete installation, reverse removal procedure. Install
ACM with arrow pointing toward front of vehicle. Connect ACM
connectors, ensuring connectors are locked into position. Tighten ACM
Page 180 of 1691

CAUTION: When removing a deployed air bag, wear eye protection, rubber
gloves and a long-sleeve shirt. Powder residue from air bag
deployment may irritate skin and eyes.
CAUTION: Before removing steering wheel, position front wheels in
straight-ahead position and lock steering column by removing
ignition key. Failure to do so could damage clockspring or
cause clockspring to be off-centered. DO NOT hammer on
steering wheel during removal, or collapsible column could be
damaged.
Removal
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Air bag module
is mounted on face of steering wheel. Ensure wheels are pointed
straight-ahead and steering wheel is locked.
2) Remove air bag module-to-steering wheel screws from back
side of steering wheel. Lift air bag module and disconnect electrical
connectors from rear of module.
Installation
Connect air bag, cruise control and horn harness connectors
to rear of air bag module. Secure module to steering wheel. Tighten
air bag module-to-steering wheel screws to specification. See
TORQUE SPECIFICATIONS . DO NOT connect negative battery cable at this
time. Go to SYSTEM OPERATION CHECK .
PASSENGER-SIDE AIR BAG MODULE
Removal
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) Open glove box. Holding glove box door, push center of
glove box bin towards front of vehicle. Flex glove box bin far enough
so glove box stops will clear sides of instrument panel opening. Roll
glove box down until stop bumpers are beyond sides of instrument panel
opening. Release bin. Lift bottom of glove box upward to disengage
hinge hooks form hinge pins.
3) Remove 3 screws securing instrument panel glove box
opening upper trim strip to instrument panel glove box opening upper
reinforcement, then remove trim strip. Remove 4 screws that secure 2
plastic support brackets of passenger-side air bag door panel outlet
housing to glove box opening upper reinforcement.
4) Reach through and above glove box opening to access and
disconnect air bag module harness connector. Remove 2 screws securing
passenger-side air bag module front bracket to instrument panel
structural support. Remove 3 screws securing passenger-side air bag
module rear bracket to glove box opening upper reinforcement.
5) Using trim stick, gently pry passenger-side air bag door
(starting at lower left edge) away from instrument panel top cover.
Remove air bag module, air bag door and panel outlet housing and
barrel assembly from instrument panel as a unit.
Installation
To install, reverse removal procedure. Ensure air bag door is
securely attached to instrument panel. Ensure air bag harness
connector latches fully engaged. DO NOT connect negative battery cable
at this time. Go to SYSTEM OPERATION CHECK .
CLOCKSPRING
CAUTION: Failure to position wheels in the straight-ahead position
with steering wheel locked when removing steering wheel could
Page 181 of 1691

damage clockspring and/or require clockspring to be
readjusted.
NOTE: Clockspring is self-centering and will automatically lock in
the centered position when steering wheel is removed.
Adjustment is only required if centering position is
disturbed.
Removal
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) Clockspring is located behind steering wheel. See Fig. 1.
Ensure front wheels are in straight-ahead position. Lock steering
wheel. Remove air bag module. See AIR BAG MODULE.
3) Remove steering wheel nut. Using appropriate steering
wheel puller, remove steering wheel. When steering wheel is removed,
self-centering clockspring will automatically lock in place. Remove
upper and lower steering column shrouds to gain access to clockspring
wiring.
4) Remove knee bolster (if equipped). Disconnect Yellow 2-wa\
y
clockspring harness connector between clockspring and instrument panel
wiring harness, at base of steering column. See Fig. 13. Remove
clockspring by releasing 2 tabs on side of clockspring. Clockspring
cannot be repaired and must be replaced if faulty.
Installation
1) Snap clockspring onto steering column. If clockspring
centering adjustment is disturbed, adjust clockspring before
installing steering wheel. See CLOCKSPRING CENTERING under
ADJUSTMENTS. Connect clockspring wiring connectors. Install steering
column covers. Install knee bolster (if removed).
2) Position steering wheel on steering column. Ensure flats
on steering wheel hub fit formations on inside of clockspring. Pull
clockspring, cruise control switch (if equipped) and horn wires
through lower large holes and upper small holes in steering wheel.
3) Install steering wheel retaining nut and tighten to 45 ft.
lbs. (61 N.m). Connect horn and cruise control wires (if equipped).
Connect clockspring wire to air bag module. To ensure complete
connector connection, latching arms must be visible on top of
connector housing. DO NOT connect negative battery cable at this time.
Go to SYSTEM OPERATION CHECK .
PASSENGER AIR BAG DISARM (PAD) SWITCH
Removal & Installation
1) Before proceeding, see SERVICE PRECAUTIONS. Disable air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) If vehicle is equipped with automatic transmission, turn
ignition switch to UNLOCK position, set parking brake and place
transmission selector lever in LOW position. Tilt steering column to
lowest position (if equipped). Using trim stick, gently pry around
perimeter of cluster bezel and remove bezel.
3) Open glove box. Holding glove box door, push center of
glove box bin towards front of vehicle. Flex glove box bin far enough
so glove box stops will clear sides of instrument panel opening. Roll
glove box down until stop bumpers are beyond sides of instrument panel
opening. Release bin. Lift bottom of glove box upward to disengage
hinge hooks form hinge pins.
4) Reach through glove box opening to access and disconnect 2
passenger-side air bag disarm switch harness connectors. Connectors
are attached to bracket located on inboard glove box opening
reinforcement. See Fig. 4. Remove 3 screws retaining passenger-side
air bag disarm switch bezel to instrument panel.
Page 234 of 1691

between Black PCM harness connector C1 and transmission
pressure/temperature sensor harness connector. If resistance is
greater than 5 ohms, repair or replace transmission solenoid and
harness assembly. If resistance is 5 ohms or less, replace
transmission pressure/temperature sensor.
10) Reconnect all harness connectors. Using scan tool, read
TRANS TEMP voltage. If voltage is greater than 3.76 volts, replace
PCM. If voltage is 3.76 volts or less, conditions required to set DTC
P0713 are not present at this time. DTC P0713 sets when transmission
temperature sensor voltage at PCM is greater than 3.76 volts for 2.2
seconds. Possible causes are: open transmission temperature sensor
wiring, faulty connections, faulty transmission temperature sensor or
faulty PCM. Go to next step.
11) Inspect all related wiring and connectors. Repair as
necessary. If wiring and connectors are okay, see INACTIVE DTC
CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is complete.
DTC P0720: LOW OUTPUT SPEED SENSOR RPM ABOVE 15 MPH (EXCEPT
BR BODY)
Circuit Description
Circuit is monitored continuously while key is on, and gear
selector is not in Park or Neutral. Code sets if vehicle speed is
above 15 MPH and output shaft speed is below 60 RPM for 2.6 seconds as
measured from vehicle speed sensor.
Possible Causes
* Open output speed sensor ground circuit.
* Damaged ignition wiring.
* Open output speed sensor signal circuit.
* Short to ground in output speed sensor signal circuit.
* Park/Neutral switch code present.
* Malfunctioning sensor.
* Short to ground in output speed sensor ground circuit.
* Malfunctioning PCM.
* OSS harness intermittent defective.
Diagnostic Procedure
1) Using scan tool, check SPECIFIC GOOD TRIPS counter. If DTC
SPECIFIC GOOD TRIPS counter is not displayed or displayed count is not
"0", go to step 12). If DTC SPECIFIC GOOD TRIPS counter is displayed
and displayed count is "0", go to next step.
2) Record all DTCs and one trip failures. If DTC P1899 is
present, repair P/N switch code first. See DTC P1899: P/N SWITCH STUCK
IN PARK OR ON GEAR. If DTC P1899 is not present, go to next step.
3) Raise and support vehicle. Using scan tool, erase DTCs.
See CLEARING DIAGNOSTIC TROUBLE CODES. Start engine. Place engine in
1st gear. Using scan tool, read output speed sensor. Release brake and
let wheels roll, keeping speed below 15 MPH. If scan tool shows 60 RPM
or less, go to step 6). If scan tool shows greater than 60 RPM, go to
next step.
4) While monitoring output speed sensor, wiggle harness
between output speed sensor and PCM. If reading dropped towards zero
while wiggling harness, repair intermittent short or open in harness.
If reading does not drop towards zero while wiggling harness, go to
next step.
5) Using scan tool, erase DTCs. See CLEARING DIAGNOSTIC
TROUBLE CODES. Road test vehicle. If code returns, there are no other
potential causes. Replace PCM. If code does not return, testing is
complete.
6) Turn ignition off. Disconnect PCM and output speed sensor
harness connectors and inspect for damage. Repair as necessary. If no
Page 235 of 1691

problem is found, measure resistance between output speed sensor
terminals. If resistance is 300-1200 ohms, go to next step. If
resistance is not as specified, replace output speed sensor.
7) Reconnect output speed sensor. Measure resistance between
ground and output speed sensor ground circuit at PCM harness
connector. If resistance is greater than 5 ohms, go to next step. If
resistance is not as specified, repair output speed sensor ground
circuit for a short to ground.
8) Measure resistance between ground and output speed sensor
signal circuit at PCM harness connector. If resistance is less than 5
ohms, repair output speed sensor signal circuit for a short to ground.
If resistance is not as specified, go to next step.
9) Measure resistance between output speed sensor signal
circuit and ground circuit at PCM harness connector. If resistance is
300-1200 ohms, replace PCM. If resistance is not as specified, go to
next step.
10) Disconnect output speed sensor harness connector. Measure
resistance of output speed sensor signal circuit between output speed
sensor harness connector and PCM harness connector. If resistance is
greater than 5 ohms, repair open in output speed sensor signal
circuit. If resistance is not as specified, repair open in output
speed sensor ground circuit.
11) Turn ignition on. Measure voltage between ground and
speed sensor ground circuit at PCM harness connector. Place gearshift
lever in each gear position and record voltage at each position. If
voltage is greater than one volt in any gear position, repair speed
sensor ground circuit for a short to power. If voltage is not as
specified, go to next step.
12) Raise and support vehicle. Start engine. Place gearshift
lever in "OD" position. Release brakes and allow wheels to rotate.
Using scan tool, monitor output speed sensor. While monitoring output
speed sensor, wiggle harness between output speed sensor and PCM. If
reading dropped towards zero while wiggling harness, repair
intermittent short or open in harness. If reading does not drop
towards zero while wiggling harness, problem is intermittent. See
INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is
complete.
DTC P0740: TORQ CONV CLU, NO RPM DROP AT LOCKUP
Circuit Description
Circuit is monitored continuously while key is on, and gear
selector is not in Park or Neutral. Code sets if Torque Converter
Clutch (TCC) does not achieve desired drop in RPM when TCC solenoid is\
near maximum duty cycle. A bad test 3 consecutive times is required to
set code.
Possible Causes
* Misfire trouble code set.
* Vehicle stalls (faulty TCC solenoid).
* TCC shaft seal/seal defective.
* Transmission fluid contaminated.
* TCC solenoid wiring harness defective.
* TCC defective.
* TCC hydraulic circuit damaged.
Diagnostic Procedure
1) Using scan tool, read DTCs. On all bodies except AB and WJ
bodies, go to next step. On AB and WJ bodies, if DTC SPECIFIC GOOD
TRIPS counter is not displayed or displayed count is not "0", go to
step 10). If DTC SPECIFIC GOOD TRIPS counter is displayed and
displayed count is "0", indicating DTC still exists, go to next step.