
A defective fuel injection pump, defective fuel tim-
ing solenoid or misadjusted mechanical pump timing
can cause starting problems or prevent the engine
from revving up. It can also cause:
²Engine surge at idle
²Rough idle (warm engine)
²Low power
²Excessive fuel consumption
²Poor performance
²Low power
²Black smoke from the exhaust
²Blue or white fog like exhaust
²Incorrect idle or maximum speed
The electronically controlled fuel pump has no
mechanical governor like older mechanically con-
trolled fuel pumps. Do not remove the top cover of
the fuel pump, or the screws fastening the wiring
pigtail to the side of the pump.The warranty of
the injection pump and the engine may be void
if those seals have been removed or tampered
with.
FUEL SUPPLY RESTRICTIONS
LOW±PRESSURE LINES
Restricted or Plugged supply lines or fuel filter can
cause a timing fault that will cause the PCM to oper-
ate the engine in a ªLimp Homeº mode. See the
introduction of the Fuel Injection System in this
group for more information on the Limp Home mode.
Fuel supply line restrictions can cause starting prob-
lems and prevent the engine from revving up. The
starting problems include; low power and blue or
white fog like exhaust. Test all fuel supply lines for
restrictions or blockage. Flush or replace as neces-
sary. Bleed the fuel system of air once a fuel supply
line has been replaced. Refer to the Air Bleed Proce-
dure section of this group for procedures.
HIGH±PRESSURE LINES
Restricted (kinked or bent) high±pressure lines can
cause starting problems, poor engine performance
and black smoke from exhaust.
Examine all high±pressure lines for any damage.
Each radius on each high±pressure line must be
smooth and free of any bends or kinks.
Replace damaged, restricted or leaking high±pres-
sure fuel lines with the correct replacement line.
CAUTION: The high±pressure fuel lines must be
clamped securely in place in the holders. The lines
cannot contact each other or other components. Do
not attempt to weld high±pressure fuel lines or to
repair lines that are damaged. Only use the recom-
mended lines when replacement of high±pressure
fuel line is necessary.
FUEL SHUTDOWN SOLENOID TEST
Since diesel fuel injection does not use spark plugs
to start combustion, the only way to stop the engine
is to cut off the fuel supply. This is done with the
Fuel Shutdown Solenoid. If the engine cranks, but
refuses to start, it may be caused by a defective fuel
shutdown solenoid.
The fuel shutdown solenoid is not controlled
or operated by the PCM.Voltage to operate the
solenoid is supplied from the ignition (key) switch.
NOTE: Although the fuel shutdown solenoid is not
operated by the PCM, if the Fuel Shutdown Solenoid
has been disconnected, and the key turned on, the
PCM will sense that the solenoid is not in the circuit,
and will switch to a ªLimp Homeº mode. After recon-
necting the solenoid, the PCM will have to be reset
by clearing the codes with the DRBIII scan tool, or
disconnecting the vehicle's battery for several min-
utes. The DRBIII scan tool is the preferred method
for resetting the PCM. Refer to the 1998 GS 2.5L Die-
sel Powertrain Diagnostic Manual for procedure.
The fuel shutdown (shut±off) solenoid is used to
electrically shut off the diesel fuel supply to the high-
±pressure fuel injection pump. The solenoid is
mounted to the rear of the injection pump (Fig. 23).
The solenoid controls starting and stopping of the
engine regardless of the position of the accelerator
pedal. When the ignition (key) switch is OFF, the sole-
noid is shut off and fuel flow is not allowed to the fuel
injection pump. When the key is placed in the ON or
Fig. 23 Fuel Shutdown Solenoid Location
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 13
DIAGNOSIS AND TESTING (Continued)

to Group 8W for wiring connector and circuitry infor-
mation. Repair the wire harness if an open circuit is
indicated.
(4) After tests are completed, connect electrical
connector to sensor.
GLOW PLUG TEST
Hard starting or a rough idle after starting may be
caused by one or more defective glow plugs. Before
testing the glow plugs, a test of the glow plug relay
should be performed. This will ensure that 12V+ is
available at the plugs when starting the engine.
Refer to the Glow Plug Relay Test for information.
For accurate test results, the glow plugs should be
removed from the engine. The plugs must be checked
when cold.Do not check the plugs if the engine
has recently been operated. If plugs are
checked when warm, incorrect amp gauge
readings will result.
Use Churchill Glow Plug Tester DX.900 or an
equivalent (Fig. 14) for the following tests. This
tester is equipped with 4 timer lamps.
(1) Remove the glow plugs from the engine. Refer
to Glow Plug Removal/Installation.
(2) Attach the red lead of the tester to the 12V+
(positive) side of the battery.
(3) Attach the black lead of the tester to the 12V±
(negative) side of the battery.
(4) Fit the glow plug into the top of the tester and
secure it with the spring loaded bar (Fig. 14).
(5) Attach the third lead wire of the tester to the
electrical terminal at the end of the glow plug.(6) When performing the test, the tester button
(Fig. 14) should be held continuously without release
for 20 seconds as indicated by the 4 timer lamps.
Each illuminated lamp represents a 5 second time
lapse.
(a) Press and hold the tester button (Fig. 14)
and note the amp gauge reading. The gauge read-
ing should indicate a momentary, initial current
draw (surge) of approximately 25 amps. After the
initial surge, the amp gauge reading should begin
to fall off. The glow plug tip should start to glow
an orange color after 5 seconds. If the tip did not
glow after 5 seconds, replace the glow plug. Before
discarding the glow plug, check the position of the
circuit breaker on the bottom of the plug tester. It
may have to be reset. Reset if necessary.
(b) Continue to hold the tester button while
observing the amp gauge and the 4 timer lamps.
When all 4 lamps are illuminated, indicating a 20
second time lapse, the amp gauge reading should
indicate a 9±12 amp current draw. If not, replace
the glow plug. Refer to Glow Plug Removal/Instal-
lation.
(7) Check each glow plug in this manner using one
20 second cycle. If the glow plug is to be retested, it
must first be allowed to cool to room temperature.
WARNING: THE GLOW PLUG WILL BECOME
EXTREMELY HOT (GLOWING) DURING THESE
TESTS. BURNS COULD RESULT IF IMPROPERLY
HANDLED. ALLOW THE GLOW PLUG TO COOL
BEFORE REMOVING FROM TESTER.
(8) Remove the glow plug from the tester.
GLOW PLUG RELAY TEST
The glow plug relay is located in the engine com-
partment on the left±inner fender (Fig. 15).
When the ignition (key) switch is placed in the ON
position, a signal is sent to the PCM relating current
engine coolant temperature. This signal is sent from
the engine coolant temperature sensor.
After receiving this signal, the PCM will deter-
mine if, when and for how long a period the glow
plug relay should be activated. This is done before,
during and after the engine is started. Whenever the
glow plug relay is activated, it will control the 12V+
100 amp circuit for the operation of the four glow
plugs.
The Glow Plug lamp is tied to this circuit. Lamp
operation is also controlled by the PCM.
With a cold engine, the glow plug relay and glow
plugs may be activated for a maximum time of 200
seconds. Refer to the Glow Plug Control chart for a
temperature/time comparison of glow plug relay oper-
ation.
Fig. 14 Typical Glow Plug Tester
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 51
DIAGNOSIS AND TESTING (Continued)

Inspect all valve springs for distortion and col-
lapsed coils. Inspect all valves and plugs for burrs,
nicks, and scores. Small nicks and scores may be
removed with crocus cloth, providing extreme care is
taken not to round off sharp edges. The sharpness of
these edges is vitally important. It prevents foreign
matter from lodging between valve and valve body.
This reduces the possibility of sticking. Inspect all
valves and plugs for freedom of operation in valve
body bores.
When bores, valves, and plugs are clean and dry,
the valves and plugs should fall freely in the bores.
The valve body bores do not change its dimensions
with use. Therefore, a valve body that was function-
ing properly when vehicle was new, will operate cor-
rectly if it is properly and thoroughly cleaned. There
is no need to replace valve body unless it is damaged
in handling.
ADJUSTMENTS
GEARSHIFT CABLE ADJUSTMENT
Lift and rotate the gearshift hand lever into the
park (P) gate position and remove the ignition key.
This confirms the shift lever is in the gated park (P)
position.
After confirming the park gate position, turn the
ignition switch. If the starter will operate, the park
gate position is correct. Move the shift lever into the
neutral (N) position. If the starter will operate in this
position, the linkage is properly adjusted. If the
starter fails to operate in either position, linkage
adjustment is required.
(1) Park the vehicle on level ground and set the
parking brake.
(2) Place the gearshift lever in park (P) gate posi-
tion and remove key.
(3) Loosen the cable adjustment screw at the tran-
saxle operating lever (Fig. 160).
(4) Pull the transaxle operating lever fully forward
to the park detent position.
(5) Release the park brake, then rock the vehicle
to assure it is in park lock. Reset the park brake.
(6) Tighten the cable adjustment screw to 8 N´m
(70 in. lbs.). Gearshift cable should now be properly
adjusted.
(7) Verify PRNDL indicator still displays the corre-
sponding gear completely. If not, readjustment of
PRNDL may be required.
(8) Check adjustment by using the preceding pro-
cedure.
THROTTLE PRESSURE LINKAGE ADJUSTMENT
The throttle pressure rod adjustment is very
important to proper transaxle operation. This adjust-
ment positions a valve which controls shift speed,shift quality, and part throttle downshift sensitivity.
If the setting is too short, early shifts and slippage
between shifts may occur. If the setting is too long,
shifts may be delayed and part throttle downshifts
may be very sensitive.
With engine at operating temperature, adjust idle
speed of engine using a tachometer. Refer to Group
14, Fuel System for idle speed Specifications and
adjustment.
ROD ADJUSTMENT PROCEDURE
(1) Perform transaxle throttle pressure adjustment
while engine is at normal operating temperature.
(2) Loosen adjustment swivel lock screw.
(3) To insure proper adjustment, swivel must be
free to slide along flat end of throttle rod. Disassem-
ble and clean or repair parts to assure free action, if
necessary.
(4) Hold transaxle throttle lever firmly toward
engine, against its internal stop. Tighten swivel lock
screw to 11 N´m (100 in. lbs.)
(5) The adjustment is finished and linkage back-
lash was automatically removed by the preload
spring.
(6) I
f lubrication is required see Group 0, Lubrica-
tion.
BAND ADJUSTMENT
KICKDOWN BAND (FRONT)
The kickdown band adjusting screw is located on
left side (top front) of the transaxle case.
(1) Loosen locknut and back off nut approximately
five turns. Test adjusting screw for free turning in
the transaxle case.
(2) Using wrench, tighten adjusting screw to 8
N´m (72 in. lbs.).
Fig. 160 Gearshift Cable Adjustment
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 51
CLEANING AND INSPECTION (Continued)

²The shift lever position must stay until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the DRBIII
indicates the procedure is complete
²The calculated oil temperature must be above
60É and below 200É
(1) Plug the DRBIII scan tool into the data link
connector. The connector is located under the instru-
ment panel.
(2) Go to the Transmission screen.
(3) Go to the Miscellaneous screen.
(4) Select Quick Learn Procedure. Follow the
instructions of the DRBIII to perform the Quick
Learn Procedure.
PINION FACTOR PROCEDURE
The vehicle speed readings for the speedometer are
taken from the output speed sensor. The TCM must
be calibrated to the different combinations of equip-
ment available. A procedure has been developed
called Pinion Factor. It allows the technician to set
the Transmission Control Module initial setting so
that the speedometer readings will be correct.
Failure to perform this procedure will cause a No
Speedometer Operation condition.
This procedure must be performed if the Transmis-
sion Control Module has been replaced.
To properly read or reset the Pinion Factor, it is
necessary to use a DRBIII scan tool. Perform the fol-
lowing steps with the DRBIII scan tool to read or
reset the Pinion Factor:
(1) Plug the DRBIII scan tool into the data link
connector located under the instrument panel.
(2) Select the Transmission menu.
(3) Select the Miscellaneous menu.
(4) Select Pinion Factor. Then follow the instruc-
tions on the DRBIII scan tool screen.
REMOVAL AND INSTALLATION
GEARSHIFT CABLE
REMOVAL
(1) Remove cable eyelet attachment from transaxle
operating lever pin (Fig. 6).
(2) Using pliers, squeeze ears of cable conduit
attachment at mounting bracket (Fig. 7) and push
through hole to remove (Fig. 8).
(3) Remove the under instrument panel silencer
(Fig. 9). Refer to Group 8E, Instrument Panel And
Gauges for more information.
(4) At the steering column attachment, remove the
cable eyelet attachment from the shift lever pin.(5) Using pliers, squeeze ears of cable attachment
at mounting bracket then push through hole to
remove.
(6) Unseat the dash grommet and remove the
cable from the vehicle.
INSTALLATION
(1) Install cable into steering column attachment
bracket. Verify conduit ears are fully engaged. Verify
cable does not interfere with brake pedal actuation.
(2) Attach cable eyelet fitting onto shift lever pin.
(3) Insert transaxle end of cable through dash
panel hole and fully seat grommet.
(4) Install instrument panel silencer. Verify gear-
shift cable is routed through the slot in the silencer.
CAUTION: Failure to route the cable properly at the
silencer may cause brake pedal interference.
(5) Attach transaxle end of cable to the mounting
bracket on the transaxle. Assure the conduit attach-
ment ears are fully seated.
Fig. 6 Gearshift Cable
Fig. 7 Grommet Clips
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 83
SERVICE PROCEDURES (Continued)

(6) Attach cable eyelet fitting onto the transaxle
operating lever.
(7) Complete adjustment using the gearshift cable
adjustment procedure.
ADJUSTMENT
Lift and rotate the gearshift hand lever into the
park (P) gate position and remove the ignition key.
This confirms the shift lever is in the gated park (P)
position.
After confirming the park gate position, turn the
ignition switch. If the starter will operate, the park
gate position is correct. Move the shift lever into the
neutral (N) position. If the starter will operate in this
position, the linkage is properly adjusted. If the
starter fails to operate in either position, linkage
adjustment is required.
(1) Park the vehicle on level ground and set the
parking brake.
(2) Place the gearshift lever in park (P) gate posi-
tion and remove key.(3) Loosen the cable adjustment screw at the tran-
saxle operating lever (Fig. 10).
(4) Pull the transaxle operating lever fully forward
to the park detent position.
(5) Release the park brake, then rock the vehicle
to assure it is in park lock. Reset the park brake.
(6) Tighten the cable adjustment screw to 8 N´m
(70 in. lbs.). Gearshift cable should now be properly
adjusted.
(7) Check adjustment by using the preceding pro-
cedure.
MANUAL VALVE LEVER (SHIFT LEVER)
REMOVAL
(1) Remove shift cable from lever (Fig. 11).
(2) Loosen the lever mounting bolt (Fig. 12). Do
not remove bolt (not necessary).
(3) Pull up on lever and remove.
INSTALLATION
(1) For installation, reverse removal procedure.
Fig. 8 Remove Cable From Bracket
Fig. 9 Instrument Panel Silencer
Fig. 10 Gearshift Cable
Fig. 11 Shift Cable
21 - 84 TRANSAXLE AND POWER TRANSFER UNITNS
REMOVAL AND INSTALLATION (Continued)

(11) Install the oil baffle. Install the proper shim
combination under the bearing cup.
(12) Install the differential bearing retainer. Seal
the retainer to the housing with MopartSilicone
Rubber Adhesive Sealant. Torque bolts to 28 N´m
(250 in. lbs.).
(13) Using Miller Special Tool L-4436-A and an
inch-pound torque wrench, check the turning torque
of the differential (Fig. 299). The turning torque
should be between 5-18 inch-pounds.
NOTE: If turning torque is too high install a .05mm
(.002 inch) thicker shim. If the turning torque is too
low, install a .05mm (.002 inch) thinner shim. Repeat
until 5-18 inch-pounds of turning torque is
obtained.
CLEANING AND INSPECTION
CLEANING VALVE BODY
Prior to removing any transaxle parts, plug all
openings and clean unit, preferably by steam. Clean-
liness through entire disassembly and assembly can-
not be overemphasized. When disassembling, each
part should be washed in a suitable solvent, then
dried by compressed air.Do not wipe parts with
shop towels.All mating surfaces in the transaxles
are accurately machined; therefore, careful handling
of all parts must be exercised to avoid nicks or burrs.
NOTE: Tag all springs, as they are removed, for
reassembly identification.
ADJUSTMENTS
GEARSHIFT CABLE ADJUSTMENT
Lift and rotate the gearshift hand lever into the
park (P) gate position and remove the ignition key.This confirms the shift lever is in the gated park (P)
position.
After confirming the park gate position, turn the
ignition switch. If the starter will operate, the park
gate position is correct. Move the shift lever into the
neutral (N) position. If the starter will operate in this
position, the linkage is properly adjusted. If the
starter fails to operate in either position, linkage
adjustment is required.
(1) Park the vehicle on level ground and set the
parking brake.
(2) Place the gearshift lever in park (P) gate posi-
tion and remove key.
(3) Loosen the cable adjustment screw at the tran-
saxle operating lever (Fig. 300).
(4) Pull the transaxle operating lever fully forward
to the park detent position.
(5) Release the park brake, then rock the vehicle
to assure it is in park lock. Reset the park brake.
(6) Tighten the cable adjustment screw to 8 N´m
(70 in. lbs.). Gearshift cable should now be properly
adjusted.
(7) Check adjustment by using the preceding pro-
cedure.
Fig. 300 Gearshift Cable Adjustment
21 - 144 TRANSAXLE AND POWER TRANSFER UNITNS
DISASSEMBLY AND ASSEMBLY (Continued)

cranking. Whenever the Powertrain Control Module
(PCM) sets a Diagnostic Trouble Code (DTC) that
affects vehicle emissions, it illuminates the MIL. If a
problem is detected, the PCM sends a message over
the CCD Bus to the instrument cluster to illuminate
the lamp. The PCM illuminates the MIL only for
DTC's that affect vehicle emissions. The MIL stays
on continuously when the PCM has entered a
Limp-In mode or identified a failed emission compo-
nent or system. The MIL remains on until the DTC
is erased. Refer to the Diagnostic Trouble Code
charts in this group for emission related codes.
Also, the MIL either flashes or illuminates contin-
uously when the PCM detects active engine misfire.
Refer to Misfire Monitoring in this section.
Additionally, the PCM may reset (turn off) the MIL
when one of the following occur:
²PCM does not detect the malfunction for 3 con-
secutive trips (except misfire and fuel system moni-
tors).
²PCM does not detect a malfunction while per-
forming three successive engine misfire or fuel sys-
tem tests. The PCM performs these tests while the
engine is operating within6375 RPM of and within
10 % of the load of the operating condition at which
the malfunction was first detected.
STATE DISPLAY TEST MODE
The switch inputs to the Powertrain Control Mod-
ule (PCM) have two recognized states; HIGH and
LOW. For this reason, the PCM cannot recognize the
difference between a selected switch position versus
an open circuit, a short circuit, or a defective switch.
If the State Display screen shows the change from
HIGH to LOW or LOW to HIGH, assume the entire
switch circuit to the PCM functions properly. From
the state display screen, access either State Display
Inputs and Outputs or State Display Sensors.
STATE DISPLAY INPUTS AND OUTPUTS
Connect the DRB scan tool to the data link connec-
tor and access the State Display screen. Then access
Inputs and Outputs. The following list contains the
PCM system functions accessible through the Inputs
and Outputs screen.
Park/Neutral Switch
Speed Control Resume
Brake Switch
Speed Control On/Off
Speed Control Set
S/C Vent Solenoid
Actual S/C Vent Sol.
S/C Vacuum Solenoid
Actual S/C Vacuum Sol.
S/C Cancel
S/C Last Cutout
S/C Working Status
S/C Denied Status
A/C Clutch Relay
Actual A/C Clutch Relay
EGR Solenoid
Actual EGR Sol.
Automatic Shutdown Relay
Actual Automatic Shutdown Relay
Automatic Shutdown Relay Sense
Radiator Fan Control Module
Actual Radiator Fan Control Module
Duty Cycle EVAP Purge Solenoid
Actual EVAP Purge Sol.
Torque Converter Clutch Solenoid
Power Steering Switch
Closed Loop State
Current CMP Edge
Current CKP State
Current Sync State
Fuel Pump Relay
Actual Fuel Pump Relay
Ignition Sense (A21)
Malfunction Lamp
Limp-in Reason
STATE DISPLAY SENSORS
Connect the DRB scan tool to the vehicle and
access the State Display screen. Then access Sensor
Display. The following list contains the PCM system
functions accessible through the Sensor Display
screen.
Battery Temperature
Engine Coolant Temperature
Engine Coolant Temp Sensor
Throttle Position Volts
Minimum Throttle
Knock Sensor Volts
Battery Voltage
MAP Sensor Reading
Idle Air Control Motor Position
Fig. 1 Data Link (Diagnostic) Connector
25 - 2 EMISSION CONTROL SYSTEMSNS
DESCRIPTION AND OPERATION (Continued)