
CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
C315 DK GY At Driver Seat N/S
C316 BK At Passenger Seat N/S
C317 BK At Passenger Seat N/S
C319 BK Bottom Left of Left Door N/S
C320 Right Rear Door 43
C322 DK GY Left Rear of Frame 44, 46
C323 BK Left Side of Instrument Panel N/S
C327 BK Right Rear Fender 50, 51
C328 BK Left Rear Fender 50, 51, 52
Camshaft Position Sensor GY Right Front Side of Engine 3, 9
Capacitor Left Rear of Engine Compartment 4
Center High Mounted Stop
Lamp/Cargo LampBK Rear of Cab 49
Cigar Lighter Outlet NAT Rear of Cigar Lighter 32, 35, 36
Clearance Lamp No. 1 BK Left Roof 48
Clearance Lamp No. 2 BK Left-Center Roof 48
Clearance Lamp No. 3 BK Center Roof 48
Clearance Lamp No. 4 BK Right-Center Roof 48
Clearance Lamp No. 5 BK Right Roof 48
Clockspring C1 BK Steering Column 31
Clockspring C2 YL Steering Column 31
Clockspring C3 BK Steering Column N/S
Clockspring C4 BK Steering Column N/S
Clutch Interlock Brake Switch BK At Clutch Pedal 22, 24
Coil On Plug No.1 BK Left Top Side of Intake Manifold 6
Coil On Plug No.2 BK Right Top Side of Intake Manifold 3
Coil On Plug No.3 BK Left Top Side of Intake Manifold 6
Coil On Plug No.4 BK Right Top Side of Intake Manifold 3
Coil On Plug No.5 BK Left Top Side of Intake Manifold 5, 6
Coil On Plug No.6 BK Right Top Side of Intake Manifold 3
Coil On Plug No.7 BK Left Top Side of Intake Manifold 6
Coil On Plug No.8 BK Right Top Side of Intake Manifold 3
Compass/Mini-Trip Computer BK In Overhead Console N/S
Condenser Fan BK Near Condenser 23, 24
Controller Anti-Lock Brake C1 BK Left Fender Side Shield 22, 24, 25
Controller Anti-Lock Brake C2
(ABS)BK Left Fender Side Shield 22, 25
Crankshaft Position Sensor BK Right Rear of Engine Block 3, 9
Cylinder Lock Switch-Driver
(Premium)BK In Left Front Door 41
Cylinder Lock Switch-Passenger
(Premium)LT GY In Right Front Door N/S
Data Link Connector BK Left Bottom of Instrument Panel 35, 38
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 3
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Data Link Connector - Engine
(Diesel)BK Near T/O for Water In Fuel Sensor N/S
Dome Lamp BK Center of Headliner N/S
Door Ajar Switch-Driver (Base) BK Left Front Door 41
Door Ajar Switch-Left Rear (Base) BK Left Rear Door 43
Door Ajar Switch-Right Rear (Base) BK Right Rear Door 43
Door Lock Motor/Ajar Switch-Driver
(Except Base)BK Left Front Door 41
Door Lock Motor/Ajar Switch-Left
Rear (Except Base)BK Left Rear Door 43
Door Lock Motor/Ajar Switch-
PassengerBK Right Front Door 42
Door Lock Motor/Ajar Switch-Right
Rear (Except Base)BK Right Rear Door 43
Door Lock Switch-Passenger BL In Right Front Door 42
Driver Airbag Squib BK In Steering Column N/S
Driver Blend Door Actuator (Dual
Zone)BK Right Side of HVAC N/S
Driver Door Module C1 BL In Left Front Door 41
Driver Door Module C2 BL In Left Front Door 41
EGR Solenoid Right Front Engine 9
Electric Brake Provision Rear of Engine 22, 24
Engine Control Module C1 BK Left Engine 10
Engine Control Module C2 BK Left Engine 10
Engine Coolant Temperature
SensorBK Near Generator 6
Engine Oil Pressure Switch BK Lower Left Side of Engine 6, 9
Evap/Purge Solenoid BK Left Fender Side Shield 23, 25
Evaporator Temperature Sensor BK Right Side of HVAC N/S
Fog Lamp-Left WT Left Front Facia N/S
Fog Lamp-Right WT Right Front Facia N/S
Fuel Control Actuator (Diesel) BK Left Rear Engine N/S
Fuel Heater (Diesel) BK Left Side Engine 10
Fuel Injector No. 1 BK At Fuel Injector 6
Fuel Injector No. 2 BK At Fuel Injector 3
Fuel Injector No. 3 BK At Fuel Injector 6
Fuel Injector No. 4 BK At Fuel Injector 3
Fuel Injector No. 5 BK At Fuel Injector 6
Fuel Injector No. 6 BK At Fuel Injector 3
Fuel Injector No. 7 BK At Fuel Injector 6
Fuel Injector No. 8 BK At Fuel Injector 3
Fuel Pump Module LT GY At Fuel Tank 50
Fuel Pump Motor (Diesel) BK Left Side Engine 10
Generator BK Front of Engine 6, 9, 10
8W - 91 - 4 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Mode Door Actuator 2 BK Right Side of HVAC N/S
Multi-Function Switch BK On Steering Column 31
Natural Vacuum Leak Detection
AssemblyBK Rear of Transmission 18, 50
Output Speed Sensor DB Left Side of Transmission 11, 14, 15, 16
Overdrive Switch WT Center of Instrument Panel 35
Overhead Map/Reading Lamp
(Except Base)NAT Center of Headliner N/S
Oxygen Sensor 1/1 Upstream BK Left Front of Side of Transmission 15, 16, 17, 19
Oxygen Sensor 1/2 Downstream NAT Left Rear of Side of Transmission 15, 16, 17, 19
Oxygen Sensor 2/1 Upstream BK Right Front Side of Transmission 15, 17, 18
Oxygen Sensor 2/2 Downstream BK Right Rear Side of Transmission 15, 17, 18
Park Brake Switch At Park Brake 22, 24
Park/Turn Signal Lamp-Left Front BK At Lamp 23, 28, 29
Park/Turn Signal Lamp-Right Front BK At Lamp 1, 21, 26
Passenger Airbag On/Off Switch Right Side of Instrument Panel 33, 35, 39
Passenger Blend Door Actuator
(Dual Zone)BK Right Side of HVAC N/S
Passenger Lumbar Switch At Passenger Seat N/S
Power Mirror-Left BK At Mirror 41
Power Mirror-Right BK At Mirror 42
Power Outlet RD Center of Instrument Panel 35
Power Outlet-Console BK Center of Instrument Panel N/S
Power Seat Motor-Driver Front
VerticalRD At Driver Seat N/S
Power Seat Motor-Driver Horizontal BK At Driver Seat N/S
Power Seat Motor-Driver Rear
VerticalBK At Driver Seat N/S
Power Seat Switch-Driver BK At Driver Seat N/S
Power Seat Switch-Passenger BK At Passenger Seat N/S
Power Steering Pressure Switch BK Near Power Steering Pump 7
Power Window Circuit Breaker Under Instrument Panel 31, 35, 38
Power Window Motor-Driver BK In Driver Door at Motor 41
Power Window Motor-Left Rear BK In Door at Motor 43
Power Window Motor-Passenger BK In Passenger Door at Motor 42
Power Window Motor-Right Rear BK In Door at Motor 43
Power Window Switch-Left Rear BL In Door 43
Power Window Switch-Passenger Passenger Door 42
Power Window Switch-Right Rear BL In Door 43
Powertrain Control Module C1 BK Right Rear Engine Compartment 4, 8
Powertrain Control Module C2 WT Right Rear Engine Compartment 4, 8
Powertrain Control Module C3 GY Right Rear Engine Compartment 21
Powertrain Control Module C4 GN Right Rear Engine Compartment 4, 8
8W - 91 - 6 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
PTO Switch Near G107 N/S
Radio C1 (Base) GY Rear of Radio 35, 36
Radio C1 (Premium) BK Rear of Radio 36
Radio C2 (Premium) BK Rear of Radio 36
Radio Antenna - At Antenna Base 37
Radio Antenna Cable - Right Kick Panel 36, 37
Recirculation Door Actuator BK Right Side of HVAC N/S
Red Brake Warning Indicator
SwitchBK Near Master Cylinder 22, 25, 29
Remote Radio Switch-Left BK At Steering Wheel N/S
Remote Radio Switch-Right BK At Steering Wheel N/S
Seat Belt Pretensioner-Left YL Left B-Pillar 44, 46
Seat Belt Pretensioner-Right YL Right B-Pillar 45, 47
Seat Belt Switch-Driver DK GY Left B-Pillar N/S
Seat Belt Tension Reducer
(Standard Cab)YL Left B-Pillar 44
Seat Heater Interface Module GN Under Driver Seat N/S
Sentry Key Immobilizer Module BK On Steering Column 30
Side Marker - Left Front (Dual
Wheels)BK Front of Left Rear Fender 52
Side Marker - Left Rear (Dual
Wheels)BK Rear of Left Rear Fender 52
Side Marker - Right Front (Dual
Wheels)BK Front of Right Rear Fender 52
Side Marker - Right Rear (Dual
Wheels)BK Rear of Right Rear Fender 52
Speaker-Center Instrument Panel WT Center of Instrument Panel 35, 36
Speaker-Left Front Door WT In Left Front Door 41
Speaker-Left Instrument Panel BK Left Side of Instrument Panel 35, 38
Speaker-Left Rear (Standard Cab) WT In Lower Left B-Pillar 44
Speaker-Left Rear Door (Quad
Cab)WT In Left Rear Door 43
Speaker-Right Front Door WT In Right Front Door 42
Speaker-Right Instrument Panel BK Right Side of Instrument Panel 35, 39
Speaker-Right Rear (Standard
Cab)BK In Lower Right B-Pillar 45
Speaker-Right Rear Door (Quad
Cab)BK In Right Rear Door 43
Speed Control Servo BK Left Front Side of Engine
Compartment23, 25
Speed Control Switch - Left
(Except ETC)GN Steering Wheel N/S
Speed Control Switch - Right
(Except ETC)GN Steering Wheel N/S
Speed Control Switch-Left (ETC) WT At Steering Wheel N/S
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 7
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

This will ensure proper gear-to-shaft tighten-
ing.
(5) Clean pump gear and pump shaft at machined
tapers with an evaporative type cleaner such as
brake cleaner.
(6) Position injection pump to mounting flange on
gear housing while aligning injection pump shaft
through back of injection pump gear.
(7) After pump is positioned flat to mounting
flange, install 3 pump mounting nuts and tighten
finger tight only.Do not attempt a final tightening
at this time.Do not attempt to tighten (pull)
pump to gear housing using mounting nuts.
Damage to pump or gear cover may occur. The
pump must be positioned flat to its mounting
flange before attempting to tighten 3 mounting
nuts.
(8) To prevent damage or cracking of components,
install and tighten nuts in the following sequence:
(a) Install injection pump shaft washer and nut
to pump shaft. Tighten nutfinger tight only.
(b) Do preliminary (light) tightening of injection
pump shaft nut.
(c) Tighten 3 injection pump mounting nuts to
24 N´m (18 ft. lbs.).(d) Do a final tightening of pump shaft nut to
105 N´m (77 ft. lbs.).
(9) Install drive gear access cover (plate) using a
3/8º drive ratchet. Plate is threaded to timing gear
cover. Tighten to 8 N´m (71 in. lbs.) torque.
(10) Install fuel line (injection pump-to-pressure
limiting valve). Tighten bolts to 24 N´m (18 ft. lbs.)
torque.
(11) Install fuel line (injection pump-to-fuel rail).
(a) Tighten fitting at fuel pump to 37 N´m (27 ft.
lbs.) torque. Use a back-up wrench.
(b) Tighten fitting at fuel rail to 37 N´m (27 ft.
lbs.) torque.
(12) Install fuel line (injection pump-to-fuel filter
housing). Tighten to 24 N´m (18 ft. lbs.) torque.
(13) Connect Fuel Control Actuator (FCA) electri-
cal connector to rear of injection pump.
(14) Install intake manifold air intake tube (above
injection pump). Tighten clamps.
(15) Install accessory drive belt.
(16) Install cooling fan shroud.
(17) Install cooling fan assembly.
(18) Connect both negative battery cables to both
batteries.
(19) Check system for fuel or engine oil leaks.
Fig. 12 FUEL INJECTION PUMP REMOVAL/INSTALLATION
1 - PUMP DRIVE GEAR NUT
2 - WASHER
3 - PUMP DRIVE GEAR
4 - RUBBER O-RING
5 - FUEL INJECTION PUMP6 - PUMP MOUNTING NUTS (3)
7 - PUMP MOUNTING STUDS (3)
8 - O-RING MACHINED GROOVE
9 - FRONT TIMING GEAR HOUSING
14 - 56 FUEL DELIVERY - DIESELDR
FUEL INJECTION PUMP (Continued)

(3) Have helper start and run engine at 1600 rpm
for test.
(4)
Move transmission shift lever four detents rear-
ward from full forward position. This is Reverse range.
(5) Move transmission throttle lever fully forward
then fully rearward and note reading at Gauge
C-3293-SP.
(6) Pressure should be 145 - 175 psi (1000-1207
kPa) with throttle lever forward and increase to 230 -
280 psi (1586-1931 kPa) as lever is gradually moved
rearward.
Test Five - Governor Pressure
This test checks governor operation by measuring
governor pressure response to changes in vehicle
speed. It is usually not necessary to check governor
operation unless shift speeds are incorrect or if the
transmission will not downshift. The test should be
performed on the road or on a hoist that will allow
the rear wheels to rotate freely.
(1) Move 100 psi Test Gauge C-3292 to governor
pressure port.
(2) Move transmission shift lever two detents rear-
ward from full forward position. This is D range.
(3) Have helper start and run engine at curb idle
speed. Then firmly apply service brakes so wheels
will not rotate.
(4) Note governor pressure:
²
Governor pressure should be no more than 20.6
kPa (3 psi) at curb idle speed and wheels not rotating.
²If pressure exceeds 20.6 kPa (3 psi), a fault
exists in governor pressure control system.
(5) Release brakes, slowly increase engine speed,
and observe speedometer and pressure test gauge (do
not exceed 30 mph on speedometer). Governor pres-
sure should increase in proportion to vehicle speed.
Or approximately 6.89 kPa (1 psi) for every 1 mph.
(6) Governor pressure rise should be smooth and
drop back to no more than 20.6 kPa (3 psi), after
engine returns to curb idle and brakes are applied to
prevent wheels from rotating.
(7)
Compare results of pressure test with analysis
chart.
Test Six - Transmission In Overdrive Fourth Gear
This test checks line pressure at the overdrive
clutch in fourth gear range. Use 300 psi Test Gauge
C-3293-SP for this test. The test should be performed
on the road or on a chassis dyno.
(1)
Remove tachometer; it is not needed for this test.
(2) Move 300 psi Gauge to overdrive clutch pres-
sure test port. Then remove other gauge and reinstall
test port plug.
(3) Lower vehicle.
(4) Turn OD switch on.(5) Secure test gauge so it can be viewed from
drivers seat.
(6) Start engine and shift into D range.
(7) Increase vehicle speed gradually until 3-4 shift
occurs and note gauge pressure.
(8) Pressure should be 524-565 kPa (76-82 psi)
with closed throttle and increase to 690-896 kPa
(100-130 psi) at 1/2 to 3/4 throttle. Note that pres-
sure can increase to around 965 kPa (140 psi) at full
throttle.
(9) Return to shop or move vehicle off chassis
dyno.
PRESSURE TEST ANALYSIS CHART
TEST CONDITION INDICATION
Line pressure OK during
any one testPump and regulator
valve OK
Line pressure OK in R
but low in D, 2, 1Leakage in rear clutch
area (seal rings, clutch
seals)
Pressure low in D Fourth
Gear RangeOverdrive clutch piston
seal, or check ball
problem
Pressure OK in 1, 2 but
low in D3 and RLeakage in front clutch
area
Pressure OK in 2 but low
in R and 1Leakage in rear servo
Front servo pressure in 2 Leakage in servo; broken
servo ring or cracked
servo piston
Pressure low in all
positionsClogged filter, stuck
regulator valve, worn or
faulty pump, low oil level
Governor pressure too
high at idle speedGovernor pressure
solenoid valve system
fault. Refer to diagnostic
book.
Governor pressure low at
all mph figuresFaulty governor pressure
solenoid, transmission
control module, or
governor pressure
sensor
Lubrication pressure low
at all throttle positionsClogged fluid cooler or
lines, seal rings leaking,
worn pump bushings,
pump, clutch retainer, or
clogged filter.
Line pressure high Output shaft plugged,
sticky regulator valve
Line pressure low Sticky regulator valve,
clogged filter, worn pump
DRAUTOMATIC TRANSMISSION - 48RE 21 - 143
AUTOMATIC TRANSMISSION - 48RE (Continued)

BRAKE TRANSMISSION SHIFT
INTERLOCK SYSTEM
DESCRIPTION
The Brake Transmission Shifter Interlock (BTSI)
(Fig. 74), is a solenoid operated system. It consists of
a solenoid permanently mounted on the gearshift
cable.
OPERATION
The system locks the shifter into the PARK posi-
tion. The interlock system is engaged whenever the
ignition switch is in the LOCK or ACCESSORY posi-
tion. An additional electrically activated feature will
prevent shifting out of the PARK position unless the
brake pedal is depressed approximately one-half an
inch. A magnetic holding device in line with the park
lock cable is energized when the ignition is in the
RUN position. When the key is in the RUN position
and the brake pedal is depressed, the shifter is
unlocked and will move into any position. The inter-
lock system also prevents the ignition switch from
being turned to the LOCK or ACCESSORY position,
unless the shifter is fully locked into the PARK posi-
tion.
DIAGNOSIS AND TESTING - BRAKE
TRANSMISSION SHIFT INTERLOCK
(1) Verify that the key can only be removed in the
PARK position
(2) When the shift lever is in PARK And the shift
handle pushbutton is in the ªOUTº position, the igni-
tion key cylinder should rotate freely from OFF toLOCK. When the shifter is in any other gear or neu-
tral position, the ignition key cylinder should not
rotate to the LOCK position.
(3) Shifting out of PARK should not be possible
when the ignition key cylinder is in the OFF posi-
tion.
(4) Shifting out of PARK should not be possible
while applying normal pushbutton force and ignition
key cylinder is in the RUN or START positions
unless the foot brake pedal is depressed approxi-
mately 1/2 inch (12mm).
(5) Shifting out of PARK should not be possible
when the ignition key cylinder is in the ACCESSORY
or LOCK positions.
(6) Shifting between any gears, NEUTRAL or into
PARK may be done without depressing foot brake
pedal with ignition switch in RUN or START posi-
tions.
ADJUSTMENTS - BRAKE TRANSMISSION
SHIFT INTERLOCK
Correct cable adjustment is important to proper
interlock operation. The gearshift cable must be cor-
rectly adjusted in order to shift out of PARK.
ADJUSTMENT PROCEDURE
(1) Remove the steering column trim as necessary
for access to the brake transmission shift interlock.
(2) Shift the transmission into the PARK position.
(3) Pull upward on both the BTSI lock tab and the
gearshift cable lock tab (Fig. 75).
(4) Verify that the shift lever is in the PARK posi-
tion.
(5) Verify positive engagement of the transmission
park lock by attempting to rotate the propeller shaft.
The shaft will not rotate when the park lock is
engaged.
(6) Turn ignition switch to LOCK position.Be
sure ignition key cylinder is in the LOCK posi-
tion. Cable will not adjust correctly in any
other position.
(7) Ensure that the cable is free to self-adjust by
pushing cable rearward and releasing.
(8) Push the gearshift cable lock tab down until it
snaps in place.
(9) Locate the BTSI alignment hole in the bottom
of the BTSI mechanism between the BTSI lock tab
and the BTSI connector.
(10) Move the BTSI assembly up or down on the
gearshift cable until an appropriate size drill bit can
be inserted into the alignment hole and through the
assembly.
(11) Push the BTSI lock tab down until it snaps
into place and remove the drill bit.
(12) Install any steering column trim previously
removed.
Fig. 74 Brake Transmission Interlock Mechanism
1 - STEERING COLUMN
2 - GEARSHIFT CABLE
3 - GEARSHIFT CABLE LOCK TAB
4 - BTSI SOLENOID LOCK TAB
5 - BTSI CONNECTOR
21 - 196 AUTOMATIC TRANSMISSION - 48REDR

PROCEDURE TWO
(1) Start engine and apply parking brake.
(2) Shift the transmission into DRIVE for approxi-
mately 2 seconds.
(3) Shift the transmission into REVERSE for
approximately 2 seconds.
(4) Shift the transmission into PARK.
(5) Hook up DRBtscan tool and select engine.
(6) Select sensors.
(7) Read the transmission temperature value.
(8) Compare the fluid temperature value with the
chart.
(9) Adjust transmission fluid level shown on the
dipstick according to the chart (Fig. 88).
NOTE: After adding any fluid to the transmission,
wait a minimum of 2 minutes for the oil to fully
drain from the fill tube into the transmission before
rechecking the fluid level.
(10) Check transmission for leaks.
STANDARD PROCEDURE - FLUID AND FILTER
REPLACEMENT
For proper service intervals (Refer to LUBRICA-
TION & MAINTENANCE/MAINTENANCE SCHED-
ULES - DESCRIPTION). The service fluid fill after a
filter change is approximately 3.8 liters (4.0 quarts).
REMOVAL
(1) Hoist and support vehicle on safety stands.
(2) Place a large diameter shallow drain pan
beneath the transmission pan.
(3) Remove bolts holding front and sides of pan to
transmission (Fig. 89).
(4) Loosen bolts holding rear of pan to transmis-
sion.
Fig. 88 48RE Fluid Fill Graph
Fig. 89 Transmission Pan
1 - TRANSMISSION
2 - REUSABLE GASKET
3-PAN
DRAUTOMATIC TRANSMISSION - 48RE 21 - 203
FLUID AND FILTER (Continued)