²Proper transmit/receive messages are occurring
on the PCI bus.
²Ignition key switch is in the RUN position.
Range shiftswill be allowed only if all of the fol-
lowing conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²A change in the Selector Switch state indicating
a range shift has been requested.
²Transmission in NEUTRAL signal must be rec-
ognized for at least 1.5 seconds 100 msec. (Auto-
matic transmissions only)
²Proper transmit/receive messages are occurring
on the PCI bus.
²Clutch signal is recognized for 500 msec 50
msec (Manual transmissions only).
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).
²Ignition key switch is in the RUN position.
²A valid mode sensor signal is being sensed by
the TCCM.
Ashift into transfer case Neutralwill be
allowed only if all of the following conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²The recessed Neutral Selection switch has been
depressed continuously for 4.0 seconds 100 msec
while all shift conditions have been continuously met.
²Transmission in NEUTRAL signal recognized
from the bus. (Automatic transmissions only)
²Clutch signal is recognized from the bus (Man-
ual transmissions only).
²Proper message transmissions/receptions are
occurring on the PCI bus.
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).
²Ignition key switch is in the RUN position,
engine off.
²Foot Brake is applied.
²A valid mode sensor signal is being sensed by
the TCCM.
Ashift out of transfer case Neutralwill be
allowed only if all of the following conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²The recessed Neutral Selection switch has been
depressed continuously for 1.0 seconds 100 msec
while all shift conditions have been continuously met.
²Transmission in NEUTRAL signal recognized
from the bus.(Automatic transmissions only)
²Clutch signal is recognized from the bus (Man-
ual transmissions only).
²Proper message transmissions/receptions are
occurring on the PCI bus.
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).²Ignition key switch is in the RUN position.
²Foot Brake is applied.
²A valid mode sensor signal is being sensed by
the TCCM.
SHIFT SEQUENCES
Once all the driver controllable conditions for the
requested shift have been met, the TCCM begins a
shift timer with a maximum duration of 1 second per
'D' channel transition. If the shift timer expires
before the TCCM recognizes to correct mode sensor
code, the shift is considered to have been blocked.
The blocked shift will increment the blocked shift
counter by one. The TCCM strategy for handling
blocked shifts will be described later. The process the
TCCM performs for the various shifts will be
described first.
RANGE AND MODE SHIFTS
The process for performing all the range and mode
shifts are the same. The following steps describe the
process.
²Allow time for Selector Switch debounce; 250
msec 50 msec.
²Extinguish the source gear's LED while flashing
desired transfer case position's LED.
²Engage the shift motor for a maximum of 1 sec-
ond 100 msec per 'D' channel transition in the des-
tination gear's direction while monitoring the mode
sensor channel transitions.
²Disengage the shift motor when the correct
mode sensor code is recognized.
²Solidly illuminate the selected gear's LED.
²Transmit a bus message that the transfer case
shift is complete.
²If the desired mode sensor code is not received
after the shift timer expires (ie. a blocked or other
condition exists), stop driving the motor and wait for
200 msec 50 msec. The shift motor is then reversed
in the direction back toward the source gear for up to
1.0 seconds 100 msec. per 'D' channel. The TCCM
waits for 2.0 seconds 50 msec. and repeats the
attempt to shift to the desired position.
The exception to the preceding sequence is when a
shift from 4L to 2WD/AWD is requested. If 2WD/
AWD is requested from the 4L position, the transfer
case is first driven to the 4H position. If the 4H posi-
tion is reached, the transfer case is then driven back
to the 2WD/AWD position and the shift is considered
complete. If the transfer case does not reach any the
4H position, but is in the 2WD/AWD 'D' channel, or
the 2WD/AWD between gear position on the 4H side
of 2WD/AWD, the shift is also considered complete.
DRELECTRONIC CONTROL MODULES 8E - 17
TRANSFER CASE CONTROL MODULE (Continued)
SHIFT REVERSAL TARGETS
If the shift timer expires (1 second per 'D' channel)
and the transfer case has not reached the desired
position, all shifts will attempt to return to their
original position with the exceptions of:
²If the intended shift is going to the High rail
from Low and can't make it, but it can make the
2WD/AWD position, the motor stops at that position.
The TCCM will not attempt to cross back over NEU-
TRAL if it does not have to. This means that there
was a block on the first attempt to go to 4H and the
transfer case has made it through NEUTRAL to a
known good position, then the motor will go back
only to the 2WD/4WD position and execute the
remainder of the attempts from there.
²For shifts out of NEUTRAL, any time a shift is
commanded out of NEUTRAL, the system needs to
get out. The TCCM should never go to NEUTRAL
unless the driver is commanding it and all required
conditions are being met
ENCODER DRIFT CORRECTION
Whenever a shift is completed, the TCCM stores
the position in memory as the transfer case's
intended position. The TCCM continuously monitors
the mode sensor and if the mode sensor drifts toward
into a NEUTRAL region sensor position for 2.0 sec-
onds, the TCCM will perform a motor drive to correct
the drift. The transfer case will be driven toward the
intended position for 1.0 seconds 100 msec. The
TCCM will wait for 2.0 seconds 50 msec. and repeat
the attempt to shift to the desired position. This will
continue until the intended position is reached.
SHIFT MOTOR BRAKING
Two modes of shift motor braking are employed to
improve shift performance, static and dynamic. Static
shift motor braking is utilized under the following
conditions:
²Whenever the transfer case is in the 2WD/AWD
or 4L 'D' channel position.²Whenever an invalid mode sensor code is
present.
Static motor braking is achieved by applying +12V
on both shift motor wires.
NOTE: Static Shift Motor Braking is independent of
ignition key position.
SHIFT ATTEMPT LIMIT
To protect the transfer case system, the TCCM will
impose a limit on the number of shifts that can occur
over a calibrated time period. The system will moni-
tor the number of 'D' channel segment transitions
that occur in any 30 second time period. If the num-
ber of segment transitions is 30 or greater, the sys-
tem will go into a default mode. The default mode of
operation for shifting is that the number of allowed
'D' channel transitions permitted to occur will be 3
over each 15 second 100 msec calibrated window of
time. After 5 minutes 100 msec, the motor can be
assumed to have cooled down and the system will
revert to normal operation. The following rules also
apply to the shift limit:
²The attempt limit will not prevent shifts coming
out of NEUTRAL, they will be allowed regardless of
the counter/timer.
²Any shift that is in progress when the counter
reaches a maximum count in time will be allowed to
complete before the default mode is entered. D-chan-
nel transitions during this period will not be counted
towards the default mode limit.
²A block, regardless of the direction, whether
towards destination or back towards reversal target
(shift timer expiring), will count as a value of 2 tran-
sitions towards the 30 segment transitions to go into
default mode as defined above. Current attempt limit
values are 30 transitions in 30 seconds and default
mode values are 3 transitions every 15 seconds for 5
minutes.
DRELECTRONIC CONTROL MODULES 8E - 19
TRANSFER CASE CONTROL MODULE (Continued)
TRANSMISSION CONTROL
MODULE
DESCRIPTION
The Transmission Control Module (TCM) (Fig. 9)
may be sub-module within the Powertrain Control
Module (PCM), Engine Control Module (ECM - Diesel
only) (Fig. 10), or a standalone module, depending on
the vehicle engine. The PCM, and TCM when
equipped, is located at the right rear of the engine
compartment, near the right inner fender.
OPERATION
The Transmission Control Module (TCM) controls
all electronic operations of the transmission. The
TCM receives information regarding vehicle opera-
tion from both direct and indirect inputs, and selects
the operational mode of the transmission. Direct
inputs are hardwired to, and used specifically by the
TCM. Indirect inputs are shared with the TCM via
the vehicle communication bus.
Some examples ofdirect inputsto the TCM are:
²Battery (B+) voltage
²Ignition ªONº voltage
²Transmission Control Relay (Switched B+)
²Throttle Position Sensor
²Crankshaft Position Sensor
²Transmission Range Sensor
²Pressure Switches
²Transmission Temperature Sensor
²Input Shaft Speed Sensor
²Output Shaft Speed Sensor
²Line Pressure Sensor
Some examples ofindirect inputsto the TCM
are:²Engine/Body Identification
²Manifold Pressure
²Target Idle
²Torque Reduction Confirmation
²Engine Coolant Temperature
²Ambient/Battery Temperature
²DRBIIItScan Tool Communication
Based on the information received from these var-
ious inputs, the TCM determines the appropriate
shift schedule and shift points, depending on the
present operating conditions and driver demand.
This is possible through the control of various direct
and indirect outputs.
Some examples of TCMdirect outputsare:
²Transmission Control Relay
²Solenoids
²Torque Reduction Request
Some examples of TCMindirect outputsare:
²Transmission Temperature (to PCM)
²PRNDL Position (to BCM)
In addition to monitoring inputs and controlling
outputs, the TCM has other important responsibili-
ties and functions:
²Storing and maintaining Clutch Volume Indexes
(CVI)
²Storing and selecting appropriate Shift Sched-
ules
²System self-diagnostics
Fig. 9 PCM/TCM Location
1 - RIGHT FENDER
2 - TRANSMISSION CONTROL MODULE
3 - POWERTRAIN CONTROL MODULE
Fig. 10 Diesel ECM
1 - ENGINE CONTROL MODULE (ECM)
2 - ECM MOUNTING BOLT
3 - 50-WAY CONNECTOR
4 - SUPPORT PLATE
5 - 60-WAY CONNECTOR
8E - 20 ELECTRONIC CONTROL MODULESDR
STANDARD PROCEDURE
STANDARD PROCEDURE - TCM QUICK LEARN
The quick learn procedure requires the use of the
DRBtscan tool.
This program allows the electronic transmission
system to recalibrate itself. This will provide the
proper transmission operation. The quick learn pro-
cedure should be performed if any of the following
procedures are performed:
²Transmission Assembly Replacement
²Transmission Control Module Replacement
²Solenoid Pack Replacement
²Clutch Plate and/or Seal Replacement
²Valve Body Replacement or Recondition
To perform the Quick Learn Procedure, the follow-
ing conditions must be met:
²The brakes must be applied
²The engine speed must be above 500 rpm
²The throttle angle (TPS) must be less than 3
degrees
²The shift lever position must stay in PARK until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the DRBt
indicates the procedure is complete
²The calculated oil temperature must be above
60É and below 200É
STANDARD PROCEDURE - DRIVE LEARN
When a transmission is repaired and a Quick
Learn procedure has been performed on the Trans-
mission Control Module (TCM), the following Drive
Learn procedure can be performed to fine tune any
shifts which are particularly objectionable.
NOTE: It is not necessary to perform the complete
Drive Learn procedure every time the TCM is Quick
Learned. Perform only the portions which target the
objectionable shift.
LEARN A SMOOTH 1ST NEUTRAL TO DRIVE SHIFT
Perform this procedure only if the complaint is for
a delayed or harsh shift the first time the transmis-
sion is put into gear after the vehicle is allowed to
set with the engine not running for at least 10 min-
utes. Use the following steps to have the TCM learn
the 1st N-D UD CVI.
NOTE: The transmission oil temperature must be
between 80 - 110ÉF (27 - 43ÉC).
(1) Start the engine only when the engine and
ignition have been off for at least ten (10) minutes.
(2) With the vehicle at a stop and the service
brake applied, record the 1st N-D UD CVI while per-forming a Neutral to Drive shift. The 1st N-D UD
CVI accounts for air entrapment in the UD clutch
that may occur after the engine has been off for a
period of time.
(3) Repeat Step 1 and Step 2 until the recorded 1st
N-D UD CVI value stabilizes.
NOTE: It is important that this procedure be per-
formed when the transmission temperature is
between 80 - 110ÉF (27 - 43ÉC). If this procedure
takes too long to complete fully for the allowed
transmission oil temperature, the vehicle may be
returned to the customer with an explanation that
the shift will improve daily during normal vehicle
usage. The TCM also learns at higher oil tempera-
tures, but these values (line pressure correction
values) are not available for viewing on the DRBT
III.
LEARN A SMOOTH NEUTRAL TO DRIVE GARAGE
SHIFT
Perform this procedure if the complaint is for a
delayed or harsh shift when the transmission is put
into gear after the vehicle has had its first shift. Use
the following steps to have the TCM learn the Norm
N-D UD CVI.
NOTE: The transmission oil temperature must be
between 80 - 110ÉF (27 - 43ÉC) to learn the UD CVI.
Additional learning occurs at temperatures as low
as 0ÉF and as high as 200ÉF. This procedure may be
performed at any temperature that experiences poor
shift quality. Although the UD CVI may not change,
shift quality should improve.
(1) Start the vehicle engine and shift to drive.
(2) Move the vehicle forward to a speed of at least
16 km/h (10 MPH) and come to a stop. This ensures
no air is present in the UD hydraulic circuit.
(3) Perform repeated N-D shifts at a stop while
pausing in Neutral for at least 2-3 seconds and mon-
itor Norm N-D UD CVI volume until the value stabi-
lizes. The value will change during the N-D shift.
This is normal since the UD value is different for the
N-D shift then the normal value shown which is used
for 4-3 coastdown and kickdowns. Perform repeated
shifts in this temperature range until the Norm N-D
UD CVI value stabilizes and the N-D shifts become
smooth.
LEARN THE 1ST 2-3 SHIFT AFTER A RESTART OR
SHIFT TO REVERSE
Use the following steps to have the TCM learn the
1st 2-3 shift OD CVI.
DRELECTRONIC CONTROL MODULES 8E - 23
TRANSMISSION CONTROL MODULE (Continued)
(1) Before measuring the open-circuit voltage, the
surface charge must be removed from the battery.
Turn on the headlamps for fifteen seconds, then
allow up to five minutes for the battery voltage to
stabilize.
(2) Disconnect and isolate both battery cables, neg-
ative cable first.
(3) Using a voltmeter connected to the battery
posts (see the instructions provided by the manufac-
turer of the voltmeter), measure the open-circuit volt-
age (Fig. 8).
See the Open-Circuit Voltage Table. This voltage
reading will indicate the battery state-of-charge, but
will not reveal its cranking capacity. If a battery has
an open-circuit voltage reading of 12.4 volts or
greater, it may be load tested to reveal its cranking
capacity (Refer to 8 - ELECTRICAL/BATTERY SYS-
TEM/BATTERY - STANDARD PROCEDURE).
OPEN CIRCUIT VOLTAGE TABLE
Open Circuit Voltage Charge Percentage
11.7 volts or less 0%
12.0 volts 25%
12.2 volts 50%
12.4 volts 75%
12.6 volts or more 100%
STANDARD PROCEDURE - IGNITION-OFF
DRAW TEST
The term Ignition-Off Draw (IOD) identifies a nor-
mal condition where power is being drained from the
battery with the ignition switch in the Off position. A
normal vehicle electrical system will draw from five
to thirty-five milliamperes (0.005 to 0.035 ampere)
with the ignition switch in the Off position, and all
non-ignition controlled circuits in proper working
order. Up to thirty-five milliamperes are needed to
enable the memory functions for the Powertrain Con-
trol Module (PCM), digital clock, electronically tuned
radio, and other modules which may vary with the
vehicle equipment.
A vehicle that has not been operated for approxi-
mately twenty days, may discharge the battery to an
inadequate level. When a vehicle will not be used for
twenty days or more (stored), remove the IOD fuse
from the Integrated Power Module (IPM). This will
reduce battery discharging.
Excessive IOD can be caused by:
²Electrical items left on.
²Faulty or improperly adjusted switches.
²Faulty or shorted electronic modules and compo-
nents.
²An internally shorted generator.
²Intermittent shorts in the wiring.
If the IOD is over thirty-five milliamperes, the
problem must be found and corrected before replac-
ing a battery. In most cases, the battery can be
charged and returned to service after the excessive
IOD condition has been corrected.
(1) Verify that all electrical accessories are off.
Turn off all lamps, remove the ignition key, and close
all doors. If the vehicle is equipped with an illumi-
nated entry system or an electronically tuned radio,
allow the electronic timer function of these systems
to automatically shut off (time out). This may take
up to three minutes. See the Electronic Module Igni-
tion-Off Draw Table for more information.
Fig. 8 Testing Open-Circuit Voltage - Typical
DRBATTERY SYSTEM 8F - 11
BATTERY (Continued)
ELECTRONIC MODULE IGNITION-OFF DRAW (IOD) TABLE
ModuleTime Out?
(If Yes, Interval And Wake-Up Input)IODIOD After Time
Out
Radio No1to3
milliamperesN/A
Audio Power
AmplifierNoup to 1
milliampereN/A
Powertrain Control
Module (PCM)No 0.95 milliampere N/A
ElectroMechanical
Instrument Cluster
(EMIC)No 0.44 milliampere N/A
Combination Flasher No 0.08 milliampere N/A
(2) Determine that the underhood lamp is operat-
ing properly, then disconnect the lamp wire harness
connector or remove the lamp bulb.
(3) Disconnect the battery negative cable.
(4) Set an electronic digital multi-meter to its
highest amperage scale. Connect the multi-meter
between the disconnected battery negative cable ter-
minal clamp and the battery negative terminal post.
Make sure that the doors remain closed so that the
illuminated entry system is not activated. The multi-
meter amperage reading may remain high for up to
three minutes, or may not give any reading at all
while set in the highest amperage scale, depending
upon the electrical equipment in the vehicle. The
multi-meter leads must be securely clamped to the
battery negative cable terminal clamp and the bat-
tery negative terminal post. If continuity between the
battery negative terminal post and the negative cable
terminal clamp is lost during any part of the IOD
test, the electronic timer function will be activated
and all of the tests will have to be repeated.
(5) After about three minutes, the high-amperage
IOD reading on the multi-meter should become very
low or nonexistent, depending upon the electrical
equipment in the vehicle. If the amperage reading
remains high, remove and replace each fuse or circuit
breaker in the Integrated Power Module (IPM), one
at a time until the amperage reading becomes very
low, or nonexistent. Refer to the appropriate wiring
information in this service manual for complete Inte-
grated Power Module fuse, circuit breaker, and cir-
cuit identification. This will isolate each circuit and
identify the circuit that is the source of the high-am-
perage IOD. If the amperage reading remains high
after removing and replacing each fuse and circuit
breaker, disconnect the wire harness from the gener-
ator. If the amperage reading now becomes very low
or nonexistent, refer to Charging System for the
proper charging system diagnosis and testing proce-
dures. After the high-amperage IOD has been cor-rected, switch the multi-meter to progressively lower
amperage scales and, if necessary, repeat the fuse
and circuit breaker remove-and-replace process to
identify and correct all sources of excessive IOD. It is
now safe to select the lowest milliampere scale of the
multi-meter to check the low-amperage IOD.
CAUTION: Do not open any doors, or turn on any
electrical accessories with the lowest milliampere
scale selected, or the multi-meter may be damaged.
(6) Observe the multi-meter reading. The low-am-
perage IOD should not exceed thirty-five milliam-
peres (0.035 ampere). If the current draw exceeds
thirty-five milliamperes, isolate each circuit using the
fuse and circuit breaker remove-and-replace process
in Step 5. The multi-meter reading will drop to
within the acceptable limit when the source of the
excessive current draw is disconnected. Repair this
circuit as required; whether a wiring short, incorrect
switch adjustment, or a component failure is at fault.
STANDARD PROCEDURE - USING MICRO 420
BATTERY TESTER
Always use the Micro 420 Instruction Manual that
was supplied with the tester as a reference. If the
Instruction Manual is not available the following pro-
cedure can be used:
WARNING: ALWAYS WEAR APPROPRIATE EYE
PROTECTION AND USE EXTREME CAUTION WHEN
WORKING WITH BATTERIES.
BATTERY TESTING
(1) If testing the battery OUT-OF-VEHICLE, clean
the battery terminals with a wire brush before test-
ing. If the battery is equipped with side post termi-
nals, install and tighten the supplied lead terminal
stud adapters. Do not use steel bolts. Failure to prop-
8F - 12 BATTERY SYSTEMDR
BATTERY (Continued)
CHARGING
TABLE OF CONTENTS
page page
CHARGING
DESCRIPTION.........................19
OPERATION...........................19
DIAGNOSIS AND TESTING - CHARGING
SYSTEM............................19
SPECIFICATIONS
GENERATOR RATINGS.................20
SPECIFICATIONS - TORQUE - GENERATOR
/ CHARGING SYSTEM..................20
BATTERY TEMPERATURE SENSOR
DESCRIPTION.........................21OPERATION...........................21
REMOVAL.............................21
INSTALLATION.........................21
GENERATOR
DESCRIPTION.........................21
OPERATION...........................21
REMOVAL.............................22
INSTALLATION.........................24
VOLTAGE REGULATOR
DESCRIPTION.........................25
OPERATION...........................25
CHARGING
DESCRIPTION
The charging system consists of:
²Generator
²Electronic Voltage Regulator (EVR) circuitry
within the Powertrain Control Module (PCM). Elec-
tronic Control Module (ECM) for diesel engines.
²Ignition switch
²Battery (refer to 8, Battery for information)
²Battery temperature sensor
²Check Gauges Lamp (if equipped)
²Voltmeter (refer to 8, Instrument Panel and
Gauges for information)
²Wiring harness and connections (refer to 8, Wir-
ing Diagrams for information)
OPERATION
The charging system is turned on and off with the
ignition switch. The system is on when the engine is
running and the ASD relay is energized. When the
ASD relay is on, voltage is supplied to the ASD relay
sense circuit at the PCM (ECM Diesel). This voltage
is connected through the PCM (ECM Diesel) and sup-
plied to one of the generator field terminals (Gen.
Source +) at the back of the generator.
The amount of direct current produced by the gen-
erator is controlled by the EVR (field control) cir-
cuitry contained within the PCM (ECM Diesel). This
circuitry is connected in series with the second rotor
field terminal and ground.
A battery temperature sensor, located in the bat-
tery tray housing, is used to sense battery tempera-
ture. This temperature data, along with data from
monitored line voltage, is used by the PCM (ECM
Diesel) to vary the battery charging rate. This isdone by cycling the ground path to control the
strength of the rotor magnetic field. The PCM then
compensates and regulates generator current output
accordingly.
All vehicles are equipped with On-Board Diagnos-
tics (OBD). All OBD-sensed systems, including EVR
(field control) circuitry, are monitored by the PCM
(ECM Diesel). Each monitored circuit is assigned a
Diagnostic Trouble Code (DTC). The PCM will store a
DTC in electronic memory for certain failures it
detects.
The Check Gauges Lamp (if equipped) monitors:
charging system voltage,engine coolant tempera-
ture and engine oil pressure. If an extreme condition
is indicated, the lamp will be illuminated. This is
done as reminder to check the three gauges. The sig-
nal to activate the lamp is sent via the CCD bus cir-
cuits. The lamp is located on the instrument panel.
Refer to 8, Instrument Panel and Gauges for addi-
tional information.
DIAGNOSIS AND TESTING - CHARGING
SYSTEM
The following procedures may be used to diagnose
the charging system if:
²the check gauges lamp (if equipped) is illumi-
nated with the engine running
²the voltmeter (if equipped) does not register
properly
²an undercharged or overcharged battery condi-
tion occurs.
Remember that an undercharged battery is often
caused by:
²accessories being left on with the engine not
running
DRCHARGING 8F - 19
²a faulty or improperly adjusted switch that
allows a lamp to stay on. Refer to Ignition-Off Draw
Test in 8, Battery for more information.
INSPECTION
The PCM (Powertrain Control Module), or ECM
(Diesel) monitors critical input and output circuits of
the charging system, making sure they are opera-
tional. A Diagnostic Trouble Code (DTC) is assigned
to each input and output circuit monitored by the
On-Board Diagnostic (OBD) system. Some charging
system circuits are checked continuously, and some
are checked only under certain conditions.
Refer to Diagnostic Trouble Codes in; Powertrain
Control Module; Electronic Control Modules for more
DTC information. This will include a complete list of
DTC's including DTC's for the charging system.
To perform a complete test of the charging system,
refer to the appropriate Powertrain Diagnostic Proce-
dures service manual and the DRBtscan tool. Per-
form the following inspections before attaching the
scan tool.
(1) Inspect the battery condition. Refer to 8, Bat-
tery for procedures.(2) Inspect condition of battery cable terminals,
battery posts, connections at engine block, starter
solenoid and relay. They should be clean and tight.
Repair as required.
(3) Inspect all fuses in both the fuseblock and
Power Distribution Center (PDC) for tightness in
receptacles. They should be properly installed and
tight. Repair or replace as required.
(4) Inspect generator mounting bolts for tightness.
Replace or tighten bolts if required. Refer to the Gen-
erator Removal/Installation section of this group for
torque specifications.
(5) Inspect generator drive belt condition and ten-
sion. Tighten or replace belt as required. Refer to
Belt Tension Specifications in 7, Cooling System.
(6) Inspect automatic belt tensioner (if equipped).
Refer to 7, Cooling System for information.
(7) Inspect generator electrical connections at gen-
erator field, battery output, and ground terminal (if
equipped). Also check generator ground wire connec-
tion at engine (if equipped). They should all be clean
and tight. Repair as required.
SPECIFICATIONS
GENERATOR RATINGS
TYPE PART NUMBER RATED SAE AMPS ENGINES
DENSO 56029700AA 136 3.7L / 4.7L
BOSCH 56041120AC 136 3.7L / 4.7L
DENSO 56028696AA 136 5.7L Gas/5.9L Diesel
BOSCH 56028699AA 136 5.7L Gas/5.9L Diesel
SPECIFICATIONS - TORQUE - GENERATOR /
CHARGING SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Generator Mounting Bolts
- 5.7L41 30 -
Generator Support
Bracket Bolt/Nuts - 5.7L41 30 -
Generator Upper Mounting
Bolt - 5.9L Diesel Engine41 30 -
Generator Vertical
Mounting Bolt - 3.7L / 4.7L
Engines55 40 -
Generator (long)
Horizontal Mounting Bolt -
3.7L / 4.7L Engines55 40 -
8F - 20 CHARGINGDR
CHARGING (Continued)