Jeep Grand Cherokee WJ. Manual - part 948

second). If a fault is present the LED will remain on
or flashing for the complete ignition cycle.

If a fault is stored in SKIM memory which pre-

vents the system from operating properly, the PCM
will allow the engine to start and run (for 2 seconds)
up to six times. After the sixth attempt the PCM
will not allow the engine to start.

3.2.10

PROGRAMMING THE POWERTRAIN
CONTROL MODULE

IMPORTANT NOTE:

Before replacing the PCM for a failed driver,

control circuit or ground circuit, be sure to check the
related component/circuit integrity for failures not
detected due to a double fault in the circuit. Most
PCM driver/control circuit failures are caused by
internal failure to components (i.e. relay and sole-
noids) and short circuits (i.e. 12-volt pull-ups, driv-
ers and ground sensors). These failures are difficult
to detect when a double fault has occurred and only
one DTC has set.

NOTE: If the PCM and the SKIM are replaced at

the same time, program the VIN into the PCM first.
All vehicle keys will then need to be replaced and
programmed to the new SKIM.

The SKIS “Secret Key” is an ID code that is

unique to each SKIS. This code is programmed and
stored in the SKIM, PCM and transponder chip
(ignition key). When replacing the PCM it is neces-
sary to program the secret key into the PCM.

1. Turn the ignition on (transmission in park/

neutral).

2. Use the DRBIII

t and select “THEFT ALARM”,

“SKIM” then “MISCELLANEOUS”.

3. Select “PCM REPLACED”.

4. Enter secured access mode by entering the vehi-

cle four-digit PIN.

NOTE: If three attempts are made to enter the

secure access mode using an incorrect PIN, secured
access mode will be locked out for one hour. To exit
this lockout mode, turn the ignition to the RUN
position for one hour then enter the correct PIN.
(Ensure all accessories are turned off. Also, monitor
the battery state and connect a battery charger if
necessary).

5. Press “ENTER” to transfer the secret key (the

SKIM will send the secret key to the PCM).

3.2.11

PROGRAMMING THE SENTRY KEY
IMMOBILIZER MODULE

NOTE: If the PCM and the SKIM are replaced at

the same time, program the VIN into the PCM first.
All vehicle keys will then need to be replaced and
programmed to the new SKIM.

1. Turn the ignition on (transmission in park/

neutral).

2. Use the DRBIII

t and select “THEFT ALARM”,

“SKIM” then “MISCELLANEOUS”.

3. Select

“SKIM

MODULE

REPLACEMENT

(GASOLINE)”.

4. Program the vehicle four-digit PIN into the

SKIM.

5. Select “COUNTRY CODE” and enter the correct

country.

NOTE: Be sure to enter the correct country code.

If the incorrect country code is programmed into
SKIM, the SKIM must be replaced.

6. Select “UPDATE VIN” (the SKIM will learn the

VIN from the PCM).

7. Press “ENTER” to transfer the VIN (the PCM

will send the VIN to the SKIM).

8. The DRBIII

t will ask if you want to transfer the

secret key. Select “ENTER” to transfer secret key
from the PCM. This will ensure the current
vehicle ignition keys will still operate the SKIS
system.

3.2.12

PROGRAMMING THE IGNITION
KEYS TO THE SENTRY KEY
IMMOBILIZER MODULE

1. Turn the ignition on (transmission in park/

neutral).

2. Use the DRBIII

t and select “THEFT ALARM”,

“SKIM” and “MISCELLANEOUS”.

3. Select “PROGRAM IGNITION KEYS”.

4. Enter secured access mode by entering the vehi-

cle four-digit PIN.

NOTE: A maximum of eight keys can be learned

to each SKIM. Once a key is learned to a SKIM it
(the key) cannot be transferred to another vehicle.

If ignition key programming is unsuccessful, the

DRB will display one of the following messages:

Programming Not Attempted
The DRBIII

t attempts to read the programmed

key status and there are no keys programmed in the
SKIM memory.

Programming Key Failed
(Possible Used Key From Wrong Vehicle) - SKIM

is unable to program key due to one of the following:

– faulty ignition key transponder

– ignition key is programmed to another vehicle.

8 Keys Already Learned, Programming Not

Done

SKIM transponder ID memory is full

1. Obtain ignition keys to be programmed from

customer (8 keys maximum).

GENERAL INFORMATION

2. Using the DRBIII

t, erase all ignition keys by

selecting “MISCELLANEOUS” and “ERASE
ALL CURRENT IGN. KEYS”.

3. Program all ignition keys.

Learned Key In Ignition
Ignition key transponder ID is currently pro-

grammed in SKIM memory.

3.3

DIAGNOSTIC TROUBLE CODES

Each diagnostic trouble code is diagnosed by

following a specific testing procedure. The diagnos-
tic test procedures contain step-by-step instructions
for determining the cause of trouble codes as well as
no trouble code problems. It is not necessary to
perform all of the tests in this book to diagnose an
individual code.

Always begin by reading the diagnostic trouble

codes using the DRBIII

3.3.1

HARD CODE

A diagnostic trouble code that comes back within

one cycle of the ignition key is a ‘‘hard’’ code. This
means that the defect is there every time the
powertrain control module checks that circuit or
function. Procedures in this manual verify if the
trouble code is a hard code at the beginning of each
test. When it is not a hard code, an ‘‘intermittent’’
test must be performed.

Codes that are for Euro Stage III OBD monitors

will not set with just the ignition key on. Comparing
these to non-emission codes, they will seem like an
intermittent. These codes require a set of parame-
ters to be performed (The DRBIII

t pre-test screens

will help with this for MONITOR codes), this is
called a ‘‘TRIP’’. All Euro Stage III OBD DTCs will
be set after one or in some cases two trip failures,
and the MIL will be turned on. These codes require
three successful, no failures, TRIPS to extinguish
the MIL, followed by 40 warm-up cycles to erase the
code. For further explanation of TRIPS, Pre-test
screens, Warm-up cycles, and the use of the DRBI-
II

t, refer to the On Board Diagnostic training

booklet #81-699-97094.

3.3.2

INTERMITTENT CODE

A diagnostic trouble code that is not there every

time the PCM checks the circuit is an ‘‘intermittent’’
code. Most intermittent codes are caused by wiring
or connector problems. Defects that come and go
like this are the most difficult to diagnose; they
must be looked for under specific conditions that
cause them. The following checks may assist you in
identifying a possible intermittent problem:

•

Visually inspect related wire harness connectors.
Look for broken, bent, pushed out, or corroded
terminals.

•

Visually inspect the related harnesses. Look for
chafed, pierced, or partially broken wire.

•

Refer to any Hotline Newsletters or technical
service bulletins that may apply.

•

Use the DRBIII

t data recorder or co-pilot.

3.3.3

DISTANCE SINCE MI SET

The Euro Stage III OBD directive requires that

the distance traveled by the vehicle while the MI is
activated must be available at any instant through
the serial port on the standard data link connector.
This feature works as follows:

1. If the MI is illuminated due to a fault, the

distance count is updated (i.e. it is counting).

2. If there is a “stale” MI fault (i.e. the fault is still

frozen in memory but the MI has been extin-
guished due to 3 good trips), the distance count is
held (i.e. frozen).

3. If the distance count is being held due to (Item

2.) and the fault is cleared, the distance is
cleared (set to zero).

4. If the distance count is being held due to (Item

2.) and another MI occurs, the distance count is
reset (to 0) and begins updating anew.

5. If a fault occurs while the MI is already illumi-

nated due to a previous fault (the distance count
is updating), then the distance count continues
to update w/out interruption.

6. If the MI is flashing due to active misfire and

there is an “active” fault (i.e. matured fault for
which 3 good trips have not occurred), the dis-
tance count behaves as the MI in ON.

7. If the MI is flashing due to active misfire and

there is no “active” fault (i.e. the MI is flashing
for a 1 malf.), the distance count behaves as if
the MI is off (because it is not yet a matured
fault).

8. The distance count is cleared whenever the fault

is cleared. (Via 40 warm up cycles, or via scan
tool).

3.3.4

HANDLING NO TROUBLE CODE
PROBLEMS

Symptom checks cannot be used properly unless

the driveability problem characteristic actually
happens while the vehicle is being tested.

Select the symptom that most accurately de-

scribes the vehicle’s driveability problem and then
perform the test routine that pertains to this symp-
tom. Perform each routine test in sequence until the
problem is found. For definitions, see Section 6.0
Glossary Of Terms.

GENERAL INFORMATION

SYMPTOM

DIAGNOSTIC TEST

HARD START

CHECKING THE FUEL PRESSURE
CHECKING COOLANT SENSOR CALIBRATION
CHECKING THROTTLE POSITION SENSOR CALIBRATION
CHECKING MAP SENSOR CALIBRATION
CHECKING THE MINIMUM IDLE AIR FLOW
CHECKING IDLE AIR CONTROL MOTOR OPERATION
CHECKING EVAP EMISSION SYSTEM
CHECKING IAT SENSOR

START AND STALL

CHECKING PCM POWER AND GND CKT
CHECKING THE FUEL PRESSURE
CHECKING COOLANT SENSOR CALIBRATION
CHECKING THROTTLE POSITION SENSOR CALIBRATION
CHECKING MAP SENSOR CALIBRATION
CHECKING THE MINIMUM IDLE AIR FLOW
CHECKING IDLE AIR CONTROL MOTOR OPERATION

HESITATION/SAG/STUMBLE

SURGE

LACK OF POWER/SLUGGISH

SPARK KNOCK/DETONATION

GENERAL INFORMATION

SYMPTOM

DIAGNOSTIC TEST

CUTS OUT/MISSES

CHECKING PCM POWER AND GNT CKT
CHECKING THE FUEL PRESSURE
CHECKING THE MINIMUM IDLE AIR FLOW
CHECKING IDLE AIR CONTROL MOTOR OPERATION

BACKFIRE/POPBACK

CHECKING PCM POWER AND GND CKT
CHECKING THE FUEL PRESSURE
CHECKING MAP SENSOR CALIBRATION
CHECKING THE MINIMUM IDLE AIR FLOW

RUNS ROUGH/UNSTABLE/
ERRATIC IDLE

ENGINE STALLS IN GEAR

CHECK TCC OPERATION

POOR FUEL ECONOMY

CHECKING PCM POWER AND GND CKT
CHECKING THE FUEL PRESSURE
CHECKING COOLANT SENSOR CALIBRATION
CHECKING THROTTLE POSITION SENSOR CALIBRATION
CHECKING THE MINIMUM IDLE AIR FLOW
CHECKING IDLE AIR CONTROL MOTOR OPERATION
CHECKING EVAP EMISSION SYSTEM (WHEN EQUIPPED)
CHECKING IAT SENSOR

3.3.5

NO START INFORMATION

IMPORTANT NOTE:

If the Powertrain Control Module has been

changed and the correct VIN and mileage have not
been programmed, a DTC will be set in the ABS and
Air bag modules. In addition, if the vehicle is
equipped with a Sentry Key Immobilizer Module
(SKIM), Secret Key data must be updated to enable
starting.

FOR ABS AND AIR BAG SYSTEMS:

1. Enter correct VIN and Mileage in PCM.

2. Erase codes in ABS and Air Bag modules.

3.4

USING THE DRBIII

Refer to the DRBIII

t user’s guide for instructions

and assistance with reading trouble codes, erasing
trouble codes, and other DRBIII

t functions.

3.5

DRBIII

T ERROR MESSAGES AND

BLANK SCREEN

Under normal operation, the DRBIII

t will dis-

play one of only two error messages:

– User-Requested WARM Boot by pressing

MORE and NO at the same time.

ver: 2.29
date: 1 Oct 93
file: key_itf.cc
date: Jan 12 1994
line: 544
err: 0x1
User-Requested WARM Boot

Press MORE to switch between this display

and the application screen.

Press F4 when done noting information.

or User-Requested COLD Boot by pressing

MORE YES at the same time.

GENERAL INFORMATION

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