Certain criteria must be met for a diagnostic
trouble code to be entered into the SKIM memeory.
The criteria may be a range of; Input voltage, CCD
Bus message, or coded messages to the SKIM. If all
of the criteria for monitoring a circuit or function
are met and a fault is sensed, a diagnostic trouble
code will be stored in the SKIM memory.
3.2.8 SKIS OPERATION
When ignition power is supplied to the SKIM, the
SKIM performs an internal self-test. After the self-
test is completed, the SKIM neergizes the antenna
(this activates the transponder chop responds to the
challenge by generating an encrypted response
message using the following:
Secret Key -This is an electronically stored
value (identification number) that is unique to each
SKIS. The secret key is stored in the SKIM, PCM
and all ignition key tranponders.
Challenge -This is a random numbr that is
generated by the SKIM at each ignition key cycle.
The secret key and challenge are plugged into an
algorithm that produces the encrypted response
message. The transponder uses the crypto algo-
rithm to receive, decode and respond to the message
sent by the SKIM. After responding to the coded
message, the transponder sends a transponder ID
message to the SKIM. The SKIM compares the
transponder ID to the available valid key codes in
the SKIM memory (8 key maximum). After validat-
ing the key the SKIM sends a CCD Bus message
called a ``Seed Request'' to the engine controller
then waits for a PCM response. If the PCM does not
respond, the SKIM will send the seed request agian.
After three failed attempts the SKIM will stop
sending the seed request and store a trouble code. If
the PCM sends a seed response, the SKIM sends a
valid/invalid key message to the PCM. This is an
encrypted message that is generated using the
following:
VIN -Vehicle Identification Number
Seed -This is a random number that is generated
by the PCM at each ignition key cycle.
The VIN and seed are plugged into a rolling code
algorithm that encrypts the ``valid/invalid key'' mes-
sage. The PCM uses the rolling code algorithm to
receive, decode and respond to the valid/invalid key
message sent by the SKIM. After sending the valid/
invalid key massage the SKIM waits 3.5 seconds for
a PCM status message from the PCM. If the PCM
does not respond with a valid key message to the
SKIM, a fault is detected and a trouble code is
stored.
The SKIS incorporates a warning lamp (``ALARM
SET'') located in the message center. The lamp
receives switched ignition voltage and is hardwired
to the body control module. The lamp is actuated
when the SKIM sends a CCD Bus message to thebody controller requesting the lamp on. The body
controller then provides the ground for the lamp.
The SKIM will request lamp operation for the
following:
- bulb checks at ignition on
- to alert the vehicle operator to a SKIS malfunc-
tion
For all faults except transponder faults and VIN
mismatch, the lamp remains on steady. In the event
of a tranponder fault the light flashes at a rate of 1
Hz (once per second). If a fault is pesent the lamp
will emain on or flashing for the complete ignition
cycle. If a fault is stored in SKIM memory which
prevents the system form 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 disables the starter relay until the fault is
corrected.
3.2.9 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 integ-
rity 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.
12-volt pull-ups, drivers 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, engine controller and transpon-
der ship (ignition key). When replacing the PCM it
is necessary to program the secret key into the
PCM.
1. Turn the ignition on (transmission in park/
neutral).
2. Use the DRB and select ``THEFT ALARM'',
SKIM then MISCELLANEOUS''.
3. Select ``PCM REPLACED''.
4. Enter secured access mode by entering the vehi-
cle four-digit PIN.
6
GENERAL INFORMATION
ProCarManuals.com
TEST ACTION APPLICABILITY
3 Ignition On, Engine Not Running.
With the DRB, read TPS Sensor voltage. Throttle must be against stop.
Is the voltage 0.92 or less with the Throttle closed?All
Ye s®Go To 4
No®Replace the Throttle Position Sensor.
Perform Powertrain Verification Test VER-5A.
4 Turn ignition On.
With the DRB in sensors, read the ªEngine Coolant Tmp Degº value.
Note: If engine coolant temperature is above 82ÉC (180ÉF), allow the engine
to cool until 62ÉC (150ÉF) is reached.
Start the Engine.
While monitoring the DRB, allow the engine to reach normal operating temperature
above 82ÉC (180ÉF).
Did the engine coolant temperature value reach 82ÉC (180ÉF) or above?All
Ye s®Go To 5
No®Replace the Engine Coolant Temperature Sensor.
Perform Powertrain Verification Test VER-5A.
5 Turn ignition On.
With the DRB in sensors, read the88Eng Coolant Tmp Deg'' value
Note: If engine coolant temperature is above 82ÉC (180ÉF), allow the engine
to cool until 62ÉC (150ÉF) is reached.
Start the Engine.
While monitoring the DRB, allow the engine to reach normal operating temperature
above 82ÉC (180ÉF).
Was the coolant temperature value increase a smooth transition?All
Ye s®Go To 6
No®Replace the Engine Coolant Temperature Sensor.
Perform Verificatino Test VER-5A.
6 Turn ignition off.
Connect a Vacuum Gauge to a Manifold Vacuum source.
Start the engine.
Allow the engine to idle.
Note: If engine will not idle, maintain a constant RPM above idle.
Using the DRB in Sensors, read the MAP Sensor vacuum value.
Is the DRB reading within 19of the Vacuum Gauge reading?All
Ye s®Go To 7
No®Replace the MAP Sensor.
Perform Powertrain Verification Test VER-5A.
76
DRIVEABILITY
P-0171±1/1 FUEL SYSTEM LEAN ÐContinued
ProCarManuals.com
TEST ACTION APPLICABILITY
3 Ignition On, Engine Not Running.
With the DRB, read TP Sensor voltage. Throttle must be against stop.
Is the voltage 0.92 or less with the Throttle closed?All
Ye s®Go To 4
No®Replace the Throttle Position Sensor.
Perform Powertrain Verification Test VER-5A.
4 Turn ignition on.
With the DRB in sensors, read the ªEng Coolant Tmp Degº value.
Note: If engine coolant temperature is above 82ÉC (180ÉF), allow the engine
to cool until 62ÉC (150ÉF) is reached.
Start the Engine.
While monitoring the DRB, allow the engine to reach normal operating temperature
above 82ÉC (180ÉF).
Did the engine coolant temperature value reach 180ÉF or above?All
Ye s®Go To 5
No®Replace the Engine Coolant Temperature Sensor.
Perform Powertrain Verification Test VER-5A.
5 Turn ignition On.
With the DRB in sensors, read the ªEng Coolant Tmp Deg'' value
Note: If engine coolant temperature is above 82ÉC (180ÉF), allow the engine
to cool until 62ÉC (150ÉF) is reached.
Start the Engine.
While monitoring the DRB, allow the engine to reach normal operating temperature
above 82ÉC (180ÉF).
Was the coolant temperature value increase a smooth transition?All
Ye s®Go To 6
No®Replace the Engine Coolant Temperature Sensor.
Perform Verification Test VER-5A.
6 Turn ignition off.
Connect a Vacuum Gauge to a Manifold Vacuum source.
Start the engine.
Allow the engine to idle.
Note: If engine will not idle, maintain a constant RPM above idle.
Using the DRB in Sensors, read the MAP Sensor vacuum value.
Is the DRB reading within 19of the Vacuum Gauge reading?All
Ye s®Go To 7
No®Replace the MAP Sensor.
Perform Powertrain Verification Test VER-5A.
7Note: Engine must be at operating temp and in closed loop to perform this
test.
Start engine and run until operating temp and closed loop mode is reached.
With the DRB under System Tests, go to ªPurge Vapors Test''. Observe the Short
Term Adaptive value and press 3 to flow.
Note: Short Term Adaptive should change.
Did the Short Term Adaptive value change?All
Ye s®Go To 8
No®Refer to symptom *CHECKING EVAPORATIVE EMISSION
SYSTEM in the DRIVEABILITY category.
80
P0172 -1/1 FUEL SYSTEM RICH ÐContinued
ProCarManuals.com
TEST ACTION APPLICABILITY
3 Turn ignition off for 10 seconds, then start engine and let idle.
Allow engine to reach normal operating temperature.
With the DRB in Systems Test, perform the IAC Wiggle Test.
Note: The idle speed should raise and lower with the display.
Does the IAC Motor operate properly?All
Ye s®Go To 4
No®Go To 6
4 Turn ignition off for 10 seconds, then start engine and let idle. Allow engine to reach
normal operating temperature.
With the DRB in Systems Test, perform the IAC Wiggle Test.
Note: The idle speed should raise and lower with the display.
Wiggle the Wiring Harness from the IAC Motor to the PCM.
Observe for the IAC Motor to stop operating.
Did the IAC Motor stop operating at any time?All
Ye s®Repair the Harness or Connectors as necessary.
Perform Powertrain Verification Test VER-5A.
No®Go To 5
5 Ignition Off
Using the schematic as a guide, inspect the Wiring and Connectors.
Were any problems found?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
No®Test Complete.
6 Start engine and let idle.
Disconnect the IAC Motor Connector.
Note: Check connectors - Clean/repair as necessary.
Using a Voltmeter, measure the IAC Driver #1 Circuit.
Was the voltage over 5.0 volts at any time?All
Ye s®Go To 7
No®Refer to symptom P-0505B IDLE AIR CONTROL MOTOR CIR-
CUIT in the DRIVEABILITY category.
7 Ignition Off
Disconnect the IAC Motor Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure between IAC #4 Driver and ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the IAC #4 Driver Circuit shorted to ground.
Perform Powertrain Verification Test VER-5A.
No®Go To 8
160
DRIVEABILITY
P-0505 IDLE AIR CONTROL MOTOR CIRCUITS ÐContinued
ProCarManuals.com
TEST ACTION APPLICABILITY
3 Ignition off.
Remove the Throttle Body per service information procedure.
Note: Clean Throttle Body in a well ventilated area and wear rubber gloves.
While holding the Throttle open spray entire Throttle Body Bore with Mopar parts
cleaner.
Using a soft scuff pad, clean the Throttle Body Bore and Throttle Plate.
Using compressed air, dry the Throttle Body and install Throttle Body on Manifold.
Reconnect IAC Motor Connector and reset the IAC Motor Steps with the DRB.
Start engine and let idle.
With the DRB, actuate the minimum air flow.
Is the idle RPM within the range shown in the chart? Refer to the Service
Information.All
Ye s®Test Complete.
No®Replace the Throttle Body.
Perform Powertrain Verification Test VER-5A.
4 Ignition Off
Start engine, allow engine idle to stabilize for 60 seconds.
With the DRB, read target idle and engine RPM.
Is the engine RPM within +200/-100 RPM of target idle?All
Ye s®Go To 5
No®Go To 8
5 Ignition Off
Remove the IAC Motor from the housing.
Turn Ignition on with Engine Not Running.
With the DRB, actuate the IAC Stepper Motor.
Wiggle the Wiring Harness from the IAC Motor to the PCM.
Did the IAC stop operating at any time?All
Ye s®Repair the Harness or Connectors as necessary.
Perform Powertrain Verification Test VER-5A.
No®Go To 6
6 Ignition Off
Using the schematic as a guide, inspect the Wiring and Connectors.
Were any problems found?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
No®Go To 7
7 Ignition On, Engine Not Running
Check Throttle Plate and Linkage for a binding condition.
The Throttle Linkage must be free and the Throttle Plate at the idle
position.
Ensure Throttle Plate is fully closed and against its stop.
Is the Throttle Plate and Linkage okay?All
Ye s®Test Complete.
No®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
181
DRIVEABILITY
P-1294 TARGET IDLE NOT REACHED ÐContinued
ProCarManuals.com
TEST ACTION APPLICABILITY
8 Ignition Off
Start engine, allow engine idle to stabilize for 60 seconds.
With the engine running at idle, the DRB in Systems Test, perform the IAC wiggle
test.
The idle speed should raise and lower with the display.
Does the RPM raise and lower correctly?All
Ye s®Go To 9
No®Refer to symptom P-0505 IDLE AIR CONTROL MOTOR CIR-
CUITS in the DRIVEABILITY category.
9 Ignition Off
Start engine, allow engine idle to stabilize for 60 seconds.
Check engine Vacuum Hoses and Components for vacuum leaks.
Ensure PCV Valve is the correct part and is operating correctly.
Were any problems found?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
No®Go To 10
10 Ignition Off
Remove the IAC Motor from the housing.
Turn Ignition on with Engine Not Running.
With the DRB, actuate the IAC Stepper Motor.
Wiggle the Wiring Harness from the IAC Motor to the PCM.
Did the IAC stop operating at any time?All
Ye s®Repair the Harness or Connectors as necessary.
Perform Powertrain Verification Test VER-5A.
No®Go To 11
11 Ignition On, Engine Not Running
Check Throttle Plate and Linkage for a binding condition.
The Throttle Linkage must be free and the Throttle Plate at the idle
position.
Ensure Throttle Plate is fully closed and against its stop.
Is the Throttle Plate and Linkage okay?All
Ye s®Go To 12
No®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
12 Ignition Off
Using the schematic as a guide, inspect the Wiring and Connectors.
Were any problems found?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
No®Test Complete.
182
DRIVEABILITY
P-1294 TARGET IDLE NOT REACHED ÐContinued
ProCarManuals.com
Symptom:
* CHECKING IDLE AIR CONTROL MOTOR
POSSIBLE CAUSES
ENGINE SPEED WITHIN TOLERANCE
IAC MOTOR CONNECTOR OBSERVABLE DEFECT
ENGINE HAS VACUUM LEAKS
IAC MOTOR DEFECTIVE
TEST ACTION APPLICABILITY
1 Engine Running
With the DRB in actuator tests, set the engine speed to 1400 RPM and then to 900
RPM.
Did the engine RPM go from 1400 RPM to 900 RPM?All
Ye s®With the DRB, stop all tests, test complete.
No®Go To 2
2 Engine Running
Inspect the engine for any vacuum leak(s).
Is there any vacuum leaks?All
Ye s®Repair Vacuum Leak(s) as necessary.
Perform Powertrain Verification Test VER-2A.
No®Go To 3
3 Turn the ignition off.
Disconnect the IAC motor harness connector.
Start the engine and allow it to idle.
Using a test light connected to ground, probe the IAC Driver #1 circuit.
Repeat the above test for the remaining IAC Driver circuits.
Did the test light turn on and off at any time for each IAC driver circuit?All
Ye s®Go To 4
No®Go To 5
4 Turn the ignition off.
Disconnect the IAC motor harness connector.
Start the engine and allow it to idle.
Using a test light connected to battery positive, probe the IAC Driver #1 circuit.
Repeat the above test for the remaining IAC Driver circuits.
Did the test light turn on and off at any time for each IAC driver circuit?All
Ye s®Go To 6
No®Go To 8
242
DRIVEABILITY
ProCarManuals.com