Concorde V6-2.7L VIN R (1998)
When the ignition is turned to the Run/Start position, the SKIM produces a Radio Frequency (RF) signal via an antenna which is located around the
ignition lock cylinder. The RF powers up the transponder chip inside the Sentry Key. The transponder chip then emits a coded signal that is received by
the SKIM antenna. If this coded signal is valid, the SKIM sends an "VALID KEY" message to the PCM. If the first transponder signal is not valid, the
SKIM will attempt four more times to receive a correct transponder signal. If a valid signal is not received, the SKIM stores a diagnostic trouble code
and sends a "INVALID KEY" message to the PCM. Then the PCM will only allow the engine to start for two seconds then stall. This start and stall will
be allowed up to six times, after which the PCM will disable the starter relay.
The SKIS includes two valid Sentry Keys from the factory. If the customer wishes, additional uncoded Sentry Key blanks are available. These blank keys
must be cut to match a valid key, but the engine will not start unless the transponder chip inside the blank key is programmed to that particular vehicle.
The Sentry Key Immobilizer System (SKIS) can be programmed to recognize a total of eight keys.
The SKIM sends messages to the Body Control Module (BCM) over the PCI bus to control the Vehicle Theft Security System (VTSS) indicator lamp.
The SKIM sends a message to the BCM to turn the lamp on for about three seconds when the ignition is turned to the Run/Start position as a bulb test. If
the indicator lamp comes on and stays on after the bulb test, it indicates that the SKIM has detected a system malfunction and/or that the SKIS has
become inoperative. If an invalid key is detected in the ignition key cylinder with the ignition switch in the Run/Start position, or when the SKIM has
entered its customer key programming mode, the SKIM will flash the VTSS indicator lamp on and off.
Speed Proportional Steering
The Speed Proportional Steering, used on LHS vehicles only, features automatically adjusted steering effort based on the vehicle speed. The amount of
effort required to turn the steering wheel is determined by a 500-Hz Pulse Width Modulated (PWM) output signal. The desired duty cycle of the PWM
is selected from a calibration table internal to the Body Control Module (BCM).
To obtain the desired solenoid current the duty cycle of the solenoid can be compensated according to a current measuring feedback circuit. The speed
proportional steering system is always active with the ignition on.
The 500Hz PWM output signal is capable of generating a duty cycle from 0% (full off - minimum steering assist) to approximately 50% duty cycle (full
on - maximum steering assist) in small increments. The duty cycle is determined by vehicle speed and is continuously modified by solenoid current
feedback information. With the engine running and vehicle speed between 0 km/h (0 mph) and approximately 32 km/h (20 mph) the duty cycle will be
about 50%. Between approximately 32 km/h (20 mph) and 100 km/h (60 mph) the duty cycle will gradually decrease to 0% based upon vehicle speed.
Above approximately 100 km/h (60 mph) there is no assist provided by the speed proportional steering system. Maximum solenoid current will be
limited to one amp but the system operates at about 0.5 amp.
The Speed Proportional Steering System can detect three failure moves relating to the Speed Proportional Steering PWM driver located in the BCM. If
any Diagnostic Trouble Code (DTC) is set, the solenoid is shut off, unless the condition goes away before approximately 10 seconds. Once the DTC is
set, the solenoid will remain oft for the remainder of the ignition cycle.
1. An open or shorted to ground circuit fault is detected by monitoring the feedback circuit. If the BCM detects that the feedback circuit has zero
current when the software indicates the solenoid circuit should have current, the DTC will be set. This test is performed every 250 milliseconds.
2. A short to voltage fault is detected by monitoring the feedback circuit. The DTC will be set when the BCM has sensed that there was current on
the solenoid feedback circuit when the solenoid was turned off.
3. An over temperature or thermal shutdown DTC will be set by default if the internal diagnostic pin of the solenoid driver is at a low level, but the
feedback measurement does not show a high PWM output current.
Trouble Codes
Typically, modules have Diagnostic Trouble Codes that are referred to as either active or stored. In the case of the Sentry Key Immobilizer Module,
however, all codes are stored codes. The two various types of stored codes in the SKIM can be considered to be either current or pre-existing codes. If
more than one code exists, diagnostic priority should be given to the current code(s). See test 1A to determine what codes are current and what ones are
pre-existing. A current code indicates a malfunction that is CURRENT at the time of vehicle service. A pre-existing code indicates the malfunction is not
currently present. If a malfunction is not detected after 80 ignition cycles, the code will automatically be erased.
Vehicle Communication
The Chrysler Programmable Communication Interface multiplex system (PCI bus) consists of a single wire. The Body Control Module (BCM) acts as a
splice to connect each module and the Data Link Connector (DLC) together. Each module is wired in parallel to the data bus through its PCI chip set and
uses its local ground as the bus reference. The wiring is a minimum 20 gage. The PCI bus wire insulation color will be yellow with a violet tracer. An
extra tracer color may be added along with the violet to help distinguish between different node connections.
The bus is designed to handle a maximum number of nodes to meet all of the bus load and timing requirements. The bus resistance and capacitance is
designed to provide a maximum level of filtering without distorting the bus symbols. This is why extra capacitance and resistance should not be added to
the PCI Data Bus circuitry.
