THEORY OF OPERATION
This vehicle will come equipped with one of two types of ignitions, the IGNM (IGnition Node Module) or a KIN (Keyless Ignition Node). The KIN uses a Keyless Go Start/Stop push button for cycling the ignition on/off. The IGNM does not use a Keyless Go Start/Stop push button, instead providing a visible slot for the FOBIK to fit into for cycling the ignition on/off.
When the operator presses the Start/Stop Button on a KIN or cycles the FOBIK in a IGNM type ignition, the FOBIK is validated wirelessly by the RF Hub (Radio Frequency Hub Module). If the FOBIK is recognized as belonging to the vehicle and is inside the vehicle, the system allows the ignition state of the vehicle to be changed by the operator between the LOCK, ACCESSORY, RUN, and START ignition states.
LED Operation
The LEDs in the IGNM and Start/Stop Button provide visual indication of the ignition system and button use to aid the driver. The Logic for LED control is implemented in the IGNM and RF HUB. The IGNM and Start/Stop Button contain four LEDs
- OFF Indication
- ACC Indication (Accessory)
- ON Indication (On or Run)
- Ignition Switch Indicator (button backlight)
The LEDs indicate the vehicle ignition position and are driven by the CAN bus signals related to the ignition position. The Center LED (Ignition Switch Indicator) will blink if there is a related concern.
The RF HUB will log a DTC indicating an incorrect Ignition status value is present; in this state the ignition status is unknown. This will continue until the correct signal is received by the RF Hub.
EVIC Operation
The Keyless Go feature requires the vehicle to be equipped with an EVIC display for prompts and status information. The display messages are
- Service Keyless System
- FOB Not Detected
- FOB Left Vehicle
- Not in Park
- Push Brake Pedal and Push Button to Start
- Push Clutch Pedal and Push Button to Start
- Vehicle not in Park Warning
BCM/RF Hub Module Interaction
There are a few things that must take place before the starter relay can apply voltage to the starter. Below are some key points to check when diagnosing a no crank condition.
The BCM requires two signals from the RF HUB to verify the ignition is in the run or start position. The voltage on the F20 circuit is one of these signals. It can be monitored in both the RF HUB and BCM data display screens as the Ignition Run/Start under the "Sensor" value. The run or start position voltage on this circuit should be at or close to battery voltage.
Simultaneously the RF HUB busses the Ignition Run/Start status to the BCM. The BCM monitors the bussed input information as the secondary verification on the Ignition Run/Start status. The bussed messages can be monitored with the scan tool in both the RF HUB and BCM data display screens.
The F20 circuit voltage and the bussed ignition run/start status message received by the BCM must agree to enable starting. Once the vehicle is started, the loss of only one ignition signal will not cause the vehicle to cycle off as long as the other feed still indicates a "run status".
The RF HUB also requires an input from the Gated park switch (hardwired) and the OK to start CAN Bus message from the TCM (Crank Enable).
Diagnostic Aids
Note. The No Crank Diagnostic serves as an aid in diagnosing the concern and is intended to be used as a general guide, since each no crank condition can be unique.
The No Crank Diagnostic Test assumes all of the following to be true
- The condition is currently present.
- The TCM, PCM, RF HUB, and BCM are at the latest calibration (part number) levels.
- There are no active DTCs.
- There are no applicable Recalls.
- There are no applicable TSBs.
- There are no PCM inhibits (i.e. RPM, Trans Range, Clutch).
- The FOBIKs complete function and operation is correct.
- All battery cables and connections are clean and tight.
- There are no open fuses.
- The battery is fully charged and can pass a load test from the GR8 tester.
- The engine rotates freely.
- Any aftermarket equipment/wiring that has been installed is operating correctly.
Starter Relay Operation
In a no crank condition the Starter Relay can be missing power at pin 85, feed at pin 30, controlled ground at pin 86 or output at pin 87. Further explanation of how a relay operates is listed below
- Pin 85 receives power from the BCM once the parameters for the Ignition Switch position and status, and all inhibit monitors (i.e. clutch switch, RPM, etc.) are satisfied.
- Pin 30 is a constant B+ feed.
- Pin 86 is a controlled ground by a module (i.e. PCM or BCM). Once power is sent from the BCM to the pin 85 of the relay it passes through a coil and leaves the relay through pin 86 to the control module.
- Pin 87 is an output circuit to the Starter solenoid. Once the circuit on pin 86 is grounded by the control module, the coil winding in the relay magnetically pulls the internal switch closed. When the internal switch is closed the power at pin 30 is sent to pin 87 of the relay.
The customer may notice that the signal range of the Remote Keyless Entry (RKE) system is reduced. This condition may be due to the RKE antenna where the RKE key fob may need to be closer than 3 meters (10 feet) before the functions available on the key fob will operate. The diagnostic test is provided as a diagnostic aid for the dealer technician.
It is necessary to confirm the correct sales code(s) are present in the Standard and Optional Equipment sections of DealerCONNECT to determine if a factory or a Mopar® Accessory Remote Start kit was installed. If the vehicle has a Mopar® Accessory Remote Start kit, verify that at least 20 minutes has elapsed since the sales codes were added to DealerCONNECT. Once it has been confirmed that the proper sales codes have been added and the allotted time has passed, verify the vehicle has been configured properly using the scan tool. Also, make sure that the system shows as enabled in the BCM and that the temporary remote start override is set to disabled.
For any further assistance on diagnosing the installed Mopar® Accessory kit contact the Mopar® Accessories group at 800-84-MOPAR (66787).
See also:
• DTC INDEX