System Operation: Pats
">PATS status enable/disable target data PCM. The PCM sends the BCM a challenge request for a valid ID.
PCM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| PATS start request target data | BCM | The response from the BCM supplying the PCM challenge ID. If the BCM ID response is correct, the vehicle is allowed to start. |
PATS
Refer to: Interior Lighting - System Operation and Component Description .
The PATS function is controlled by the BCM. There are 2 main checks the PATS performs before allowing the vehicle to start. If either of these checks fail, the PATS does not allow the vehicle to start. These 2 checks are the BCM verifying that a programmed key was used to change the ignition lock cylinder to RUN or START and to verify the PCM identification to make sure it matches the PCM identification stored in memory.
When the BCM detects the ignition lock cylinder has been turned to RUN or START, it generates a challenge message. It sends the challenge message to the PATS transceiver on the transmit (TX) circuit. The transceiver in turn reads the key and generates a response message that is sent back to the BCM on the receive (RX) circuit. If the message received from the transceiver does not match a key stored in the BCM memory, the BCM prevents the vehicle from starting.
The second check is initiated by the BCM waking up the PCM by supplying voltage on the wake-up control circuit. The BCM activates the wake-up control circuit when any of the following occur:
- The driver door is opened.
- A key is inserted into the ignition lock cylinder.
- The ignition lock cylinder transitions to RUN or START.
Once the PCM is awake, the PCM sends the BCM a challenge message over the HS-CAN. When the BCM receives the challenge message, it generates a response and sends it back to the PCM. If the response from the BCM does not match the data in the PCM memory, this check fails and the vehicle does not start.
If the PCM identification and key verification pass, the PATS allows the vehicle to start. The PATS cannot disable or stall a vehicle that has already been started.