Normal Operation
The Passive Anti-Theft System (PATS) uses a visual anti-theft indicator located in the Instrument Cluster (IC). This anti-theft indicator proves out for 3 seconds when the key is turned to the ON or START position under normal operation. Retrieve DTCs from the IC and the Transmission Control Module (TCM) to determine if there are any PATS -related DTCs that can indicate the cause of the no-start.
Once the PATS key read matches with one of the key codes programmed into the IC , the IC sends its ID over the High Speed Controller Area Network (HS-CAN) to the TCM . The TCM sends a message back, indicating it has received the IC message (ID) and also sends its ID back to the IC . When the IC receives this data transfer, it requests the TCM to start the vehicle by sending a message over the HS-CAN to the TCM . This "handshake" is necessary before the vehicle starts.
If there is a PATS concern, the indicator either flashes rapidly or glows steadily (for more than 3 seconds) when the key is turned to the ON or START position. PATS also flashes the anti-theft indicator every 2 seconds at key off to act as a visual theft deterrent. The anti-theft indicator operation is controlled by the IC .
If DTC U2510 is present, refer to DTC CHARTS in this service information.
- DTC U0100 (Lost Communication With ECM/PCM) - sets in continuous memory only when the IC loses communication with the PCM. The fault may not be present at the time of testing and only occurs during the PATS ID code reads. This DTC can be caused by an HS-CAN circuit concern or by the IC or the PCM.
- DTC U0101 (Lost Communication With TCM ) - sets in continuous memory only when the IC loses communication with the TCM . The fault may not be present at the time of testing and only occurs during the PATS ID code reads. This DTC can be caused by an HS-CAN circuit concern or by the IC or the TCM .
- DTC U2511 (CAN - Data Mis-Match [Receive Data Does Not Match Expected]) - sets in continuous memory only when the IC does not receive the expected response from the TCM over the HS-CAN and the fault may not be present at the time of testing. The data sent by the TCM does not match the data expected by the IC and this DTC is set. This DTC can be caused by the HS-CAN circuits between the IC and the TCM or by either module. This DTC can also be set if the battery voltage is low.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Low battery state of charge
- IC
- TCM