Reading Diagnostic Trouble Codes DTCs With a Scan Tool
The body control module (BCM) is able to store DTCs in memory as a current or a history DTC. The recommended method for reading DTCs stored in memory is by using a scan tool plugged into the data link connector (DLC). Follow the scan tool instructions supplied by the tool manufacturer. The DTCs will be stored in the memory of the instrument panel carrier (IPC).
Diagnostic Trouble Code (DTC) Diagnosis
This section uses diagnostic tables, wiring diagrams and descriptive text in order to direct you in performing specific tests in order to locate and repair the condition. The diagnostic table is a step by step procedure used in order to determine the circuit or component that is the source of the problem. The wiring diagrams and text describing the system, test conditions, failure conditions and actions taken when a DTC is set are located on the page facing the diagnostic table.
Current Codes
When the BCM determines that a failure condition for a particular DTC is set during the current ignition cycle, the BCM sets the code as a current DTC. All DTCs remain current until the condition for setting the fault is corrected or the next fault free ignition cycle has occurred. The current code then will become a history code only.
History Codes
When a DTC is set as a current fault code the DTC will automatically be stored as a history code as well
A history code can be cleared as follows:
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
| • | Using a scan tool. |
Important: BCM DTCs may appear in Passlock System DTC list. Record the BCM DTCs before clearing Passlock Codes.
The DTCs listed below are in order of importance. Diagnose the DTCs in the same order
Diagnostic Trouble Code | Description | Action |
|---|---|---|
U1255 | Loss of Class 2 Communication Malfunction | Data Link Communications System Check in Wiring Systems |
U1301 | Class 2 Data Link High | Data Link Communications System Check in Wiring Systems |
U1016 | Lost Communication With Engine Control System | Data Link Communications System Check in Wiring Systems |
B3031 | Security System Controller in Learn Mode | |
B3033 | Security System Indicates Tamper | |
B2958 | Security System Sensor Data Circuit High | |
B2957 | Security System Sensor Data Circuit Low | |
B2960 | Security System Sensor Data Incorrect But Valid | |
B2948 | Security System Sensor Power Circuit High | |
B2947 | Security System Sensor Power Circuit Low |
