Scan Tool Does Not Communicate With Class 2 Device

SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE













































Circuit Description
Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. Connecting a scan tool to the DLC allows communication with the modules for diagnostic purposes.

Diagnostic Aids
The engine will not start when there is a total malfunction of the class 2 serial data circuit while the engine is not running.

Test Description
The number(s) below refer to the step number(s) on the diagnostic table .
2. A partial malfunction in the class 2 serial data circuit uses a different procedure from a total malfunction of the class 2 serial data circuit.
3. The DTC U1300 and U1301 may be retrieved with a history status. These DTCs are not the cause of the present condition.
6. A State of Health DTC with a history status may be present along with a U1000 with a current status. This indicates that the malfunction occurred when the ignition was on.
7. Data link connector terminals 2 and 5 provide the connection to the class 2 serial data circuit and the signal ground circuit respectively.
10. An open in the class 2 serial data circuit between the DLC and the body control module (BCM) will prevent the scan tool from communicating with any module. This condition will not set a DTC.
11. If communication can be established, the malfunction is not in the BCM or the wiring from the DLC to the BCM.
12. This test attempts to establish communication with the IRC.
13. This test attempts to establish communication with the PCM.
14. This test attempts to establish communication with the IPC.
15. This test attempts to establish communication with the SDM.
16. This test attempts to establish communication with the EBCM.
17. This test analyzes the condition of the wiring and connectors in the class 2 serial data circuit of the BCM.
18. This test analyzes the condition of the wiring and connectors in the class 2 serial data circuit of the IRC.
19. This test analyzes the condition of the wiring and connectors in the class 2 serial data circuit of the PCM.
20. This test analyzes the condition of the wiring and connectors in the class 2 serial data circuit of the IPC.
21. This test analyzes the condition of the wiring and connectors in the class 2 serial data circuit of the SDM.
22. This test analyzes the condition of the wiring and connectors in the class 2 serial data circuit of the EBCM.
29. If there are no current DTCs that begin with a U, the communication malfunction has been repaired.
32. The interruption of the class 2 serial data circuit may have prevented the diagnosis of the customer complaint.