Test Description
The numbers below refer to the step numbers 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. DTCs U1300, U1301, or U1305 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 having a current status. This indicates 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.
9. A poor connection at the DLC terminal would cause this condition but will not set a DTC.
10. An open in the class 2 serial data circuit between the DLC and the star connector will prevent the scan tool from communicating with any module. This condition will not set a DTC.
11. The class 2 serial data circuit is shorted to voltage or ground. The condition may be due to the wiring or due to a malfunction in one of the modules. When testing the wiring for a short, make sure there is not a module connected to the wire being tested. This test isolates the PCM class 2 serial data circuit.
13. This test isolates the SDM class 2 serial data circuit.
15. This test isolates the EBCM class 2 serial data circuit.
17. This test isolates the IPC class 2 serial data circuit.
19. This test isolates the theft deterrent control module class 2 serial data circuit.
21. This test isolates the DIC class 2 serial data circuit.
23. This test isolates the Radio class 2 serial data circuit.
33. If there are no current DTCs that begin with a "U"the communication malfunction has been repaired.
35. The communication malfunction may have prevented diagnosis of the customer complaint.