Test Description
WARNING: This page is about a different car, the 2003 Pontiac Grand Am and 2003 Oldsmobile Alero. However, it is still accessible from the selected car via links, so may be relevant.
- 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.
- 4. DTCs U1300, U1301 and 1305 may be retrieved with a history status. These DTCs are not the cause of the present condition.
- 5. When testing for shorts to B+, the tests must be run with ignition switch in the RUN position.
- 6. A state of health DTC (U1XXX) with a history status may be present along with a U1000 or U1255 having a current status. This indicates the malfunction occurred when the ignition was on.
- 7. Data link connector (DLC) terminals 2 and 5 provide the connection from the vehicles Class 2 serial data circuit and the Tech 2. A poor connection at this connector could cause corrupted data transmissions between the two devices. Pin 2 is the signal terminal and pin 5 is the signal ground terminal.
- 9. This step tests for an open from pin 2 of the DLC connector and the Fuse Block-Left I/P harness connector, it also tests for a short to B+ and Ground between the Fuse Block-Left I/P stationary junction terminals.
- 10. This is an active test of the Class 2 serial data circuit with the BCM being isolated from the communication bus, from the procedures in step 9. If you are able to communicate with the Class 2 serial data circuit, the BCM should be replaced.
- 11. This is an active test of the Class 2 serial data circuit with the IPC isolated from the communication bus. If you are able to communicate with the Class 2 serial data circuit during this step, the IPC should be replaced.
- 12. This is an active test of the Class 2 serial data circuit with the SDM isolated from the communication bus. If you are able to communicate with the Class 2 serial data circuit during this step, the SDM should be replaced.
- 13. This is an active test of the Class 2 serial data circuit with the Radio isolated from the communication bus. If you are able to communicate with the Class 2 serial data circuit during this step, the Radio should be replaced.
- 14. This is an active test of the Class 2 serial data circuit with the Digital Radio Receiver isolated from the communication bus. If you are able to communicate with the Class 2 serial data circuit during this step, the Digital Radio Receiver should be replaced. Not all vehicles are equipped with this device.
- 15. This is an active test of the Class 2 serial data circuit with the EBCM isolated from the communication bus. If you are able to communicate with the Class 2 serial data circuit during this step, the EBCM should be replaced.
- 16. This is an active test of the Class 2 serial data circuit with the PCM isolated from the communication bus. If you are able to communicate with the Class 2 serial data circuit during this step, the PCM should be replaced. The SDM is reconnected to allow at least one possible module for the Tech 2 to communicate with.
- 18. This is an active test of the Class 2 serial data circuit with the RCDLR, if the vehicle is equipped, isolated from the communication bus. If you are able to communicate with the Class 2 serial data circuit during this step, the RCDLR should be replaced.
- 20. This is an active test of the Class 2 serial data circuit with the VTD, if the vehicle is equipped, isolated from the communication bus. If you are able to communicate with the Class 2 serial data circuit during this step, the VTD should be replaced.
- 21. This step isolates all the modules from the Class 2 serial data circuit and tests for a short to B+ or Ground. The harness connector to the Fuse Block-Left I/P must be installed and Ignition switch placed in the RUN position in order to supply the B+ circuits routed throughout the vehicle.
- 22. In this step instructions are given to analyze each branch of the Class 2 serial data circuit, in order to isolate the cause of the short.
- 25. If there are no current DTCs that begin with a "U", the communication malfunction has been repaired.
- 27. The communication malfunction may have prevented diagnosis of the customer complaint.