Test A: Scan Tool Does Not Power Up
- Check for open or short to ground in Data Link Connector (DLC) battery positive voltage circuit between instrument panel fuse block and DLC terminal No. 16 (Orange wire). See Fig 1
. If open or short to ground does not exist in Orange wire, go to next step. If open or short to ground exists, repair as necessary. Perform appropriate diagnostic system check.
- Check for open in DLC ground circuit between ground and DLC terminal No. 4 (Black wire). If open does not exist in ground circuit, go to next step. If open exists in ground circuit, repair as necessary. Perform appropriate diagnostic system check.
- Check DLC terminals No. 4 and 16 for poor terminal contact or pushed out pins. If terminals are okay, go to next step. If terminal(s) are not okay, repair as necessary. Perform appropriate diagnostic system check.
- Scan tool may be faulty. See manufacturer's user guide. Obtain a known good scan tool. Perform appropriate diagnostic system check.
Courtesy of GENERAL MOTORS CORP.