Replace, Don’t Repair, Coaxial Cables

Many GM vehicles are equipped with Low Voltage Differential Signaling (LVDS), Universal Serial Bus (USB) and Coaxial (Coax) cables for a number of screen and camera connections as well as high-speed data transmission.

For example, the Rear Seat Infotainment System on the 2021 Tahoe, Suburban, Yukon and Escalade features two video screen displays. (Fig. 1) Display 1, on the passenger’s side, is a smart device that is connected to the radio via an Ethernet cable. Display 1 also is connected to Display 2, on the driver’s side, and the Rear Consumer Port (USB and HDMI ports) via an LVDS cable.

 

Fig. 1

 

Another example is the Surround Vision Camera system, which uses a shielded Coaxial cable to connect each camera to the Video Processing Control Module. The Coaxial cable provides power for the camera and also carries the video image to the Video Processing Control Module.

The GM cable repair strategy is to replace these cables instead of repairing when addressing related vehicle issues. Never attempt to repair these types of cables on a vehicle. The entire cable/harness or component must be replaced.

TIP: LVDS, USB and Coax cables can be found in the Electronic Parts Catalog (EPC) by first identifying the main harness that contains the needed cable and then looking for the cable references in the accompanying graphic. (Fig. 2)

 

Fig. 2

 

Cables come complete with cable, terminals and connectors fully assembled, except for cables contained within a hybrid connector (cable plus non-cable circuits) If the cable connector bodies are damaged, the complete cable must be replaced. If the cable is contained within a hybrid connector, the replacement cable assembly will not include the hybrid connector body. In addition, for Coax cables only, the cables must be replaced as an assembly when multiple Coax segments are together as one assembly.

 

Cable Repairs

When replacing a faulty or damaged cable, first disconnect the cable connectors at both ends. Route the new cable along the harness and use tie-straps to attach the cable to existing harnesses or brackets. Be sure to not pinch the cable or bend it more than a 2-inch (5 cm) radius. Tape or foam can be used to prevent the cables from rattling if needed.

With the new cable installed, reconnect the connectors to the components. Cut the connectors off of the older cable as close to the harness breakout as possible without damaging the harness.

 

Ethernet Cables

Ethernet cables should be replaced and not repaired as well. Service harness kits are released per vehicle that contain a length for each leg/peripheral device. If an Ethernet wiring repair kit is not available, the entire harness must be replaced.

Ethernet cables come without the connector, but with the terminals crimped on the cable. The cables are a universal length to service as many applications as possible with the fewest part numbers. As a result, the cable received may be slightly (<500 mm) longer than the original cable contained within the factory harness. Any extra length of cable should be coiled up and secured.

After disconnecting the faulty or damaged cable connectors at both ends, remove the terminals from both connectors using the proper terminal removal tool. Overlay the properly twisted pair of wires provided in the Ethernet wiring repair kit and then route and secure the Ethernet wiring to the existing harness. Insert the terminals into the connectors and reconnect the components.

For more information about wiring repairs, refer to the appropriate Service Information. Be sure to always review the service procedures before beginning a repair in order to confirm the correct procedures are being followed.

 

– Thanks to Peter Joslyn