Description: If a Code M6506 occurs, the Gateway Controller does not detect voltage on signal wire 8007 when commanded. The Gateway Controller provides power to the Engine Controller at Key On. When the Gateway Controller energizes the ECU Power wire, the Engine Controller will begin to start engine diagnostics, and control engine related functions. Possible Cause: •Signal wire 8007 shorted to ground. •Gateway Controller. •ECU Controller. •Moisture, corrosion, or pushed back pins in the Gateway Controller connectors, Engine Controller connectors, Engine to Mainframe harness connector, Engine harness, or the Mainframe harness. See Electrical Systems Connector Maintenance in Technical Information. •If the code is intermittent and not on at the time of testing, the cause of the code may not be found at this time. Probable causes may include: loose connections, corrosion, pushed back pins, the controller, the wire harness or a combination of these problems. Refer to Troubleshooting Intermittent Electrical Faults Procedures. 1 Check signal wire 8007 for a short to ground. Does signal wire 8007 have a short to ground? Repair or replace short to ground on signal wire 8007. No problem found. Perform wiggle test Wire 8007 is a tan wire that runs from engine ECU connector J7A PIN 19 and goes to gateway controller connector J1B PIN 4. Its a start, never seen that code myself.
