From Ross-Tech Wiki

17069/P0685 - ECM Power Relay Control Circuit (J271): Open Circuit

Possible Symptoms

  • Malfunction Indicator Light (MIL) ON
  • Engine doesn't start

Possible Causes

  • Voltage supply issue for ECM
  • Faulty ECM Relay (J271)

Possible Solutions

  • Test voltage supply to ECM
    • Check wiring and fuses
  • Replace Faulty ECM Relay (J271)

Special Notes

  • When found in a 2005 through 2007 2.5L NAR (North American Region) (1K) Jetta check the T121/62 (Red/Black) traced power wire to the ECM. If power is missing or a voltage drop is present that wire may be damaged anywhere between 6" and 18" from the connector itself. This will result in no communication in addition to a no-start.
  • When found in a Canadian Market (1J) chassis City Golf using engine code BEV, make sure that the B474 splice which powers T121a/62 (Red/Green) traced power wire to the ECM isn't corroded.