LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2021 >> Edge ST-Line, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 502 (Engine Controls - Powertrain DTC Charts & Descriptions (Diesel)) >> Diagnostic Trouble Code (DTC) Charts and Descriptions >> P0685 - ECM/PCM Power Relay Control Circuit/Open
April 5, 2026: LEMON Manuals is launched! Read the announcement.

P0685 - ECM/PCM Power Relay Control Circuit/Open

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2022 Ford F-550 Super Duty, 2022 Ford F-450 Super Duty, 2022 Ford F-350 Super Duty, 2022 Ford F-250 Super Duty, and 2021 Ford F-550 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
DTC DESCRIPTION P0685 - ECM/PCM POWER RELAY CONTROL CIRCUIT/OPEN

Description:  This DTC sets when the ISP-R circuit indicates the ignition is in the OFF, ACC, or LOCK position, and the amount of time the PCM remains powered through the PCM power relay exceeds a predetermined amount of time.
Possible Causes: 
  • PCMRC circuit open
  • PCMRC circuit short to voltage
  • Damaged PCM power relay
Diagnostic Aids: 
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
All GO to PINPOINT TEST AJ .