P0688 Ford Electronic Control Module Power Relay Control Circuit Open
Possible causes
– Weak battery- Low voltage while cranking
– Faulty Engine Control Module (ECM) relay
– Blown ECM fuse
– Faulty ECM
– ECM harness is open or shorted
– ECM circuit poor electrical connection
– Faulty Engine Control Module (ECM) relay
– Blown ECM fuse
– Faulty ECM
– ECM harness is open or shorted
– ECM circuit poor electrical connection
Tech description
Check all the ECM fuses, if the fuses are OK try replacing the ECM relay.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
Ford Vehicle:Ford Escape,Ford Focus Flexifuel,Ford Mustang,Ford Fusion,Ford Taurus,Ford F-Series,Ford Explorer,Ford C-Max,Ford Escape,Ford Edge,Ford Explorer,Ford Flex,Ford Expedition,Ford Transit Connect,Ford F1-50,Ford E-Series Wagon,Ford Super Duty,Ford Fusion Hybrid SE,Ford C-MAX Hybrid SEL,Ford C-MAX Energi,Ford Fusion Energi SE,Ford Fucos Electric,Ford E-Series Van,Ford E-Series Cutaway,Ford Super Duty Pick Up,Ford Chassis Cab,Ford F-650/F-750,Ford Stripped Chassis