What is the P0689 fault number? What is the ECM/PCM Power Relay Sense Circuit Low error message? How can you fix the P0689 fault? What are the symptoms and causes for the P0689 fault code
What is the P0689? Fault code? What does it signify?
Code P0689 is a common code that refers to output circuit problems. This includes internal computer malfunctions. A code P0689 is triggered when the engine control module or powertrain controller module (PCM), detects a low voltage in the sensing section of the relay it powers.
The PCM power relay sends battery voltage safely to the ECM/PCM circuits. This is a contact type relay, activated via a cable from an ignition switch. This relay typically has five wires.
Relay’s working structure is simple. The powertrain relay is normally set in the on position. The relay receives continuous voltage from the battery. When the ignition switch turns to the off position, the relay is activated. “ON” position, the coil of the relay is energized. The electromagnet then causes the contacts to close. This completes circuit and sends electrical current from battery to PCM through a fused.
This code should only be applied to vehicles that use relays to supply power and ground signals for the ECM/PCM. A fused circuit is sometimes used instead of a power-relay.
P0689 fault codes can be found on many vehicles, including, but not limited, to Ford, Mercury and Dodge, Rams, Jeeps, Vauxhalls, Opels, Audi, Chrysler, Volkswagen and Chevrolet.
What causes the P0689 Fault code?
Here are some reasons why P0689 should be set.
- – ECM/PCM power relay defect
- – Corroded, burnt or shorted wires and/or connections, including battery terminals
- – A poor electrical connection between the power relay and ECM/PCM
- – Broken ECM/PCM fuse, or melted fuse link
- – Dead battery or weak battery
- – Low voltage during cranking
- – Defective ECM/PCM (rarely)
What are the symptoms of P0689 Malfunction code?
These symptoms may be present in vehicles with code P0689.
- – Illumination for the check engine light
- – There are no lights on the instrument panel
- – The engine might not start if there is no starting condition.
- – Engine may not start but it starts
- – The engine can be stopped immediately after it has started
- You may have to return the accessory.
- Engine problems can cause a variety of driving issues.
- – To limit engine power, the ECM/PCM may enter fail-safe mode
How do I fix the P0689 fault code?
Because this code is about electrical components, don’t rush to make a choice and try to replace the ECM/PCM immediately. This is a costly repair that is often the last resort to resolving the fault. This fault code is often caused by loose or corroded connection between the battery and relay. These cables should be checked immediately.
There are several repairs that can resolve the P0689 fault code.
- Repair of broken or loose battery cables
- – Charge the battery completely
- – Replace the battery if it’s dead
- – Replacing blownfuses
- – Repair and replacement of worn or damaged electrical wiring and its associated connectors
- – Replacing an ECM/PCM relay that is damaged or defective
- – Reprogramming and replacement of the faulty ECM/PCM (rarely).
How serious is the P0689 Fault code?
Even if your vehicle is starting with a set fault code P0689, it can still stop at any moment. This code can affect all security components. You may experience your headlights suddenly go out, your instrument panel lights may go dark, and the ABS and traction control may be disabled. This code must be resolved immediately to avoid any damage or accidents.
