P0689: Engine Control Module Power Relay Sense Circuit Low
What to do
May not start or may cut out. The fault is on the supply side of the relay rather than its control, so ask for the relay contacts and the fuse it feeds to be checked.
What this code means
The power relay sense circuit reads low when the module expects voltage — the relay was commanded closed and no supply appeared. Distinct from the control-side faults: the command went out, the confirmation did not come back.
That points at the relay contacts, the fuse downstream of them, or the wiring carrying the supply, rather than at the coil circuit.
Likely causes
Start here
- Failed ECM power relay · easy
- Blown actuator supply fuse · easy
- Corroded relay socket · easy
- Broken wire in control circuit · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P0689.