What it means
The main power relay drops out earlier than the calibrated post-run window allows. The ECU loses power before completing housekeeping (e.g. saving adaptions, parking the throttle), which causes adaptive learning to reset.
At a glance
- Usually lights the check-engine light
How it works
After the ignition is switched off, the ECM or PCM power relay should keep the controller powered for a calibrated period so it can finish shutdown tasks. P068A sets when the relay de-energizes too early, interrupting that post-run period and potentially disrupting saved adaptations or other shutdown functions.
Common causes
Most likely first.
- Power relay contacts worn or faulty
- Weak relay coil
- Loose or corroded relay connections
- Powertrain control module or relay-control circuit fault
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
How to diagnose it
- Record freeze-frame data and scan for related relay, controller-reset, or low-voltage codes before clearing them.
- Check whether the code returns immediately after key-off and whether the engine shows starting or relearn symptoms afterward.
- Inspect the power relay, socket, and control wiring for corrosion, loose connections, or heat damage.
- Monitor relay control and output through the key-off period using the manufacturer’s diagnostic procedure to confirm whether power drops early.
- Test the relay coil and contacts, then check the control circuit and controller command before considering a controller fault.
Common fixes
- Clean or repair loose or corroded relay connections.
- Repair damaged relay-control wiring.
- Replace a relay with worn contacts or a weak coil.
- Repair or replace the controller only after confirming the relay and its control circuit operate correctly.
Can I keep driving?
The engine may still run, but early power loss can interrupt controller shutdown tasks and cause lost adaptations or follow-up faults. Arrange repair soon, particularly if starting, idle, or drivability problems appear.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.