P068B

ECM/PCM Power Relay De-Energized Performance - Too Late

Q: Is it safe to drive with P068B?

Usually yes, but a main power relay that releases too late can leave modules powered and drain the battery, or cause the odd stall, so repair it soon.

Q: Can I just clear P068B?

You can, but it returns if the relay or its circuit still holds power too long after key-off.

ECM power supply Generic OBD-II High

What it means

P068B means the main ECM/PCM power relay is dropping out later than expected after key-off — the relay stays energized too long. The most common cause is a worn or sticking relay. Left unaddressed, a slow-releasing main relay can keep modules powered and drain the battery, and an intermittent relay can cause occasional stalls or hard starts.

High

Can I keep driving? Usually yes, but a main relay that drops out too late can drain the battery or cause occasional stalling or hard starts — have it checked soon.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Battery drain or the system staying powered after key-off
Occasional hard start or stall if the relay is intermittent
Other stored codes from momentary power interruptions

Common causes

Most likely first

Faulty ECM/PCM power relay with sticking or slow-releasing contactsLikely
Poor or corroded connection at the relay socketCommon
Damaged or shorted relay control wiringCommon
ECM/PCM relay-control driver faultLess often

How to diagnose & fix

Work through it in order

Scan and read freeze-frame to confirm the relay-timing fault.
Swap or bench-test the ECM/PCM power relay, or substitute a known-good relay.
Inspect the relay socket and control wiring for corrosion, backed-out pins, or shorts.
Check the ECM power and ground feeds; if wiring and relay are good, suspect the ECM driver. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P068B?+

Usually yes, but a main power relay that releases too late can leave modules powered and drain the battery, or cause the odd stall, so repair it soon.

Can I just clear P068B?+

You can, but it returns if the relay or its circuit still holds power too long after key-off.

Read & clear P068B yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX