P064D
Internal Control Module O2 Sensor Processor Performance Bank 1
ECM / O2 processor
Generic OBD-II
High
What it means
P064D sets when the ECM's internal oxygen-sensor signal processor for bank 1 fails its self-check, so the computer can't reliably process O2 feedback used to trim fuel. The engine still starts and runs, but fuel control and emissions can suffer. It usually points to ECM power/ground problems or an internal module fault.
High
Can I keep driving? Usually drivable — the engine still starts and runs, but fuel trim and emissions may suffer as the ECM loses reliable O2 feedback, so get it checked.
Common symptoms
What you'll notice
- Check-engine light on
- Poor fuel economy
- Possible failed emissions test
- Fuel control may default to a fixed strategy, causing slightly rough running
Common causes
Most likely first
- Internal ECM oxygen-sensor processor faultLikely
- Open or shorted ECM power supply circuitCommon
- Weak battery or poor ECM power/ground connectionsCommon
- ECM programming issue or a faulty ECMLess often
How to diagnose & fix
Work through it in order
- Check and clean the battery terminals and confirm ECM power and ground are solid, then clear the code.
- Inspect the ECM power supply wiring for opens, shorts, or high resistance.
- Check for an ECM software update that addresses the internal processor fault.
- If it returns after voltage and wiring are verified, reprogram or replace the ECM. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P064D?+
Generally yes — despite some sources, this code does not stop the engine from starting. It affects O2-based fuel control, so expect worse economy and possible emissions issues until fixed.
Can I just clear P064D?+
It may clear after a battery/power fix, but a genuine internal processor fault will return once the ECM re-runs its self-check, requiring reprogramming or replacement.
Related codes
Often seen with P064D
Read & clear P064D yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX