Code result
P0604
Internal Control Module Random Access Memory (RAM) Error
High severity
What it means
ECU self-test detected a RAM fault during runtime checks. This is an internal ECU defect; replacement or reflash with manufacturer support is generally required.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
ECU internal RAM fault
highOne of the most commonly reported causes for this code — check this first.
Module software outdated, reflash may resolve
lowLess common, but worth ruling out after the more likely causes.
Supply voltage outside specification
lowLess common, but worth ruling out after the more likely causes.
Related help
Get the full diagnosis
Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.
Diagnose P0604 freeNo credit card required