P0603 Internal Control Module Keep Alive Memory (KAM) Error

P0603 indicates an internal control module keep-alive memory error. The module lost or failed to validate stored adaptive memory data.

Code details

Generic OBD-II · P0

System: Computer
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace a controller from P0603 alone; keep-alive power and battery history must be checked first.

Symptoms of P0603

Check-engine light, sometimes with several unrelated codes at once.
Warning lights, a no-start, or intermittent electrical faults.
Communication or module-reset problems on a scan tool.

Common causes of P0603

Low battery voltage, poor grounds, corroded connectors, or blown fuses.
Wiring or network (CAN bus) faults between modules.
A module software/programming issue, or rarely a failed controller.

Useful checks before replacing parts

Check battery condition, keep-alive power feed, fuses, grounds, voltage drops, and connector condition at the module.
Review whether the battery was disconnected, discharged, jump-started, or replaced before the code appeared.
Confirm the code returns after stable power is restored because low voltage can trigger memory-related faults.

Related OBD-II codes

These nearby computer entries can help compare wording and pin down the fault area.