P0603 on Ford
Internal Control Module Keep Alive Memory (KAM) Error
P0603 on Ford vehicles indicates internal control module keep alive memory (kam) error. Au7o has documented this code across 1 Ford model — most commonly on Explorer. This code means the engine computer's keep-alive memory (KAM), which stores learned adaptive values and settings between key cycles, has failed an internal check. The PCM relies on this memory to retain fuel trims, idle learning, and other adaptations. A KAM error can cause rough running, poor fuel economy, or transmission shift issues until the module relearns or is repaired.
Common Causes of P0603
- •Loss of constant battery power to the PCM (blown fuse, bad connection)
- •Weak or failing battery
- •Corroded or loose battery/ground connections
- •Recent battery disconnection without relearn
- •Internal PCM fault
- •Damaged PCM power/ground wiring
P0603 on Ford by Model
Ford Explorer(1 issue)
- Powertrain Control Module Reset Damaging Park System, Causing Rollaway or Engine Stall (Recall 25V239 / 25S35)2025
On certain 2025 Explorers built December 6, 2023 through September 6, 2024 with the 2.3L EcoBoost, the powertrain control module (PCM) can unexpectedly reset while the vehicle is operating. The reset can damage the transmission's park system or cause the engine to stall. A damaged park system can let the vehicle roll away when shifted to Park without the parking brake applied, and an engine stall produces a sudden loss of drive power. Approximately 24,655 vehicles are covered. Multiple owner reports of vehicles rolling away from Park and crashing prompted the action.
Looking for P0603 on a different make?
View P0603 across all makes →Frequently Asked Questions
What does P0603 mean on Ford?▼
P0603 stands for "Internal Control Module Keep Alive Memory (KAM) Error." This code means the engine computer's keep-alive memory (KAM), which stores learned adaptive values and settings between key cycles, has failed an internal check. The PCM relies on this memory to retain fuel trims, idle learning, and other adaptations. A KAM error can cause rough running, poor fuel economy, or transmission shift issues until the module relearns or is repaired. On Ford specifically, this code is documented across 1 model.
What causes P0603 on Ford vehicles?▼
Common causes on Ford: Loss of constant battery power to the PCM (blown fuse, bad connection), Weak or failing battery, Corroded or loose battery/ground connections, Recent battery disconnection without relearn, Internal PCM fault. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0603 on a Ford?▼
Repair costs vary widely depending on the root cause and specific Ford model.
Which Ford models have P0603 documented?▼
Au7o has documented P0603 on 1 Ford model: Explorer.