24-05-2025
P0603: Internal Control Module Keep Alive Memory (KAM) Error
What does the P0603 error code mean?
P0603 is a diagnostic trouble code that translates to "Internal Control Module Keep Alive Memory (KAM) Error." Specifically, it means the KAM — a part of the powertrain control module — has failed its self-test, which the powertrain control module runs periodically to make sure things are in good working order. Much like a computer's hard drive saves files even when the device is turned off, the KAM's job is to save or "keep alive" information that will be used the next time the vehicle is running.
Why is this issue important?
It's the KAM's job to save information about various systems, such as fuel delivery, timing and transmission control. This feedback is being constantly collected, allowing the powertrain control module to adaptively adjust to environmental factors, a person's driving style, and system wear as the vehicle is driven. If that data is no longer being stored or is inaccessible due to an issue with the KAM, the powertrain control module has to revert to default presets for these settings, which can vary widely from what has been learned, especially on older vehicles. Using those presets can result in rough idling, reduced fuel economy, or poor transmission performance, and it can cause unnecessary wear or damage if not fixed quickly. The code may be a symptom of an electrical issue, such as a failing battery, faulty wiring, or a malfunctioning powertrain control module.
Can I safely drive my car with this error code?
Until you know what's causing the P0603 error, it's best to drive the vehicle as little as possible. A KAM issue can cause erratic vehicle behavior, which may put you in an unsafe situation, and driving the vehicle using the original presets can lead to permanent issues if left unaddressed. The best course of action is to diagnose the issue with the vehicle as soon as possible before continuing to drive it regularly.
Common symptoms of the P0603 error code
The check engine light is illuminated.
The engine idles roughly or hesitates when you press the accelerator pedal.
Vehicle performance is sluggish, which may include slower-than-normal acceleration.
You may notice increased fuel consumption.
The engine is hard to start or won't start at all.
The transmission may shift unexpectedly or fail to upshift or downshift when appropriate.
The battery may drain, or there may be other electrical malfunctions.
How is the P0603 error code diagnosed?
Use an OBD-II scanner : Confirm the presence of the P0603 code and check for any related error codes before proceeding. It's possible that the P0603 error is being caused by another system problem.
: Confirm the presence of the P0603 code and check for any related error codes before proceeding. It's possible that the P0603 error is being caused by another system problem. Inspect the battery and charging system : Inspect the battery for loose connections or corroded terminals and attend to them as necessary. Using a multimeter, check the battery's voltage — it should be above 12 volts when the vehicle is off or around 14 volts with the engine running. You can also check the alternator's output or take the vehicle to an auto parts store that offers free alternator testing.
: Inspect the battery for loose connections or corroded terminals and attend to them as necessary. Using a multimeter, check the battery's voltage — it should be above 12 volts when the vehicle is off or around 14 volts with the engine running. You can also check the alternator's output or take the vehicle to an auto parts store that offers free alternator testing. Check the powertrain control module power supply : Inspect for loose connections, damaged wiring, or blown fuses on circuits that supply power to the powertrain control module.
: Inspect for loose connections, damaged wiring, or blown fuses on circuits that supply power to the powertrain control module. Inspect powertrain control module ground connections : Make sure the powertrain control module is properly grounded by testing with a multimeter. Poor grounding can lead to all sorts of electrical issues and erratic behavior.
: Make sure the powertrain control module is properly grounded by testing with a multimeter. Poor grounding can lead to all sorts of electrical issues and erratic behavior. Look for aftermarket modifications : If someone installed a performance tuning chip in the vehicle, it could be interfering with the powertrain control module's functioning.
: If someone installed a performance tuning chip in the vehicle, it could be interfering with the powertrain control module's functioning. Test the powertrain control module: If no external issues are found, the powertrain control module itself may be faulty and require further testing, a reset or replacement.
How is the P0603 error code repaired?
Tighten the battery terminal connections and clean any corrosion from them.
Replace a weak or failing battery to ensure consistent voltage to the powertrain control module.
Repair or replace a faulty alternator if it is not supplying enough voltage to keep the battery charged.
Repair or replace any damaged wiring, connectors, or fuses that supply power to the powertrain control module.
Clean and secure the powertrain control module ground connections to ensure proper electrical function.
Remove any aftermarket tuning devices or performance chips that may be interfering with the powertrain control module.
If necessary, reprogram or replace the powertrain control module if it is found to be malfunctioning.
After any repair attempt, use an OBD-II scanner to reset the error code and then conduct a test drive to verify the issue has been resolved. If the code does not return, the repair was successful.
Related reading
Follow the link below to reach our diagnostic check engine trouble codes catalog:
On-board diagnostics (BD-II) trouble code directory
