P0603

Internal Control Module Keep Alive Memory (KAM) Error

Car Fault Codes Engine computer & electrical

Can you still drive? Yes, normally

Who can fix it? Needs a workshop

Typical repair time 15 minutes – 4 hours

Typical cost SAR 50 to 5,000

What it means

Keep alive memory (KAM) is the part of the engine computer (ECU) that stores learned values such as fuel trims and idle settings after the vehicle is switched off, using constant battery power. The computer found that this memory lost its contents, and the most common reason is an interrupted constant power feed, not a failed computer.

Symptoms4

Check engine light on.
Briefly unstable idle after starting until the computer relearns.
Temporarily different shifting on some vehicles.
Often no clear symptom other than the light.

Possible causes5

Battery disconnected, replaced or fully drained.
Loose or corroded battery terminals.
Blown fuse on the constant power feed to the computer.
Broken or corroded constant power wire or ground.
Internal engine computer failure (rare).

How to diagnose5

Ask whether the battery was recently disconnected or replaced, since the code often sets once after that.
Inspect the battery and its terminals and make sure they are clean and tight.
Clear the code, then switch off and restart several times to see if it returns.
Check the constant power fuse and confirm battery voltage reaches the computer with the key off.
Inspect the grounds and connectors at the computer.

How to fix6

Clear the code if it set after a battery disconnect and does not return.
Clean and tighten the battery terminals, and replace a weak battery.
Replace a blown fuse and find the reason it blew.
Repair the constant power wire or ground.
Replace and program the engine computer only if an internal fault is proven.
Clear the codes and confirm the code does not return over several drive cycles.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

Most cases are solved by clearing the code or fixing a battery terminal or fuse at low cost; the upper end applies only if the computer itself has failed.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

The code appeared after a battery change. Is something wrong?

Usually not. Disconnecting the battery erases the keep alive memory, so the computer logs the code once and it can be cleared. If it returns, check the constant power feed.

Is this code serious?

It is not harmful to the engine, but if it keeps returning the computer keeps losing learned values, which can cause an unstable idle and higher fuel use.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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