How is fault code P0603 fixed?

A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training. 1. Load test the battery and check it properly. You want over 12.4V rested with the engine off and a steady 13.8 to 14.4V running. A battery that reads fine at rest but collapses under load is a classic cause of this code 2. Pull the terminals off, clean the posts and clamps back to bright metal, then refit them tight. Five minutes of work that clears a fair share of these 3. Read the freeze frame data alongside the code so you can see what the engine was doing when it logged, and note any companion codes 4. Check the fuses feeding the ECU's permanent live, particularly the always-on memory feed, and look for anything aftermarket spliced into nearby circuits 5. Inspect the loom and connectors running to the module for damage and corrosion, and confirm the earth strap is clean and torqued down. A multimeter voltage-drop test on the earth tells you quickly if it's the problem 6. If a tuning box or remap is fitted, return it to standard and see whether the code stays gone before you condemn t

Internal Control Module Keep Alive Memory (KAM) Error

Jump to the fix

Severity

Medium

Can I keep driving?

Usually drivable, but get it diagnosed without delay.

First step

A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training. 1. Load test the battery and check it properly. You want over 12.4V rested with the engine off and a steady 13.8 to 14.4V running. A battery that reads fine at rest but collapses under load is a classic cause of this code 2.

PPowertrain
0Generic code
6Computer Output
03Sequence number

What does it mean?

The engine control module in your car is a sophisticated computer responsible for controlling all the electronics concerned with vehicle operation. In addition to simply controlling things like ignition timing and fuel mix, on many modern vehicles, it also store information as you drive. It “learns” how you drive and can suit vehicle performance to match your specific needs and common conditions. This is referred to as the “Keep Alive Memory”, or KAM.

When the P0603 error is present the ECM is operating on it’s default parameters rather than the information stored via drive cycles. Note: It’s very common to see this code on vehicles, especially diesel trucks, when the owners have installed aftermarket engine management products. In these cases, the code can’t be repaired or cleared unless the aftermarket products are removed.

Symptoms

Likely causes

How to fix it

Codes From the Same System

All Fault Codes

Related Similar Codes

This information follows the generic OBD-II definition and does not replace a vehicle-specific diagnosis. The severity rating is rule-based; an authorised diagnostic reading is required for a definitive answer.