OBD Guide
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P0603

Internal Control Module Keep Alive Memory (KAM) Error

P0603 is an OBD-II diagnostic trouble code meaning: Internal Control Module Keep Alive Memory (KAM) Error. Common causes: physical damage to the eeprom chip in the ecu, weak battery (kam loses data when voltage is low). Estimated repair cost: $89–556.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$89–556 (est.)

Symptoms

  • Unstable engine operation immediately after starting (especially cold)
  • Unstable idle before warming up
  • The engine behaves like it was just trained every time
  • Check Engine Light Is On
  • Rich or lean mixture until adaptation is complete

Causes

  • Physical damage to the EEPROM chip in the ECU
  • Weak battery (KAM loses data when voltage is low)
  • Poor contact in the ECU constant power supply circuit (+12V constant terminal)
  • Unstable ECU ground
  • Effect of electrostatic discharge on the ECU

How to Fix

  1. Check battery voltage and charge if necessary
  2. Check the constant power terminal of the ECU (should be 12V even with the ignition off)
  3. Check all ground points of the ECU for reliable contact.
  4. Try to reprogram the ECU with official software
  5. Diagnose the physical condition of the ECU for damage to the board
  6. Replace or repair the ECU (resoldering the EEPROM chip)

Related codes

P0600P0601P0602P0604P0605

Error P0603 by Vehicle Brand

AcuraAudiBAICBMWBYDBuickCadillacChanganCheryChevroletChryslerCitroenDodgeDongfengExeedFAWFordForthingFotonGACGMGMCGeelyGreat WallHavalHondaHongqiHyundaiInfinitiJACJaecooJaguarJeepJetourKaiyiKiaLadaLexusLi AutoLifanLincolnLivanMazdaMercedes-BenzMercuryMitsubishiNIONissanOldsmobileOmodaOpelPeugeotPlymouthPontiacRenaultSWMSaturnSkodaSkywellSubaruSuzukiTankToyotaVolkswagenVolvoVoyahXPengZeekrZotye

FAQ

What does the P0603 code mean?

P0603 is an OBD-II diagnostic trouble code that indicates: Internal Control Module Keep Alive Memory (KAM) Error

What causes a P0603 error code?

The most common causes of P0603 include: Physical damage to the EEPROM chip in the ECU; Weak battery (KAM loses data when voltage is low); Poor contact in the ECU constant power supply circuit (+12V constant terminal); Unstable ECU ground.

How do I fix a P0603 diagnostic trouble code?

To fix P0603: Check battery voltage and charge if necessary. Check the constant power terminal of the ECU (should be 12V even with the ignition off). Check all ground points of the ECU for reliable contact.. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0603?

Do not drive — repair immediately

How much does it cost to fix P0603?

The estimated repair cost for P0603 is $89–556. Actual cost depends on your vehicle, location, and labor rates.

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