P0603 6.0 Powerstroke

Ford has been informing users of the 6.0L engine’s condition, giving several Diagnostic Trouble Codes (DTC). One such DTC is P0603 6.0 Powerstroke, and it also carries its own meaning. Those experiencing this code can benefit from a discussion about symptoms to solving methods for assistance with the code.

What Does Code P0603 6.0 Powerstroke Mean?

P0603 is one of the most commonly encountered trouble codes for Ford’s 6.0L engine, with a definition that points to an Internal Control Module Keep Alive Memory (KAM) Error. The KAM functions as an AI-like system that learns from each drive cycle and includes settings altered while driving on different roads; it then supplies this data to the PCM in order to provide optimal performance according to user preferences. When these attempts fail after multiple tries, error code P0603 6.0 Powerstroke is generated. An interesting fact about the KAM is that it utilizes a special kind of RAM that permanently retains information due to being directly powered by the battery.

Symptoms Of Getting The P0603 Code On A 6.0 Powerstroke

Symptoms Of Getting The P0603 Code On A 6.0 Powerstroke
Symptoms Of Getting The P0603 Code On A 6.0 Powerstroke

Diagnostic Trouble Codes (DTCs) offer information on their presence through distinct symptoms. Should one experience the DTC P0603, it is likely due to the accompanying indications.

  • CEL (Check Engine Light) Is On
  • Engine Stalling Issue
  • The Engine Misfires Sometimes
  • The engine is Hard To Start
  • Rough Acceleration & Idling
  • Dramatically Increased Fuel Consumption 

It is important to note that these symptoms are not absolute. Investing in an OBD-II Code Scanner, which can be acquired for less than $50, may help confirm if the issue is a P0603 code.

The Causing Factors Of The Error Code P0603

This DTC is commonly caused by the use of aftermarket engine management products. Additionally, a variety of other factors can lead to the generation of error code P0603.

  • Keep Alive Memory is Not Receiving Enough Power
  • Battery or Keep Alive Memory Has Shorted Out
  • Loose Connection & Battery Terminal Corrosion
  • Malfunctioning Wiring Of Keep Alive Memory (KAM) & Keep Alive Power (KAPWR)
  • Damaged Keep Alive Memory or Powertrain Control Module
  • PCM Internal Fault Due To Water Intrusion
  • Faulty Battery & Charging System
  • How Serious Is The Code P0603 6.0 Powerstroke

This DTC P0603 can have varying effects on different engines, ranging from zero problems to potential damage. It is essential to investigate the issue and take appropriate steps for resolution; reading further in this article will provide more information on how best to proceed.

How To Solve P0603 Error Code On 6.0L Powerstroke?

P0603 is a Diagnostic Trouble Code (DTC) that can be diagnosed with simple DIY works. It is recommended to acquire the necessary equipment prior to troubleshooting this code.

  • A Battery Charger, Flashlight & Multimeter
  • An OBD-II Code Scanner

The equipment has been gathered. Therefore, the solution to the DTC P0603 can now be tackled. This article will provide a step-by-step guide on how to address this issue.

Wait Or Remove Aftermarket Engine Management Products

Engineering a truck with aftermarket engine management products is common among vehicle owners. It is possible that the installation of these products will trigger an error code P0603, which should not be a cause for alarm; in most cases, this code will clear itself out within a few days. If one desires to remove the code permanently, every aftermarket engine management product must be removed.

Check Your Battery Health

Using a car battery charger to fill the battery entirely is advised. After that, removing the code with a scanner tool will enable everyday driving for about one week. If DTC reappears, it suggests that the battery does not have enough power to keep the memory alive while charged by the truck itself. Replacing both the battery and wiring should solve this issue permanently; otherwise, replacing the wiring can be done as a second attempt.

Inspect Battery Related Wiring

It is suggested to check battery cables thoroughly for damage, corrosion, and loose connections. Replacing the wiring should solve the battery issue if any of these are found.

Check For PCM Wiring Leakage

The PCM wiring's role in generating an error code should not be underestimated. To check if the power supply line is providing enough voltage (12.5V) to the PCM, one must bend the wire and observe if a voltage change indicates a broken or loose connection. If this is the case, replacing the power supply line should resolve any existing error codes.

Update To The Latest PCM Software Version

Manufacturers oftentimes release PCM software updates without wide recognition in the beginning. Operating on outdated/older software can lead to the P0603 error code. To avoid this issue, it is recommended to visit a dealer and update to the most current PCM software version; with that done, the chances of seeing this error code diminish greatly.

Replace Your Powertrain Control Module (Rare Case)

When dealing with a Ford 6.0L engine, diagnosing the PCM as the main culprit is crucial when everything else seems to be working correctly, but still, an error code P0603 persists. Replacing the PCM generates positive results and should only be done by a professional who can charge according to their hourly rate. To save some money, one should purchase the PCM on their own instead of relying on professionals for that too.

How Much Does The DTC P0603 Cost To Solve?

Fixing the DTC P0603 is subject to the method of repair. If an essential wire replacement is chosen, costs should not exceed $50; however, when replacing the battery, one can expect to spend around $200. The most costly solution would be PCM replacement which can range from $500 up to $1500 with an additional labor cost of $250.

Common Mistakes While Solving The P0603 Code

Attempting to solve the P0603 error code without first gathering information on the issue can be a mistake. Doing so could potentially lead to further complications as one might not be aware of all the nuances that come with Ford's 6.0L engine.

  • Reading The Voltage Wrong While Testing The Power Supply Line
  • Not Testing Everything (Wirings, Connectors & Harness) Before Testing & Replacing The PCM. 

When a truck's battery has been recently disconnected, it is typical for the Diagnostic Trouble Code (DTC) to be displayed. This code should disappear on its own after a few days; however, if this does not occur, then the tips offered in the article should be followed to ensure that the wallet and engine remain safe and healthy.


This article was written as a comprehensive guide for understanding DTC P0603. Knowledge of this error code is essential to quickly and accurately spot and diagnose the problem, thereby avoiding further damage to your 6.0L Powerstroke engine. While it may be possible to figure out what’s causing the issue on one’s own, professional help should not be overlooked when needed; any hesitance due to higher hourly rates can prove more costly in the long run if damages persist without proper treatment.

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