P0602Generic code

P0602 Code: Control Module Programming Error

The P0602 code means the computer is not programmed, or its programming is incomplete. It is normally solved by programming or configuring the module with the right equipment. Check the power supply and grounds before you condemn the computer.

Severity
Medium
Can I keep driving?
Yes, but with caution
Estimated cost
$0 to $1,500
Difficulty
Hard
System
Computer and Outputs
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P0602 code means

The P0602 code usually shows up after the computer was replaced with a new one or one from another vehicle, or after a reprogramming that was interrupted (for example, because the battery went flat during the process).

Before you decide the computer is bad, always check its power supply and grounds. Low voltage, a loose terminal or a corroded ground cause internal errors that go away once they are corrected. It is also worth looking for software updates from the manufacturer, because many of these codes are resolved by reprogramming the computer without replacing it.

If the computer has to be replaced, keep in mind that it almost always needs programming: VIN, immobilizer, option configuration and, on many vehicles, relearn procedures afterward. A used computer that has not been programmed can leave the vehicle unable to start.

P0602 code symptoms

  • Check engine light on.
  • The engine may not start or may run in limp mode.
  • Other codes at the same time in several systems.

Likely causes of the P0602 code

  1. Computer not programmed or configured wrong after it was replaced.
  2. Programming interrupted by a lack of voltage during the process.
  3. Wrong computer from another vehicle or another version.

How to diagnose the P0602 code step by step

  1. Clear the code and see whether it comes back. Some are caused by a one-time event, such as a discharged battery.
  2. Measure the voltage at the computer power pins and compare it with the battery.
  3. Measure the voltage drop on the grounds. It should be under 0.1 V with a load.
  4. Look for technical service bulletins and software updates.
  5. Inspect the computer connector for moisture, corrosion or bent pins.

How to fix the P0602 code

  • Correct the power supply and the grounds.
  • Reprogram or update the computer.
  • Configure or program the VIN, options and keys if that applies.
  • Clear the codes and verify.

Technical reference data

  • Supply voltage: battery voltage, with less than 0.2 V of drop.
  • Programming needs a stable voltage, so use a battery maintainer.
  • Reference values only: check the manufacturer data for your vehicle.

Brand-specific notes

Manufacturers publish software updates that fix many of these codes. Check with the dealer before you replace the computer.

P0602 on Ford

Software updates have fixed related codes such as P0606 on Ford vehicles.

P0602 on Chrysler

Software updates have fixed related codes such as P0606 on Chrysler vehicles.

P0602 on Hyundai

Software updates have fixed related codes such as P0606 on Hyundai vehicles.

Frequently asked questions about P0602

Can I drive with the P0602 code?
It depends on the symptoms. If the engine runs normally, drive with caution. If it goes into limp mode, take the vehicle to a shop.
Does the computer have to be replaced?
Not always. Many times it is the power supply, a ground or the software.
Does a used computer work?
Only if it is programmed correctly for your vehicle.
How much does it cost to fix P0602?
From $0 (if it was the battery) up to $1,500 if the computer has to be replaced and programmed.
What does the P0602 code mean?
The P0602 code is a generic OBD2 code for a control module programming error. The computer is not programmed, or the programming is incomplete.
What is the most common cause of P0602?
A computer that was just replaced and never programmed, or a reprogramming that was interrupted by a voltage drop.

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Questions about the P0602 code

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