P1639Manufacturer-specific code

P1639 Code: Vehicle ID Block Corrupted or Not Programmed (Ford)

On Ford, Lincoln and Mercury vehicles, the P1639 code means the vehicle identification block is corrupted or was never programmed. The speedometer may read wrong. It almost always follows a computer replacement that was not configured.

Severity
Medium
Can I keep driving?
Yes, but with caution
Estimated cost
$50 to $250
Difficulty
Hard
System
Computer and Outputs
Applies to
Depends on the manufacturer

Common in: Ford

Updated Reviewed by Renzo Chacca

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What the P1639 code means

P1639 is a manufacturer-specific code: the 1 in the second position means each automaker defines what it means, not the generic SAE standard. The most widespread definition is the one used by Ford, Lincoln and Mercury. If your vehicle is another brand, confirm the code text with a scan tool that supports that manufacturer.

ManufacturerMeaning of P1639
Ford, Lincoln and MercuryVehicle ID block corrupted or not programmed

The computer on many Fords stores a vehicle identification (VID) block with the tire size, the axle ratio and other configuration data.

The P1639 code appears when that block is empty or corrupted, almost always after the computer was replaced without being configured. It can cause wrong shifting or an incorrect speedometer reading.

Before you start repairs, confirm the make, model, year and engine. With manufacturer codes, the same number can change even between engines from the same brand.

P1639 code symptoms

  • Check engine light on.
  • Incorrect speedometer reading.
  • Odd shifting.

Likely causes of the P1639 code

  1. New or used computer not configured. This is uncommon, so rule out everything else first.
  2. Interrupted programming. Confirm it with the tests in the diagnosis section.

How to diagnose the P1639 code step by step

  1. Find out whether the computer was replaced.
  2. Read the VID block with the scan tool.

How to fix the P1639 code

  • Program the identification block with the right equipment.

Technical reference data

  • It requires a scan tool with Ford programming functions.
  • P1xxx codes are manufacturer-specific: confirm the definition with a scan tool that supports your brand.
  • Reference values: check the manufacturer data for your vehicle.

Brand-specific notes

A speedometer that reads off after a computer swap is the classic sign. The fix is configuration, not another part.

P1639 on Ford

Common on the Focus, Fiesta, Escape, Explorer, Ranger, F-150 and Mustang.

If your vehicle is another brand, check the table above for the meaning its manufacturer gives this code and confirm it with a compatible scan tool.

Frequently asked questions about P1639

What does the P1639 code mean on a Ford?
It means the vehicle identification block is corrupted or was never programmed. The speedometer may read incorrectly.
Does P1639 mean the same thing on every brand?
No. It is a manufacturer-specific code, so on other brands it may not exist or may mean something different. Confirm it with a scan tool that supports your make.
Can I drive with a P1639 code?
With caution. A P1639 code can bring a wrong speedometer and odd shifting, so watch your real speed and get it programmed soon.
How much does it cost to fix P1639?
Roughly $50 to $250 on a Ford. The cost is mostly the programming service with the right scan tool.
Will a P1639 code clear itself?
No. The block stays empty or corrupted until it is programmed again.
What is the most common cause of P1639?
A new or used computer that was installed without being configured. An interrupted programming session is the other possibility.

Related codes

Questions about the P1639 code

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