OBD Guide
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U1601

ECU Application Software Code 1 Missing Or Corrupted

U1601 is an OBD-II diagnostic trouble code meaning: ECU Application Software Code 1 Missing Or Corrupted. Common causes: ecu firmware update failed, ecu memory damage. Estimated repair cost: $56–333.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–333 (est.)

Symptoms

  • Engine won't start
  • Unstable engine operation
  • Check Engine light comes on
  • Power Loss
  • Failure of other vehicle systems

Causes

  • ECU firmware update failed
  • ECU memory damage
  • Power supply problems during programming
  • Errors when flashing the ECU
  • Physical damage to the ECU

How to Fix

  1. Check the condition of the computer
  2. Try to reflash the ECU
  3. Check ECU power supply
  4. Replace the ECU if necessary
  5. Contact an Automotive Electronics Specialist

Related codes

U1600U1602U1603

FAQ

What does the U1601 code mean?

U1601 is an OBD-II diagnostic trouble code that indicates: ECU Application Software Code 1 Missing Or Corrupted

What causes a U1601 error code?

The most common causes of U1601 include: ECU firmware update failed; ECU memory damage; Power supply problems during programming; Errors when flashing the ECU.

How do I fix a U1601 diagnostic trouble code?

To fix U1601: Check the condition of the computer. Try to reflash the ECU. Check ECU power supply. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1601?

Do not drive — repair immediately

How much does it cost to fix U1601?

The estimated repair cost for U1601 is $56–333. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat