OBD Guide
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U1253

Invalid Or Missing Data For Class A Functions

U1253 is an OBD-II diagnostic trouble code meaning: Invalid Or Missing Data For Class A Functions. Common causes: open or short circuit in class a bus circuit, fault in one of the modules connected to the bus. Estimated repair cost: $6–167.

Severity
✅ Low
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$6–167 (est.)

Symptoms

  • Incorrect operation of secondary systems (climate control, audio system)
  • Check Engine Light Illuminates
  • Lack of communication with some modules during diagnostics
  • Intermittent electrical failures

Causes

  • Open or short circuit in class A bus circuit
  • Fault in one of the modules connected to the bus
  • Poor contact in connectors
  • Problems with the module software
  • Contact corrosion

How to Fix

  1. Check the integrity of the class A bus wiring
  2. Inspect connectors for oxidation or damage
  3. Carry out diagnostics of modules connected to the bus
  4. Update the software of the problematic module
  5. If necessary, replace the faulty module

Related codes

U1251U1255U1262

FAQ

What does the U1253 code mean?

U1253 is an OBD-II diagnostic trouble code that indicates: Invalid Or Missing Data For Class A Functions

What causes a U1253 error code?

The most common causes of U1253 include: Open or short circuit in class A bus circuit; Fault in one of the modules connected to the bus; Poor contact in connectors; Problems with the module software.

How do I fix a U1253 diagnostic trouble code?

To fix U1253: Check the integrity of the class A bus wiring. Inspect connectors for oxidation or damage. Carry out diagnostics of modules connected to the bus. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1253?

Yes, but get it checked soon

How much does it cost to fix U1253?

The estimated repair cost for U1253 is $6–167. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat