OBD Guide

B0997

Auxiliary Electronic Control Unit Performance

B0997 is an OBD-II diagnostic trouble code meaning: Auxiliary Electronic Control Unit Performance. Common causes: malfunction of the auxiliary control unit, problems with wiring harness or connections. Estimated repair cost: $56–222.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–222 (est.)

Symptoms

  • Check Engine light comes on
  • Reduced efficiency of connected systems
  • Incorrect operation of auxiliary functions (for example, climate control, airbags)

Causes

  • Malfunction of the auxiliary control unit
  • Problems with wiring harness or connections
  • Software errors in the control unit
  • Short circuit or open circuit

How to Fix

  1. Carry out diagnostics using an OBD-II scanner to clarify the problem
  2. Check the integrity of the wiring harness and connections
  3. Update or reflash the control unit software
  4. If necessary, replace the faulty control unit

Related codes

Error B0997 by Vehicle Brand

FAQ

What does the B0997 code mean?

B0997 is an OBD-II diagnostic trouble code that indicates: Auxiliary Electronic Control Unit Performance

What causes a B0997 error code?

The most common causes of B0997 include: Malfunction of the auxiliary control unit; Problems with wiring harness or connections; Software errors in the control unit; Short circuit or open circuit.

How do I fix a B0997 diagnostic trouble code?

To fix B0997: Carry out diagnostics using an OBD-II scanner to clarify the problem. Check the integrity of the wiring harness and connections. Update or reflash the control unit software. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B0997?

Limited driving only, diagnose soon

How much does it cost to fix B0997?

The estimated repair cost for B0997 is $56–222. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat