OBD Guide

P3030

Disconnection Between Battery And ECU

P3030 is an OBD-II diagnostic trouble code meaning: Disconnection Between Battery And ECU. Common causes: broken ecu power wire, battery terminal oxidation. Estimated repair cost: $6–56.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$6–56 (est.)

Symptoms

  • The engine stalls or does not start
  • Reset ECU adaptations
  • Unstable engine operation
  • Lost connection with diagnostic equipment
  • Check Engine Light Is On

Causes

  • Broken ECU power wire
  • Battery terminal oxidation
  • Faulty main relay
  • Wiring harness damage
  • Poor contact in ECU connectors

How to Fix

  1. Check the condition of the battery terminals
  2. Check the integrity of the ECU power cable
  3. Check the operation of the main relay
  4. Inspect the ECU connectors for damage
  5. Check the integrity of the wiring harness

Related codes

FAQ

What does the P3030 code mean?

P3030 is an OBD-II diagnostic trouble code that indicates: Disconnection Between Battery And ECU

What causes a P3030 error code?

The most common causes of P3030 include: Broken ECU power wire; Battery terminal oxidation; Faulty main relay; Wiring harness damage.

How do I fix a P3030 diagnostic trouble code?

To fix P3030: Check the condition of the battery terminals. Check the integrity of the ECU power cable. Check the operation of the main relay. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P3030?

Do not drive — repair immediately

How much does it cost to fix P3030?

The estimated repair cost for P3030 is $6–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat