OBD Guide

B1846

Ignition Tamper Circuit Open

B1846 is an OBD-II diagnostic trouble code meaning: Ignition Tamper Circuit Open. Common causes: open or short circuit in wiring harness, faulty ignition switch. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Engine won't start
  • The immobilizer indicator is flashing
  • Recording a fault code in the ECU memory

Causes

  • Open or short circuit in wiring harness
  • Faulty ignition switch
  • Problems with the immobilizer module
  • Damaged contacts or connectors

How to Fix

  1. Check the integrity of the wiring harness in the immobilizer circuit
  2. Inspect connectors and contacts for corrosion or damage
  3. Check the operation of the ignition switch
  4. Diagnose the immobilizer module
  5. If necessary, replace faulty components

Related codes

FAQ

What does the B1846 code mean?

B1846 is an OBD-II diagnostic trouble code that indicates: Ignition Tamper Circuit Open

What causes a B1846 error code?

The most common causes of B1846 include: Open or short circuit in wiring harness; Faulty ignition switch; Problems with the immobilizer module; Damaged contacts or connectors.

How do I fix a B1846 diagnostic trouble code?

To fix B1846: Check the integrity of the wiring harness in the immobilizer circuit. Inspect connectors and contacts for corrosion or damage. Check the operation of the ignition switch. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1846?

Limited driving only, diagnose soon

How much does it cost to fix B1846?

The estimated repair cost for B1846 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat