OBD Guide

B1845

Ignition Tamper Circuit Failure

B1845 is an OBD-II diagnostic trouble code meaning: Ignition Tamper Circuit Failure. Common causes: faulty ignition switch, damaged key or key chip. Estimated repair cost: $56–222.

Severity
🔴 High
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–222 (est.)

Symptoms

  • Engine won't start
  • The immobilizer indicator is flashing
  • The engine stalls immediately after starting
  • Loss of power to the ignition system

Causes

  • Faulty ignition switch
  • Damaged key or key chip
  • Open or short circuit in wiring harness
  • Corrosion of contacts in the ignition circuit
  • Faulty immobilizer module
  • Problems with the safety switch module

How to Fix

  1. Diagnostics of the ignition circuit with a multimeter
  2. Checking the status of the ignition key and its chip
  3. Inspect the wiring harness for damage
  4. Checking the contacts in the ignition switch
  5. Testing the immobilizer module
  6. Replacing faulty components

Related codes

FAQ

What does the B1845 code mean?

B1845 is an OBD-II diagnostic trouble code that indicates: Ignition Tamper Circuit Failure

What causes a B1845 error code?

The most common causes of B1845 include: Faulty ignition switch; Damaged key or key chip; Open or short circuit in wiring harness; Corrosion of contacts in the ignition circuit.

How do I fix a B1845 diagnostic trouble code?

To fix B1845: Diagnostics of the ignition circuit with a multimeter. Checking the status of the ignition key and its chip. Inspect the wiring harness for damage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1845?

Yes, but get it checked soon

How much does it cost to fix B1845?

The estimated repair cost for B1845 is $56–222. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat