← Back to Search Severity: High

B0078

B0078: Immobilizer System Malfunction

Fix Cost
$100 - $500
Est. parts cost
Labor Cost
$100 - $300
Mechanic rates
Difficulty
3/5
Moderate
1-2 hours
DIY Fix?
❌ No
See mechanic

📖 What Does B0078 Mean?

The immobilizer system has malfunctioned, preventing the vehicle from starting or running. This code indicates a problem with the immobilizer system's communication with the engine control module.

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Symptoms

Vehicle will not start, or will start and then stall, or will not run due to immobilizer system malfunction

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Common Causes

Faulty immobilizer key fob, faulty immobilizer system module, faulty wiring or connectors, software issue

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Possible Solutions

1. Check the immobilizer key fob's battery level and replace if necessary. 2. Check the immobilizer system module for any signs of physical damage or corrosion. 3. Inspect and clean the wiring and connectors for any signs of damage or corrosion. 4. Update the vehicle's software if necessary. 5. Replace the immobilizer system module if none of the above steps resolve the issue.

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Recommended Parts & Tools

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Frequently Asked Questions about B0078

How serious is B0078?

This code has a high severity level. You should address this issue immediately to prevent engine damage.

Can I drive with B0078?

Driving with this code is not recommended as it may cause further engine damage.

How much does it cost to fix B0078?

Repair costs vary depending on the root cause, but typically range from $200-500 including parts and labor.

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Related Diagnostic Codes

Other codes that may appear with B0078

💡 Why These Codes Are Related:

  • Similar Issues: Same root cause or component failure
  • Related Problems: Often occur together due to system interactions
  • Sequential Codes: Progressive failure stages or multiple sensors
  • Same System: Components within the same automotive system