AutoCodesGeneric – B1205

B1205 Code - Diagnosis Sensor Unit

Quick Answer

The Air Bag Diagnosis Sensor Unit detects the whole SRS electrical system and displays the malfunction either by illuminating or blinking the air bag warning lamp in the combination meter. Common causes include Faulty Diagnosis Sensor Unit, Diagnosis Sensor Unit harness is open or shorted, Diagnosis Sensor Unit circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
B1205 indicates Diagnosis Sensor Unit.
Common causes
Common causes include Faulty Diagnosis Sensor Unit, Diagnosis Sensor Unit harness is open or shorted, Diagnosis Sensor Unit circuit poor electrical connection.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 24,560
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Nov 19, 2024
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Code B1205 Description

The Air Bag Diagnosis Sensor Unit detects the whole SRS electrical system and displays the malfunction either by illuminating or blinking the air bag warning lamp in the combination meter. The Air Bag Diagnosis Sensor Unit detects a shock that exceeds specified level and watches such systems as the driver and passenger air bag, side air bag, curtain air bag, pre-tensioner seat belts and Occupant Classification System (OCS) operate properly.
The Air Bag Diagnosis Sensor Unit contains the “G” sensors for both frontal and side collisions and spare battery function in case of main battery damaged in a collision.
OBDII Code B1205 - Diagnosis Sensor Unit - AutoCodes.com
B1205 Code - Diagnosis Sensor Unit

What are the Possible Causes of the DTC B1205?

  • Faulty Diagnosis Sensor Unit
  • Diagnosis Sensor Unit harness is open or shorted
  • Diagnosis Sensor Unit circuit poor electrical connection

How to Fix the DTC B1205?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B1205 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B1205 code?

Need more information on how to fix the B1205 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1205 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service

  • Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
  • Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
  • Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
  • Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.

Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B1205 Code

1. What does the OBDII code B1205 mean?

Code B1205 indicates an issue with the Diagnosis Sensor Unit (DSU), which is typically part of the airbag or supplemental restraint system (SRS).

2. What are the common symptoms of code B1205?

Common symptoms include the airbag warning light staying illuminated, a malfunctioning airbag system, or stored fault codes related to the SRS.

3. What causes the B1205 code to appear?

The B1205 code can be triggered by faulty wiring, a malfunctioning diagnosis sensor unit, poor connections, or physical damage to the DSU.

4. Can I drive my vehicle with the B1205 code active?

While the car may still be drivable, the airbag system may not function properly, posing a safety risk in the event of an accident.

5. How is the B1205 code diagnosed?

A technician will use a scan tool to confirm the code, inspect the DSU and related wiring for damage or loose connections, and check for other SRS-related fault codes.

6. What repairs are needed to fix the B1205 code?

Repairs may include replacing the diagnosis sensor unit, repairing or replacing damaged wiring, or ensuring all connectors are secure and corrosion-free.

7. How much does it cost to fix the B1205 code?

Repair costs vary depending on the vehicle, but diagnosis sensor unit replacement can range from $200 to $600, excluding labor.

8. Can clearing the B1205 code fix the issue?

Clearing the code may temporarily turn off the warning light, but the underlying issue must be addressed to prevent the code from returning.

9. What tools are needed to diagnose and repair code B1205?

You’ll need an OBDII scanner, a multimeter for testing wiring and connections, and possibly specialized tools to access and replace the DSU.

10. Is the B1205 code specific to any vehicle make or model?

While the code can appear on various vehicles, its meaning and repair process may vary slightly depending on the manufacturer’s design of the airbag system. Always refer to the vehicle’s service manual for specifics.

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