B1205 Code - Diagnosis Sensor Unit

Quick Answer

The B1205 diagnostic trouble code (DTC) refers to an issue with the Diagnosis Sensor Unit in a vehicle's system. Common causes include Electrical issues such as wiring harness damage or corrosion, Sensor malfunctions leading to inaccurate data, Exposure to extreme temperatures causing electronic component failure. 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 Electrical issues such as wiring harness damage or corrosion, Sensor malfunctions leading to inaccurate data, Exposure to extreme temperatures causing electronic component failure.

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.

• Description
• Common Causes
• Symptoms
• How To Fix
• Cost to Fix
• FAQs
• Comments
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Common Causes of B1205

Symptoms of B1205

How to Fix B1205

Cost to Fix B1205

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Code B1205 Information for Specific Makes

• B1205 Ford — EIC Switch Assembly Circuit Failure
• B1205 Infiniti — Diagnosis Sensor Unit
• B1205 Lincoln — EIC Switch Assembly Circuit Failure
• B1205 Mercury — EIC Switch Assembly Circuit Failure
• B1205 Nissan — Diagnosis Sensor Unit

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.