B0004 Code - Driver Knee Bolster Deployment Control
Quick Answer
The Restraints Control Module (RCM) monitors all deployable device and sensor circuits for a signal cross coupled (short) between circuits. Common causes include Faulty Driver Knee Airbag, Driver Knee Airbag harness is open or shorted, Driver Knee Airbag 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
- B0004 indicates Driver Knee Bolster Deployment Control.
- Common causes
- Common causes include Faulty Driver Knee Airbag, Driver Knee Airbag harness is open or shorted, Driver Knee Airbag 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.
Code B0004 Description
What are the Possible Causes of the DTC B0004?
- Faulty Driver Knee Airbag
- Driver Knee Airbag harness is open or shorted
- Driver Knee Airbag circuit poor electrical connection
How to Fix the DTC B0004?
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 B0004 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.
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Information for Specific Makes
- B0004 Ford — Driver Knee Bolster Deployment Control
- B0004 Lincoln — Driver Knee Bolster Deployment Control
- B0004 Mercury — Driver Knee Bolster Deployment Control
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.
Frequently Asked Questions about B0004 Code
1. What are common symptoms of OBDII code B0004?
- The common symptoms of OBDII code B0004 include the airbag warning light illuminating on the dashboard and a diagnostic trouble code related to the Driver Knee Bolster Deployment Control.
2. What does the OBDII code B0004 indicate?
- OBDII code B0004 indicates a problem with the Driver Knee Bolster Deployment Control system, which is responsible for deploying the knee airbag in the event of a collision.
3. What are possible causes of OBDII code B0004?
- Possible causes of OBDII code B0004 include a faulty Driver Knee Bolster Deployment Control module, wiring issues, or a problem with the knee airbag itself.
4. How can I diagnose the cause of OBDII code B0004?
- Diagnosing OBDII code B0004 involves using a diagnostic scanner to read the code, checking the wiring and connections to the Driver Knee Bolster Deployment Control module, and testing the functionality of the knee airbag.
5. What should I do if I encounter OBDII code B0004?
- If you encounter OBDII code B0004, it is recommended to have the issue diagnosed and repaired by a qualified technician to ensure the proper functioning of the Driver Knee Bolster Deployment Control system.
6. Can I drive my vehicle with OBDII code B0004?
- It is not recommended to drive your vehicle with OBDII code B0004 present, as it indicates a potential issue with the airbag system that could affect its ability to deploy in an accident.
7. How much does it cost to repair OBDII code B0004?
- The cost to repair OBDII code B0004 can vary depending on the underlying cause of the issue, with costs potentially ranging from a few hundred to a few thousand dollars.
8. Is OBDII code B0004 a common problem in vehicles?
- OBDII code B0004 is not as common as some other codes, but it can still occur in vehicles equipped with a Driver Knee Bolster Deployment Control system.
9. Can I reset OBDII code B0004 on my own?
- While you can clear the code using a diagnostic scanner, it is important to address the underlying issue causing OBDII code B0004 to prevent it from recurring.
10. How can I prevent OBDII code B0004 from appearing again?
- To prevent OBDII code B0004 from reappearing, it is essential to address any underlying issues promptly, perform regular maintenance on the airbag system, and avoid any physical damage to the knee airbag components.
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