B1858 Toyota Code - Short To Positive In Rear Side Squib Left Circuit
Quick Answer
The Rear Side Squib Left (LH) Circuit consists of the Center Airbag Sensor Assembly and the Rear Seat Side Airbag Assembly Left (LH). Common causes include Faulty Rear Seat Side Airbag Assembly Left (LH) (Rear Side Squib Left Circuit), Rear Seat Side Airbag Assembly Left harness is open or shorted, Rear Seat Side Airbag Assembly Left 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
- B1858 Toyota indicates Short To Positive In Rear Side Squib Left Circuit.
- Common causes
- Common causes include Faulty Rear Seat Side Airbag Assembly Left (LH) (Rear Side Squib Left Circuit), Rear Seat Side Airbag Assembly Left harness is open or shorted, Rear Seat Side Airbag Assembly Left 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 B1858 Toyota Description
What are the Possible Causes of the DTC B1858 Toyota?
- Faulty Rear Seat Side Airbag Assembly Left (LH) (Rear Side Squib Left Circuit)
- Rear Seat Side Airbag Assembly Left harness is open or shorted
- Rear Seat Side Airbag Assembly Left circuit poor electrical connection
- Faulty Center Airbag Sensor Assembly
How to Fix the DTC B1858 Toyota?
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 B1858 Toyota 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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Need Help with the Code?
Get the B1858 Toyota code diagnosed by a professional: Find a repair shop in your area
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 B1858 Toyota Code
1. What does the OBDII code B1858 mean on a Toyota?
The B1858 code indicates a "Short to Positive in Rear Side Squib Left Circuit," which relates to the airbag system's wiring or components on the left rear side.
2. What are the common symptoms of the B1858 code?
Symptoms may include the airbag warning light illuminating, the airbag system being disabled, and no noticeable effects on vehicle performance.
3. What causes the B1858 code to appear on a Toyota?
This code is typically caused by a short circuit in the wiring of the left rear side airbag, damaged connectors, a faulty airbag module, or corrosion in the circuit.
4. Is it safe to drive with the B1858 code active?
Driving with this code may not affect normal operation, but the airbag system may not function properly in an accident, making it unsafe.
5. How is the B1858 code diagnosed?
A technician will inspect the airbag wiring and connectors, check for shorts or damage, and use a scan tool to verify the fault and clear the code after repairs.
6. Can I fix the B1858 code myself?
If you are experienced with automotive electrical systems, you can inspect the wiring and connections, but airbag systems are sensitive and should ideally be handled by a professional.
7. How much does it cost to repair the B1858 code on a Toyota?
The repair cost can vary, typically ranging from $100 to $500, depending on whether wiring repairs, connector replacements, or a new airbag module are required.
8. Can a blown fuse cause the B1858 code?
While a blown fuse is unlikely to directly cause this code, a fuse issue can sometimes indicate an underlying electrical problem that might contribute to it.
9. Will resetting the code fix the B1858 issue?
Resetting the code without addressing the root cause will not fix the problem, and the code is likely to reappear.
10. Can extreme weather trigger the B1858 code?
Extreme weather, such as high humidity or temperature fluctuations, can sometimes exacerbate wiring issues or cause corrosion, potentially triggering this code.
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