B1999 OBD-II Trouble Code: Passenger Side Side-Mount Air Bag Low Resistance on Squib

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE B1999 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the B1999 code

B1999 is a diagnostic trouble code (DTC) for "Passenger Side Side-Mount Air Bag Low Resistance on Squib". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $79.99. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$79.99$20.00
Toyota$79.99$20.00
BMW$79.99$20.00
SCHEDULE B1999 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light

B1999 code definition

The B1999 trouble code detects a side mount air bag inflation circuit error on the passenger side.

What the B1999 code means

The B1999 code is a standard OBD-II trouble code that signals a circuit malfunction in the side mount air bag inflator for the passenger seat. The side mount air bag is placed on the passenger side B-pillar, and inflates when the car is in an accident to provide protection for the passenger. Whenever the air bag control module, body control module, or powertrain control module (PCM) detect an abnormal or insufficient voltage reading from the side mount air bag inflator circuit on the passenger side, the B1999 trouble code may be triggered.

What causes the B1999 code?

The B1999 trouble code is usually caused by damaged or defective electrical components, such as blown fuses, open or loose connectors, or, most commonly, shorted wires. These damaged electrical components may be in the side mount air bag inflator, in the general side mount air bag system, or in the air bag control module. The code is also commonly caused by a defective squib, which is the component responsible for beginning the air bag inflation process, or a broken clockspring. Less common, but also possible, is a defective air bag control module. Finally, the code may also be triggered by a faulty PCM or body control module, though this is extremely rare.

What are the symptoms of the B1999 code?

If the B1999 code has been detected, it is likely that the side mount air bag on the passenger side will fail to inflate in the event of a crash. It is also possible that the entire air bag system will be inoperable, and no air bags will deflate should an accident occur. This code is commonly accompanied by an illuminated check engine soon Warning Light and air bag Warning Light on the gauge cluster.

How does a mechanic diagnose the B1999 code?

The B1999 code will be diagnosed using a general OBD-II trouble code scanner. A trustworthy mechanic will use the scanner to view the freeze frame data and gather information about the code. The scanner will also be utilized to see if there are any other trouble codes present. If numerous codes are detected, they will need to be diagnosed in the order that they appear in. The trouble codes will then be reset, the vehicle restarted, and the presence of the B1999 code checked for. If the code is no longer present, then it was likely detected erroneously, or was caused by an intermittent problem.

If the code remains detected, then the mechanic will begin by thoroughly inspecting all of the electrical components in the air bag system, particularly in the side mount air bag circuit and inflator. All damaged or compromised parts should be replaced. The squib should then be closely inspected, followed by the clockspring. If the problem has not yet been identified, a deeper inspection of the air bag control module will follow.

After the mechanic replaces or repairs any parts, the inspection should be paused while the codes are reset, the vehicle restarted, and the B1999 code checked for. By doing this, the technician will be informed as soon as the issue is resolved.

Common mistakes when diagnosing the B1999 code

The most frequently made mistake when diagnosing this code comes from a failure to properly adhere to the OBD-II trouble code diagnosis protocol. The protocol should be observed at all times, to increase the chances of an accurate and efficient diagnosis and repair.

It is fairly common for damaged wires to be overlooked, which often leads to unnecessary repairs of the side mount air bag squib, or the air bag control module.

How serious is the B1999 code?

A vehicle with the B1999 code will be drivable, and will not experience drivability problems. The side mount air bag on the passenger side will likely fail to inflate in an accident, however, and it is very possible that all of the air bags will experience failure. The air bag system is one of the most crucial safety features in the vehicle, and can save the life of the driver and passengers. Because of this, a vehicle with this code should not be driven until it has been inspected.

What repairs can fix the B1999 code?

Repairs for the B1999 trouble code are:

  • Replacement of wires, connectors, and fuses
  • Replacement of the side mount air bag squib
  • Replacement of the clockspring
  • In rare cases, replacement of the air bag control module
  • In very rare cases, replacement of the body control module or PCM

Additional comments for consideration regarding the B1999 code

This code is a manufacturer specific code, which means that the definition can vary based on the automaker. While the B1999 trouble code notes a side mount air bag circuit error in many cars, it can represent an entirely different body issue for other manufacturers. As always, the mechanic should be cognizant of the vehicle that is being inspected when diagnosing the B1999 code.

Need help with a B1999 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

air bags
B1998
trouble codes
Check Engine Light

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE B1999 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

4,255

Rating Summary
3,898
174
45
26
112
3,898
174
45
26
112
Ben

Ben

39 years of experience
1020 reviews
Ben
39 years of experience
Lexus LS430 - Check Engine Light is on - Houston, Texas
I was very pleased with the courtesy and work of Mr. Smith. He was exceptional in explaining and correcting the problem and thereby gained my trustI . I request he be my mechanic in all future service requests. I had a great experience working with Mr. Ben Smith.
Richard

Richard

19 years of experience
203 reviews
Richard
19 years of experience
Ram ProMaster 1500 - Check Engine Light is on - Bonita Springs, Florida
Prompt, polite and personal. Took the time to explain the process and his recommendations. 2 thumbs up
Michael

Michael

23 years of experience
37 reviews
Michael
23 years of experience
Ford F-150 - Check Engine Light is on - Federal Way, Washington
Very helpful and explained everything and what needs to be addressed. I feel informed and confident in Mike’s assessment and look forward to him performing services on my vehicle.
Rigoberto

Rigoberto

9 years of experience
650 reviews
Rigoberto
9 years of experience
Honda Civic - Check Engine Light is on - Chicago, Illinois
Rigoberto came on time & quickly diagnosed the problem- rats chewed thru wiring near the battery. He wasn’t able to fix it himself bc of parts, but gave me recommendations on where to go & how to not have the dealership sell me services that are not needed.

More related articles

How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...

Related questions

Q: How many airbags does my car have, and where are they located?

Your vehicle has six airbags: frontal airbags for both the driver and the front passenger; seat-mounted side impact airbags for both the driver and the front passenger; and roof-rail airbags behind both front seats, to protect both rows of seating....

Q: Car jerking with flashing check engine light.

If your Check Engine Light is flashing, you need to stop driving it until it is fixed. A flashing Check Engine Light is warning you that there is a fire danger because there is to much raw fuel entering the...

Q: Issue with throttle position sensor and Check Engine light is on.

I'm not quite sure what to make of this description, but I'm guessing you are trying to say the check engine light goes off and on intermittently with a code stored for the throttle position sensor (TPS). I do not...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com