B1924 — Air Bag Internal Diagnostic Monitor Fault or System Disarm Fault

OBD2 code B1924 flags a problem with the airbag / restraint system (SRS) (air bag internal diagnostic monitor fault or system disarm fault). Short, gentle driving to a shop is usually possible. Common culprits: depleted backup battery or low system voltage, faulty impact or occupancy sensor, failed clockspring (driver airbag circuit).

body electrical

Is it safe to drive?

Drive with caution The car drives normally, but with the SRS light on the airbags may not deploy in a crash. Treat it as a safety-critical repair: fine to drive to the shop, not fine to ignore for months.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm B1924 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many B0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the airbag / restraint system (SRS) for damage, corrosion, chafing or poor contact.
Subsystem check Read the SRS module with a scanner that supports airbag systems — generic OBD2 readers cannot see these codes.
Subsystem check Inspect under-seat connectors — they are often disturbed by seat movement or cleaning.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm B1924 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1924 (parts and labor, USD, independent shop rates): SRS module reset or replacement: $300–$1,000; Replace a sensor or clockspring: $150–$500; Reconnect or repair SRS wiring/connectors: $80–$250. Overall, fixing B1924 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What does OBD2 code B1924 mean?

Will B1924 clear itself?

Sometimes B1924 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What is the most common cause of B1924?

The most common causes are: depleted backup battery or low system voltage, faulty impact or occupancy sensor, failed clockspring (driver airbag circuit).

Is it safe to drive with B1924?

The car drives normally, but with the SRS light on the airbags may not deploy in a crash. Treat it as a safety-critical repair: fine to drive to the shop, not fine to ignore for months.

What are the symptoms of B1924?

Drivers most often notice: airbag system disabled message, airbag (SRS) warning light on, no other driving symptoms.

B1924 — Air Bag Internal Diagnostic Monitor Fault Or System Disarm Fault: Causes, Symptoms & Fix

The B1924 OBD2 fault code relates to the Air Bag Internal Diagnostic Monitor Fault Or System Disarm Fault circuit. When the circuit circuit failure, the module cannot properly monitor or control this body system.

At AIscanAuto, we help drivers quickly identify OBD2 trouble codes, understand their root causes, and find the right fix.

Symptoms

Airbag / SRS warning light illuminated
Seatbelt tensioner may not function
Possible warning chime
Safety system deactivated

Common Causes

Faulty component — internal damage or wear affecting Air Bag Internal Diagnostic Monitor Fault Or System Disarm Fault
Wiring issues — broken, corroded, or chafed wires in the circuit
Connector problems — loose, oxidized, or moisture-damaged pins
a general circuit failure is detected — can result from wiring faults, connector issues, or component failure
Module input failure — rare, but the control module input stage may be defective

Step-by-Step Diagnosis

Scan with OBD2 tool — Confirm B1924 is active. Check for additional DTCs.
Visual inspection — Examine the Air Bag Internal Diagnostic Monitor Fault Or System Disarm Fault wiring and connector for corrosion or damage.
Check voltage and ground — Use a multimeter to verify proper reference voltage.
Test component — Compare readings to factory specs. A stuck or erratic signal confirms failure.
Check for shorts/opens — Perform continuity tests on the wiring between the component and control module.

Repair & Solutions

If the component is defective, replace the Air Bag Internal Diagnostic Monitor Fault Or System Disarm Fault with an OEM or quality aftermarket part.
Repair any damaged wiring or connectors using proper methods.
Clear the DTC with an OBD2 scanner and test drive to verify the code does not return.
If the code persists after component replacement, inspect the control module connector.

Related Codes

B1921 — Air Bag Diagnostic Monitor Ground Circuit Open
B1922 — Air Bag Safing Sensor Output Circuit Short To Battery
B1923 — Air Bag Memory Clear Circuit Short To Ground

The supplemental restraint system (SRS) — what most people call the airbag system — depends on constant self-diagnostics to stay ready. Code B1924 points to a fault within this monitoring loop: the internal diagnostic monitor has found a problem severe enough to disarm part of the system or report a self-check failure. When the SRS module runs its routines during each drive cycle, any reading that falls outside the expected range triggers this code after the fault is confirmed across multiple cycles.

The body control computer stores B1924 once the module decides the condition is genuine. Freeze frame data accompanies the code, recording engine speed, load, temperature, and vehicle speed at the exact moment the problem appeared — essential information for pinpointing whether this stems from a bad sensor, weak power supply, or damaged wiring.

Because the fault lives inside the restraint system, it often shows up alongside other SRS codes. The real concern: a system that has disarmed itself will not deploy its airbags during a crash.

Most drivers notice only one change when B1924 sets: the airbag warning lamp stays illuminated. The vehicle itself performs normally — no drivability symptoms, no loss of steering or braking. The danger is invisible until an accident occurs.

Common Symptoms of B1924

Airbag warning light remains on after startup
Dashboard displays an "airbag disabled" or "SRS fault" message
No drivability complaints — the car runs and handles normally
Code may appear alongside other SRS trouble codes
Symptoms sometimes disappear temporarily after clearing the code, only to return

What Causes B1924?

The most frequent culprit is damaged wiring or loose connectors under the front seats. Seat movement from regular adjustment or interior cleaning gradually loosens these connections, creating intermittent opens or shorts in the circuit. Beyond that, several other components commonly trigger this code:

Failed clockspring — the rotary connector in the steering column that carries power to the driver's airbag wears out from constant rotation
Faulty impact or occupancy sensor — these detect crash severity and feed data to the SRS module
SRS control module failure or residual crash data — a module that has stored a deployment event may lock itself in a fault state
Low system voltage or a depleted backup battery — the module needs stable power to run its self-diagnostics properly
Corrosion or poor contact at connectors in the steering column harness

How to Diagnose B1924

Start by connecting a scanner capable of reading SRS codes — standard OBD2 readers often cannot access airbag modules. Once you confirm B1924 is stored, save the freeze frame data before doing anything else. That snapshot tells you engine conditions when the fault first appeared.

Cross-reference any other trouble codes present. Related codes frequently point to the actual failing component rather than the symptom code. Also check manufacturer technical service bulletins for your specific make and model; many B0xxx-related issues have published factory fixes or software updates available through the dealer or NHTSA database.

Perform a hands-on inspection of the restraint system wiring. Focus on areas that move: under-seat harnesses, steering column connections, and any wiring near the driver's airbag. Look for chafed insulation, bent pins, moisture intrusion, or connectors that are not fully seated.

Use an SRS-specific scanner to interrogate the control module directly. This will reveal module-specific fault data, crash data retention, and sensor status that a generic scan tool cannot access.

Clear the code and complete a full drive cycle that recreates the conditions from the freeze frame — similar speed, load, and temperature. If B1924 returns, you have confirmed a genuine fault and can proceed with targeted repairs.

Repair Options for B1924

Address the cheapest and most common problems before committing to expensive replacements:

Reconnect or repair SRS wiring and connectors — $80–$250
Replace a faulty sensor or clockspring — $150–$500
Reset or replace the SRS control module — $300–$1,000

How Much Does Fixing B1924 Cost?

The final bill depends entirely on which part is at fault. At independent shop rates in the United States, typical scenarios break down as follows:

Wiring repairs or connector replacement: $80–$250
Clockspring or impact sensor replacement: $150–$500
SRS module reset (where applicable) or full replacement: $300–$1,000

Most B1924 repairs fall somewhere in the middle of that range, and a careful diagnosis before buying parts is the single most effective way to keep costs down. The module itself is rarely the first component to check.

Can You Drive with B1924?

The vehicle will continue to drive, brake, and steer without any noticeable difference. However, an active SRS fault means the airbag system has disabled itself — in a collision, the airbags may not deploy. This code warrants attention within days, not weeks. Drive it to a shop, but do not treat it as routine maintenance.