B1905 — Air Bag Crash Sensor #2 Feed/Return Circuit Short To Battery

B1905 — Air Bag Crash Sensor #2 Feed/Return Circuit Short To Battery. A fault in the airbag / restraint system (SRS). Short, gentle driving to a shop is usually possible. Typical causes: SRS control module fault or stored crash data, damaged wiring under seats or in the steering column, faulty impact or occupancy sensor.

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 B1905 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 B1905 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1905 (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 B1905 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

How do I diagnose B1905 myself?

Start with a scan: confirm B1905, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the airbag / restraint system (SRS), and verify the suspect component against live data before buying parts.

Will B1905 clear itself?

Sometimes B1905 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.

Is it safe to drive with B1905?

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 is the most common cause of B1905?

The most common causes are: SRS control module fault or stored crash data, damaged wiring under seats or in the steering column, faulty impact or occupancy sensor.

What are the symptoms of B1905?

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

When your scanner pulls B1905, the vehicle's supplemental restraint system (SRS) has detected abnormal voltage on a specific circuit tied to crash sensor number two. Code B1905 translates to "Air Bag Crash Sensor #2 Feed/Return Circuit Short To Battery," meaning the sensor is seeing battery voltage where it should not be present during normal operation. This fault falls under the body electrical category and indicates the sensing circuit has experienced a short to constant power, which can prevent proper crash detection and airbag deployment.

The SRS control module continuously monitors the crash sensors, airbags, and related wiring throughout normal driving. When B1905 sets, the module has compared live sensor data against factory-calibrated parameters across multiple drive cycles and found a discrepancy. The system stores a freeze frame snapshot capturing engine RPM, load, coolant temperature, and vehicle speed at the exact moment the fault was detected. That snapshot is invaluable during diagnosis because it reveals the driving conditions present when the short occurred, helping technicians reproduce the failure and verify the fix.

Airbag systems are designed with redundant safety measures. When the control module detects a fault like B1905, it typically disables the entire SRS to prevent an accidental deployment. This protective shutdown explains why you may see a disabled message alongside the warning light.

Symptoms of B1905

"Airbag system disabled" message displayed in the instrument cluster
Supplemental Restraint System (SRS) or airbag warning light illuminated
No drivability issues present — the vehicle steers, brakes, and accelerates normally
Occasionally, intermittent warning light behavior depending on whether the short is permanent or condition-based
Possible stored diagnostic history in the module showing multiple B1905 occurrences

Common Causes

The most frequent culprit behind B1905 is a faulty SRS control module, which may contain corrupted calibration data or have recorded crash deployment information that was never cleared. Impact or occupancy sensors in the door sills, seats, or front crush zones commonly fail and produce this exact circuit condition. A failed clockspring — the rotating electrical connector inside the steering column that carries signals to the driver airbag — occasionally causes feed/return circuit shorts that trigger B1905. Low system voltage or a depleted backup battery can also create false fault conditions by preventing proper module communication. Finally, damaged, chafed, or corroded wiring under the seats or within the steering column often creates direct shorts to battery power on the sensor circuits.

Diagnostic Steps

Connect an OBD2 scanner capable of reading SRS codes, confirm B1905 is stored, and record all freeze frame data before clearing anything. This information guides the entire repair process.
Pull all stored and pending codes from every module. Related codes in the same circuit often point directly to the failed component rather than requiring guesswork. Check manufacturer technical service bulletins for your specific make and model, as some B1905 failures have documented factory fixes or software recalibrations.
Perform a thorough visual inspection of the wiring harness and connectors associated with the second crash sensor. Look for damaged insulation, broken wires, corrosion buildup, and loose or pushed-out pins, particularly at connectors under the front seats and behind the steering column trim.
Use a scanner or diagnostic tool that specifically supports airbag module communication. Standard generic OBD2 scanners cannot access SRS data on most vehicles, leaving the module unreadable.
Examine all under-seat connectors and wiring. These connections experience constant flexing from seat adjustment and are frequently disturbed during interior cleaning, making them prime candidates for intermittent shorts.
After clearing the code, perform a complete drive cycle that recreates the conditions captured in the freeze frame data. Watch for the warning light to return, which confirms the fault is still present and active rather than a one-time electrical spike.

Repair Options and Costs

SRS module reset or replacement: $300–$1,000

The module may require specialist recalibration to clear stored crash data, or full replacement if internal circuitry has failed. This represents the highest individual line-item cost.

Sensor or clockspring replacement: $150–$500

Impact sensors, occupancy classification sensors, or the steering column clockspring can each produce the B1905 circuit condition. Parts and labor vary based on vehicle architecture and component accessibility.

Wiring and connector repair: $80–$250

Repairing damaged wiring, replacing connectors, or reseating loose harness connections typically costs the least while resolving many B1905 cases caused by chafed insulation or poor contact.

Total Cost to Fix B1905

Depending on which component is actually responsible for the short, total repair costs typically fall between $80 and $1,000. The most economical path involves methodical diagnosis before purchasing any parts, since the least expensive repair option is rarely the one most people try first. Skipping proper verification often leads to replacing expensive modules when the actual problem was simply a loose connector or damaged wire.

Can You Drive with B1905?

The vehicle operates and drives without any noticeable difference in handling or performance. However, the SRS warning light signals that the airbag system has been disabled, meaning the airbags will not inflate during a collision. This transforms B1905 from a minor inconvenience into a safety-critical concern. Driving to a repair facility is acceptable, but leaving this code unresolved for weeks or months is not advisable, particularly if you rely on the vehicle for daily transportation.