B2778 Code - Passenger Side Curtain Air Bag Module Circuit Resistance High
Quick Answer
The Sophisticated Air Bag Sensor (SAS) Control Module monitors the Passenger Side Curtain Air Bag Module. Common causes include Faulty Passenger Side Curtain Air Bag Module, Passenger Side Curtain Air Bag Module harness is open or shorted, Passenger Side Curtain Air Bag Module 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
- B2778 indicates Passenger Side Curtain Air Bag Module Circuit Resistance High.
- Common causes
- Common causes include Faulty Passenger Side Curtain Air Bag Module, Passenger Side Curtain Air Bag Module harness is open or shorted, Passenger Side Curtain Air Bag Module 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 B2778 Description
What are the Possible Causes of the DTC B2778?
- Faulty Passenger Side Curtain Air Bag Module
- Passenger Side Curtain Air Bag Module harness is open or shorted
- Passenger Side Curtain Air Bag Module circuit poor electrical connection
- Faulty Sophisticated Air Bag Sensor (SAS)
How to Fix the DTC B2778?
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 B2778 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.
Need more information about the B2778 code?
Need more information on how to fix the B2778 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the B2778 code diagnosed by a professional: Find a repair shop in your area
Information for Specific Makes
- B2778 Mazda — Passenger Side Curtain Air Bag Module Circuit Resistance High
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 B2778 Code
1. What does the OBDII code B2778 mean?
B2778 indicates that the resistance in the passenger side curtain airbag module circuit is too high, which may interfere with proper airbag deployment.
2. What are the common symptoms of code B2778?
Symptoms include an illuminated airbag warning light, the passenger airbag system being disabled, and a potential warning chime on some vehicles.
3. What causes code B2778 to appear?
Common causes include damaged or corroded wiring, loose or poor electrical connections, a faulty side curtain airbag module, or a malfunctioning airbag control module.
4. Can I still drive my car with code B2778?
While the car may still be drivable, the passenger side curtain airbag may not deploy in an accident, posing a safety risk. It’s best to address the issue promptly.
5. How can I diagnose the B2778 code?
Diagnosis typically involves checking the airbag system wiring and connectors for damage, inspecting for corrosion, and testing the resistance of the airbag module circuit with a multimeter.
6. What are possible repair solutions for code B2778?
Repairs may include replacing damaged wiring, cleaning corroded connections, tightening loose connectors, or replacing a faulty passenger side curtain airbag module.
7. How much does it cost to fix code B2778?
Repair costs vary, but fixing wiring or connectors may cost $50-$200, while replacing an airbag module could cost $500-$1,500 depending on the vehicle.
8. Can I clear the B2778 code without fixing the issue?
Clearing the code without addressing the root cause is not recommended, as the airbag system may remain disabled, posing a safety hazard.
9. Is code B2778 specific to certain vehicles?
No, code B2778 can occur in any vehicle equipped with OBDII systems and side curtain airbags, though the exact repair process may vary by make and model.
10. Can a dead battery cause code B2778?
A dead or weak battery is unlikely to cause this specific code, but voltage fluctuations during a low-battery condition might exacerbate existing circuit issues.
Discuss the causes and fixes for B2778 OBDII Code
Code B2778 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
