B1A78 on 2021-2024 Jeep Grand Wagoneer — Manufacturer-Specific Body/Security System Code
1 vehicles · 1 makes · $200-$1,800 repair
Most Reported On
B1A78 is an OBD-II diagnostic trouble code meaning “Manufacturer-Specific Body/Security System Code.” B1A78 is a manufacturer-specific body code in the security-systems range with no single standardized SAE definition. As with the other B1Axx codes, it generally relates to immobilizer, key/transponder, or security-module operation, but the exact meaning varies by automaker. The specific name and causes cannot be reliably stated without brand-specific documentation. Confirm with a make-appropriate scan tool. This code is most commonly reported on 2021-2024 Jeep Grand Wagoneer, with repair costs ranging from $200 to $1,800.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose B1A78, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
FAQ
What does B1A78 mean?
B1A78 stands for "Manufacturer-Specific Body/Security System Code." B1A78 is a manufacturer-specific body code in the security-systems range with no single standardized SAE definition. As with the other B1Axx codes, it generally relates to immobilizer, key/transponder, or security-module operation, but the exact meaning varies by automaker. The specific name and causes cannot be reliably stated without brand-specific documentation. Confirm with a make-appropriate scan tool.
What are the most common causes of B1A78?
The most common causes of B1A78 are: Immobilizer or anti-theft system fault, Key/transponder recognition problem, Security module communication error, Wiring or connector fault in the security circuit, Module configuration or software issue, Faulty body control / security module. The specific cause varies by vehicle.
How much does it cost to fix B1A78?
Repair costs for B1A78 range from $200 to $1,800, depending on the vehicle and root cause.
Which vehicles are affected by B1A78?
Au7o has documented B1A78 across 1 vehicle models from 1 manufacturers: Jeep.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.