B1A78 on Jeep: How to Diagnose & Fix
Manufacturer-Specific Body/Security System Code
1 Jeep model · 1 documented issue · $200-$1,800 repair
B1A78 on Jeep by model: symptoms, diagnosis and fix
The second-row captain's chairs equipped with power adjustment and memory functions on Grand Wagoneer L and standard models have been reported to fail to return to memorized positions or become entirely non-operational. The seat position memory module loses stored settings after a battery event, and the seat track actuator motors can bind in the rearmost position, blocking third-row access. Owner complaints on forums and NHTSA describe seats that move to a position and stop mid-travel, or refuse to respond to the Easy Entry function.
Common Symptoms
- Second-row seat stops mid-travel during adjustment
- Memory seat position lost after battery disconnect or replacement
- Easy Entry function fails to slide seat forward for third-row access
- Seat buttons unresponsive or require multiple presses
- Error message on cluster related to seat system
How to Fix
Reprogram seat memory module via dealer J2534 tool with latest software update. If motor binding is present, the seat track assembly requires lubrication with Mopar seat track lubricant or replacement of the seat track motor assembly. In some cases, replacing the seat control module (SCM) resolves the memory loss issue permanently.
B1A78 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does B1A78 mean on a Jeep?
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. On Jeep it is documented across 1 model: Grand Wagoneer.
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 on a Jeep?
Published repair estimates on Jeep range from $200 to $1,800 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for B1A78 on a different make?
View B1A78 across all makes →Join 700+ subscribers following Au7o for vehicle insights and updates.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.