B2603 on 2023-2025 Nissan Sentra — Body/Control Circuit Fault (manufacturer-specific)
1 vehicles · 1 makes · $180-$700 repair
Most Reported On
B2603 is an OBD-II diagnostic trouble code meaning “Body/Control Circuit Fault (manufacturer-specific).” B2603 is a manufacturer-specific body code whose meaning differs by automaker. On many GM vehicles it is defined as the daytime running lamp (DRL) relay control circuit shorted to battery voltage, while on Nissan it relates to the shift-position status input monitored by the body/security control module. Because the definition varies, it should be confirmed against the specific make's service information before diagnosis. This code is most commonly reported on 2023-2025 Nissan Sentra, with repair costs ranging from $180 to $700.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose B2603, 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
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FAQ
What does B2603 mean?
B2603 stands for "Body/Control Circuit Fault (manufacturer-specific)." B2603 is a manufacturer-specific body code whose meaning differs by automaker. On many GM vehicles it is defined as the daytime running lamp (DRL) relay control circuit shorted to battery voltage, while on Nissan it relates to the shift-position status input monitored by the body/security control module. Because the definition varies, it should be confirmed against the specific make's service information before diagnosis.
What are the most common causes of B2603?
The most common causes of B2603 are: Shorted DRL relay control circuit (GM), Faulty DRL relay or lighting control module (GM), Shift/park position switch or input fault (Nissan), Damaged wiring shorted to power or ground, Corroded connectors in the affected circuit, Body/security control module fault. The specific cause varies by vehicle.
How much does it cost to fix B2603?
Repair costs for B2603 range from $180 to $700, depending on the vehicle and root cause.
Which vehicles are affected by B2603?
Au7o has documented B2603 across 1 vehicle models from 1 manufacturers: Nissan.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.