B2603 on Nissan
Body/Control Circuit Fault (manufacturer-specific)
B2603 on Nissan vehicles indicates body/control circuit fault (manufacturer-specific). Au7o has documented this code across 1 Nissan model — most commonly on Sentra. 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. Typical repair costs on Nissan range from $180 to $700, depending on the specific model and root cause.
Common Causes of B2603
- •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
B2603 on Nissan by Model
Nissan Sentra(1 issue)
- Intermittent No-Start or Engine Stall Linked to Stop/Start and 12V Battery Weakness2023-2025
A recurring owner complaint on newer Sentras involves weak factory batteries, hard starting, no-start conditions, or stalling/rough restart behavior associated with the idle stop/start system. The problem often appears early in ownership and may be aggravated by short-trip driving or battery state-of-charge issues. In some cases, owners report multiple jump-starts or battery replacement within the first few years.
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View B2603 across all makes →Frequently Asked Questions
What does B2603 mean on Nissan?▼
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. On Nissan specifically, this code is documented across 1 model.
What causes B2603 on Nissan vehicles?▼
Common causes on Nissan: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix B2603 on a Nissan?▼
Repair costs on Nissan range from $180 to $700, depending on the specific model and root cause.
Which Nissan models have B2603 documented?▼
Au7o has documented B2603 on 1 Nissan model: Sentra.