OBD-II Fault Code

B1203: Fuel Sender Circuit Short To Battery

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for B1203.

System family

Body

Manufacturer-specific

Repair category

Fuel system

Use this category to narrow your checks before replacing parts.

Severity

Medium

Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.

What B1203 usually means

Fuel Sender Circuit Short To Battery.

Common symptoms

Body/accessory warning lamp or feature not working; Hard start, hesitation, stalling or inaccurate fuel reading depending on component

Likely causes

Low fuel pressure; Faulty pump/regulator/sensor; Wiring fault; Clogged filter; Injector fault; Wire shorted to power feed; Incorrectly repaired harness; Internal component short

Diagnostic checks

Check related fuses, connectors, grounds and switch/module power supply; Check fuel pressure and sensor data; Inspect pump/injector fuses, relay, wiring and grounds; Check for unwanted voltage on signal/control circuit

Repair guidance

Repair wiring/relay issues, replace clogged filter, failed pump/sensor/injector only after testing; Repair harness short to power or replace internally shorted component

Verification after repair

Operate the affected body/accessory system and rescan

Note: Confirm vehicle make/model/year because manufacturer-specific codes can vary; Manufacturer-specific: confirm definition and test steps in the vehicle service manual. A DTC identifies a circuit or system condition, not always the failed part.