OBD-II Fault Code

P1305: EGR Calibration Low

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P1305.

System family

Powertrain

Manufacturer-specific

Repair category

EGR / emissions

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 P1305 usually means

EGR Calibration Low.

Common symptoms

Check Engine light; Poor drivability or reduced fuel economy depending on fault

Likely causes

Stuck EGR valve; Blocked EGR passage; Vacuum/control solenoid fault; DPFE/position sensor fault; Low signal voltage; Weak power supply; High resistance/poor ground; Failed sensor

Diagnostic checks

Scan all modules and record freeze-frame data before clearing codes; Check battery voltage and related fuses; Command EGR operation if supported; Inspect passages for carbon blockage; Check sensor reference voltage, ground and signal voltage

Repair guidance

Clean carbon passages, repair vacuum/control circuit, replace stuck valve or failed sensor after testing; Repair poor ground/power feed or replace confirmed faulty sensor

Verification after repair

Clear code, road-test through the same drive condition, then 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.