Powertrain
Generic/SAE
OBD-II Fault Code
P0249: Turbocharger Wastegate Solenoid B Low
Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0249.
Transmission / driveline
Use this category to narrow your checks before replacing parts.
High
Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.
What P0249 usually means
Turbocharger Wastegate Solenoid B Low.
Common symptoms
Check Engine light; Poor drivability or reduced fuel economy depending on fault; Harsh shifting, limp mode, slipping or delayed engagement possible
Likely causes
Low/dirty transmission fluid; Solenoid/valve body issue; Wiring fault; Internal transmission wear; 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; Check transmission fluid level/condition using correct procedure; Scan TCM data and inspect connector/wiring; Check sensor reference voltage, ground and signal voltage
Repair guidance
Service/repair fluid or wiring issues first, test solenoid/valve body, seek transmission specialist for internal faults; Repair poor ground/power feed or replace confirmed faulty sensor
Verification after repair
Clear code, road-test through the same drive condition, then rescan