P0249
Turbo/Supercharger Wastegate Solenoid B Low
When a vehicle powertrain module registers the fault code P0249, it points directly to an internal system malfunction identified as "Turbo/Supercharger Wastegate Solenoid B Low". Operating your engine under this condition may degrade long-term fuel maps.
Driver's Summary
Code P0249 means your vehicle detected a problem with the turbo/supercharger wastegate solenoid b low system. On the road, this usually shows up as constant underboost, limp mode. This is not a code to ignore — the underlying fault can rapidly worsen and lead to costly repairs if driving continues.
Symptoms
Constant underboost, limp mode
Common Causes
- Short to ground in solenoid B circuit
- Failed solenoid B
- Wiring harness short
- Failed PCM
How to Fix
- 1 Repair short to ground
- 2 Replace wastegate solenoid B
- 3 Repair wiring harness
- 4 Replace PCM
Technical Explanation
The PCM triggers P0249 after its internal monitoring routine detects that a specific circuit or sensor has exceeded its acceptable operating range. The PCM monitors crankshaft rotational velocity via the CKP sensor at a resolution of individual tooth gaps on the reluctor ring. A combustion event in each cylinder produces a measurable acceleration spike; its absence or weakness is flagged as a misfire event within a 200-revolution or 1000-revolution test window. After two failed drive cycles, the code transitions from a pending to a confirmed DTC, and the PCM activates the MIL. Clearing the code without repairing the fault will result in re-illumination within one to two complete drive cycles.
Is It Safe to Drive?
This fault carries real mechanical risk. The root causes — including short to ground in solenoid b circuit — can trigger a chain reaction of component failures if the vehicle continues to be driven. Have it towed or drive directly to a shop without delay.
Mechanic's Pro Tip
Before replacing any component on P0249, spend 5 minutes inspecting the wiring harness and connector first — corrosion, chafed insulation, and backed-out pins cause the majority of these faults and cost nothing to fix. Use a multimeter to measure voltage drop across the connector pins under load; anything above 0.1V indicates excessive resistance that will cause intermittent failures even after replacing the sensor.
Related Fault Codes
Frequently Asked Questions
What does OBD2 code P0249 mean?
OBD2 code P0249 refers to Turbo/Supercharger Wastegate Solenoid B Low. When a vehicle powertrain module registers the fault code P0249, it points directly to an internal system malfunction identified as "Turbo/Supercharger Wastegate Solenoid B Low". Operating your engine under this condition may degrade long-term fuel maps.
What are the most common symptoms of DTC P0249?
Drivers experiencing code P0249 typically report: Constant underboost, limp mode.
Is it safe to drive with trouble code P0249 active?
This fault carries real mechanical risk. The root causes — including short to ground in solenoid b circuit — can trigger a chain reaction of component failures if the vehicle continues to be driven. Have it towed or drive directly to a shop without delay.
How much does it cost to fix code P0249?
The estimated repair cost for P0249 ranges from $80 to $350 USD. Solenoid: 80 - 200
Solenoid: 80 - 200
Need Professional Diagnostic Assistance?
Always verify sensor signals and wiring integrity with an OBD2 scanner before purchasing replacement parts.
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