P0249 Turbocharger Wastegate Solenoid B Low
OBD-II Trouble Code Technical Description
Turbocharger Wastegate Solenoid B Low
What does that mean?
This generic powertrain/engine diagnostic trouble code typically applies to turbocharged and supercharged engines, including but not limited to certain Audi, Ford, GM, Mercedes, Mitsubishi, VW and Volvo vehicles.
The Powertrain Control Module (PCM) controls the boost pressure in a gasoline or diesel engine by controlling the output circuit to the "B" wastegate/boost pressure control solenoid.
Depending upon how the manufacturer activates the solenoid, when the PCM provides a power supply or a ground to the solenoid to energize it and the PCM notices that there is no voltage at any time to the circuit when there should be (de-energized), the PCM will set code P0249. This code is considered to be an electrical circuit fault only.
Troubleshooting steps may vary depending upon manufacturer, type of wastegate/boost pressure control, and wire colors to the control solenoid.
Symptoms
Symptoms of a P0249 engine code may include:
Malfunction Indicator Light On Instrument cluster message alerting driver to condition Lack of powerCauses
Potential causes for this code to set are:
Open in the control circuit (ground circuit) between the wastegate/boost pressure control solenoid B and the PCM Open in the power supply circuit between the wastegate/boost pressure control solenoid B and the PCM Short to ground in the power supply circuit to the wastegate/boost pressure control solenoid B Wastegate/boost pressure control solenoid B faulty Possibly a PCM has failed (highly unlikely)Diagnostic and Repair Procedures
A good starting point is always to check for technical service bulletins (TSB) for your particular vehicle. Your issue may be a known issue with a known fix put out by the manufacturer and can save you time and money during diagnosis.
Next, locate the "B" wastegate/boost pressure control solenoid on your particular vehicle. Once located, visually inspect the connectors and wiring. Look for scraping, rubbing, bare wires, burn spots or melted plastic. Pull the connectors apart and carefully inspect the terminals (the metal parts) inside the connectors. See if they look burned or have a green tint indicating corrosion. Use electrical contact cleaner and a plastic bristle brush if cleaning of the terminals is needed. Let dry and apply electrical grease where the terminals contact.
The most common failure is due to connection issues.
If you have a scan tool, clear the diagnostic trouble codes from memory, and see if P0249 returns. If it does not, then the connections were most likely your problem.
If the code does return, we will need to test the solenoid and its associated circuits. Typically, there are 2 wires at the wastegate/boost pressure control solenoid. First, disconnect the harness going to the wastegate/boost pressure control solenoid. With a Digital Volt Ohm Meter (DVOM), connect one lead of the meter to one terminal of the solenoid. Connect the remaining meter lead to the other solenoid terminal. It should not be open or shorted. Verify the resistance specifications for your particular vehicle. If the solenoid is either open or shorted (infinite resistance or no resistance/0 ohms), replace the solenoid.
If that test passes, with a DVOM, check to make sure you have 12V on the wastegate/boost pressure control solenoid power supply circuit (Red lead to the solenoid power supply circuit, black lead to a good ground). Insure ignition is on. If there is no 12 volts to the solenoid, or if there is 12 volts when the ignition is turned off, repair the wiring from the PCM or relay to the solenoid, or possibly a bad PCM.
If that’s OK, check to make sure you have a good ground at the wastegate/boost pr
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