If your turbo-equipped vehicle has triggered the P0246 diagnostic trouble code, it means the engine control module (ECM) has detected an abnormally high voltage signal in the turbocharger wastegate solenoid circuit. This is a moderate severity code that affects your vehicle’s air/fuel metering system and can impact engine performance, boost control, and fuel efficiency. Understanding what’s causing this code is essential to getting your vehicle back to normal operation.
What Does P0246 Mean?
The P0246 code specifically refers to a “Turbo/Supercharger Wastegate Solenoid Circuit High” condition. Here’s the technical breakdown:
- P: Powertrain code (engine, transmission, drivetrain)
- 0: Generic OBD-II code (standardized across manufacturers)
- 2: Air/Fuel Metering system
- 46: Turbo/Supercharger Wastegate Solenoid Circuit High
The wastegate solenoid is an electromagnetic valve that controls boost pressure in turbocharged engines. When the ECM detects a voltage reading higher than the expected range (typically above 4.5V in a 5V system), it sets this code. This can indicate an electrical short, a faulty solenoid, wiring damage, or a problem with the ECM’s control circuit.
Common Symptoms
- Check Engine Light illuminated on the dashboard
- Reduced engine boost pressure or loss of turbo power
- Poor acceleration or sluggish throttle response
- Decreased fuel economy
- Rough idle or engine hesitation
- Possible overboost condition (excessive turbo pressure)
- Hissing or whistling sounds from the turbo area
- Engine may enter limp mode to protect itself
Possible Causes
Listed from most to least common:
- Faulty Wastegate Solenoid (Most Common) – The solenoid coil has failed internally, causing abnormal resistance or a short circuit that produces high voltage readings.
- Damaged or Shorted Wiring – Wires in the solenoid circuit are corroded, pinched, or have insulation damage causing a short to power.
- Poor Electrical Connections – Loose, corroded, or disconnected connectors at the solenoid or ECM causing intermittent high voltage signals.
- ECM Control Circuit Malfunction – The engine control module’s output driver for the wastegate solenoid is failing, unable to properly regulate voltage.
- Voltage Regulator Failure – A faulty voltage regulator supplying the solenoid circuit is delivering excessive voltage.
- Ground Connection Issues – Poor or missing ground connections in the solenoid circuit preventing proper voltage regulation.
- Turbo Boost Sensor Malfunction – A faulty boost pressure sensor sending incorrect readings, causing the ECM to misinterpret solenoid performance.
Diagnostic Steps
Follow these steps to diagnose the P0246 code:
Step 1: Scan for Additional Codes
Use an OBD-II scanner to check for other related codes (P0245, P0247, P0248, or boost-related codes). Multiple codes can indicate a broader system issue.
Step 2: Visual Inspection
Inspect the wastegate solenoid and its wiring harness:
- Look for visible corrosion, cracks, or damage on the solenoid connector
- Check for pinched, melted, or frayed wires near the solenoid
- Ensure the connector is fully seated and not loose
- Inspect ground connections for corrosion or looseness
Step 3: Electrical Testing
With the engine off and key in the ON position:
- Use a multimeter to measure voltage at the solenoid connector – should be 0V or battery voltage depending on solenoid design
- Measure resistance across the solenoid coil – typical range is 4-8 ohms (consult your vehicle’s service manual for exact specs)
- Check for continuity in the wiring harness
- Test ground connections for proper continuity
Step 4: Connector and Wiring Repair
If connections are corroded or loose:
- Disconnect the solenoid connector
- Clean terminals with electrical contact cleaner
- Reconnect firmly and retest with the scanner
- Repair or replace any damaged wiring
Step 5: Solenoid Replacement
If electrical testing shows the solenoid resistance is out of spec or infinite (open circuit):
- Locate the wastegate solenoid (typically mounted on or near the turbo)
- Disconnect the electrical connector and vacuum hoses
- Remove the mounting bolts
- Install the new solenoid and reconnect all hoses and connectors
- Clear the code and test drive
Step 6: ECM Testing
If the solenoid and wiring are good, the ECM control circuit may be faulty. This requires advanced diagnostics and may need professional service.
Repair Cost Estimates
Typical repair costs for P0246 vary based on the root cause:
- Connector Cleaning/Repair: $50–$150 (DIY possible, or quick shop visit)
- Wiring Repair/Replacement: $100–$400 (depends on extent of damage)
- Wastegate Solenoid Replacement: $200–$600 (parts + labor; solenoid typically $100–$300, labor 1–2 hours)
- ECM Repair/Replacement: $800–$2,500+ (rare; requires specialized diagnostics)
Note: Costs vary by vehicle make/model, location, and whether you use OEM or aftermarket parts. Always get a diagnostic quote before authorizing repairs.
Can I Still Drive?
Severity: Moderate
Yes, you can typically drive with P0246 active, but with caution:
- Short trips are generally safe – The code alone won’t cause immediate engine damage.
- Avoid aggressive driving – Reduced boost control can stress the engine if you demand high power.
- Monitor performance – If the engine enters limp mode or you notice severe power loss, stop driving and seek service.
- Get it diagnosed soon – While not critical, a faulty wastegate solenoid can lead to overboost conditions that damage the turbo if left unaddressed.
- Fuel economy will suffer – Expect reduced MPG until the issue is fixed.
If you experience overboost (excessive turbo pressure), loss of all boost, or engine knocking, stop driving immediately and have the vehicle towed to a repair facility.
Frequently Asked Questions
Q: What’s the difference between P0246 and P0245?
A: P0245 indicates a “Turbo Wastegate Solenoid Circuit Low” (low voltage), while P0246 is “Circuit High” (high voltage). P0245 typically suggests an open circuit or insufficient voltage, while P0246 indicates a short or excessive voltage. Both require similar diagnostic steps but may point to different failure modes.
Q: Can a bad boost sensor cause P0246?
A: Indirectly, yes. If the boost pressure sensor is faulty, it sends incorrect readings to the ECM, which may misinterpret the solenoid’s performance and set P0246. However, the code specifically points to the solenoid circuit itself, so always test the solenoid first before replacing the sensor.
Q: Will clearing the code fix the problem?
A: No. Clearing the code with a scanner will temporarily remove the Check Engine Light, but the underlying problem remains. The code will return after a few drive cycles. You must diagnose and repair the root cause (solenoid, wiring, or connections) for a permanent fix.
Q: Is the wastegate solenoid expensive to replace?
A: The solenoid itself typically costs $100–$300 depending on your vehicle. Labor usually runs 1–2 hours ($100–$300), bringing total repair cost to $200–$600. Some vehicles have easier access than others, so location matters. Always get a quote from your mechanic for your specific vehicle.