P0242
Fix within a few daysThe engine computer detected a low voltage in the control circuit for the turbocharger or supercharger wastegate solenoid 'B'. This means the wastegate isn't being controlled correctly.
Code P0242 means the engine computer detected a low voltage in the wastegate solenoid 'B' circuit. Common causes: Faulty wastegate solenoid (70%), wiring issues (25%). Drivability: Yes, but with reduced power. Repair cost: $100-$300 DIY, $200-$600 professional.
Can I Drive With P0242?
Yes, for short trips only
Essential trips under 10 miles, avoid highways and heavy acceleration. Expect significantly reduced power.
Stop driving immediately if: Loud noises from the engine or turbo, burning smell, or a flashing Check Engine Light (indicating a severe misfire or engine damage).
Symptoms of P0242
- 1Check Engine Light is on
- 2Reduced engine power or 'limp mode'
- 3Poor acceleration
- 4Engine feels sluggish
Common Causes of P0242
Parts most likely causing this code, ranked by probability
An internal electrical fault or mechanical failure within the solenoid prevents it from receiving or responding to the correct voltage signal.
70% of P0242 cases are fixed by replacing this part
Damaged, corroded, or loose wiring or a faulty connector to the wastegate solenoid 'B' causes a low voltage condition in the circuit.
25% of P0242 cases are fixed by repairing wiring or connectors
A rare internal fault within the engine computer prevents it from sending the correct voltage signal to the wastegate solenoid 'B'.
5% of P0242 cases are fixed by replacing the ECM/PCM
Check These First (Before Buying Parts)
- Visually inspect the wastegate solenoid 'B' and its electrical connector and wiring for any obvious damage, corrosion, or loose connections. Make sure the connector is fully seated.
How to Diagnose P0242
- 1Visually inspect the wastegate solenoid 'B' and its electrical connector and wiring for any signs of damage, corrosion, or loose connections.
- 2Using a multimeter, check for proper voltage supply at the wastegate solenoid 'B' connector with the ignition on.
- 3Measure the resistance of the wastegate solenoid 'B' across its terminals. Compare to manufacturer specifications.
- 4If possible, use a scan tool to command the wastegate solenoid 'B' on and off to check for proper operation and listen for a click.
- 5If the solenoid and wiring test good, consider further diagnosis of the Engine Control Module (ECM/PCM).
P0242 on Popular Vehicles
Ford F-150
2011-2024Common on EcoBoost engines. The wastegate solenoid 'B' can fail due to heat or internal electrical issues, leading to P0242 and reduced power.
75% fixed by replacing the wastegate solenoid 'B'
Chevrolet Silverado
2019-2024For models with turbocharged engines, P0242 can occur due to a faulty wastegate solenoid 'B' or wiring issues related to boost control.
65% fixed by replacing the wastegate solenoid 'B'
Subaru WRX/STI
2002-2021While other boost codes are more common, P0242 can appear if the wastegate solenoid (often called boost control solenoid) or its wiring has an electrical fault.
60% fixed by replacing the wastegate solenoid 'B'
Frequently Asked Questions
What does P0242 mean?
P0242 indicates that the engine's computer has detected a low voltage condition in the control circuit for the turbocharger or supercharger wastegate solenoid 'B'. This solenoid is crucial for regulating boost pressure.
Can I drive with P0242?
Yes, you can drive with P0242, but your vehicle will have reduced power and acceleration. The engine will likely be in 'limp mode' to protect itself. Fix this within a few days to restore full performance and prevent potential long-term issues.
Will P0242 clear itself?
No, P0242 will not clear itself. The underlying electrical or mechanical fault needs to be repaired. Once the repair is made, you will need to clear the code with an OBD-II scanner.
How do I fix P0242 myself?
Start by inspecting the wiring and connector to the wastegate solenoid 'B' for damage. If the wiring is good, test the solenoid's resistance and voltage at its connector using a multimeter. If the solenoid tests faulty, replacing it is the most common fix.
How much does it cost to fix P0242?
DIY repair costs for P0242 typically range from $50 to $200 for a new wastegate solenoid. Professional repair at a shop will cost between $200 and $600, including parts and labor.
P0242 keeps coming back - why?
If P0242 keeps returning, it indicates the initial repair did not address the root cause. This often points to a persistent wiring issue, a faulty connector that wasn't fully repaired, or a rare problem with the Engine Control Module (ECM/PCM) itself.
Will P0242 fail emissions/smog test?
Yes, P0242 will cause your vehicle to fail an emissions or smog test. A Check Engine Light (CEL) illuminated for any reason is an automatic failure in states with such inspections.
What's the difference between P0242 and P0240?
P0242 specifically indicates a low voltage condition in the wastegate solenoid 'B' control circuit, pointing to an electrical issue. P0240, on the other hand, indicates a 'Turbocharger/Supercharger Boost Sensor 'A' Circuit Range/Performance' problem, suggesting the boost pressure itself is out of expected range, which could be mechanical or sensor-related.
P0242 on Ford F-150?
P0242 is a common code on Ford F-150 models equipped with EcoBoost engines. The wastegate solenoid 'B' (often located near the turbocharger) can fail due to heat exposure or internal electrical issues, leading to reduced boost and power.
Questions to Ask Your Mechanic
Did you check the voltage at the wastegate solenoid 'B' connector?
Good answer: Yes, I confirmed the correct voltage is reaching the solenoid, which tells me the wiring from the PCM is good.
What was the resistance reading of the wastegate solenoid 'B'?
Good answer: The solenoid showed an open circuit (or resistance outside specification), indicating an internal failure.
Did you inspect the wiring harness for any chafing or corrosion?
Good answer: Yes, I thoroughly checked the harness from the PCM to the solenoid and found no visible damage or corrosion.
Repair Cost Estimate
DIY Repair
Parts only
$50-$200
Shop Repair
Parts + labor
$200-$600
Save $150-$400 by doing it yourself
Difficulty
intermediate
Time
1-2 hours
Intermediate. Requires basic electrical testing skills with a multimeter and familiarity with engine bay components.
Cost of Waiting
Ignoring P0242 means your engine will continue to operate with reduced power and potentially higher fuel consumption. Prolonged incorrect boost pressure can put undue stress on the turbocharger, leading to premature wear or failure, which is a much more expensive repair ($1,000-$3,000+).
While You're In There...
This sensor works closely with the wastegate solenoid to regulate boost. If you're already diagnosing boost issues, checking or replacing this sensor can prevent future related codes.
Some wastegate solenoids use vacuum to operate. Inspecting and replacing any cracked or brittle vacuum lines while you have access can prevent boost control issues.
Tools You'll Need
- OBD-II Scan Tool
- Multimeter
- Basic Hand Tools (sockets, wrenches)
- Wire strippers/crimpers (if wiring repair is needed)
P0242 is a common code for turbocharged or supercharged engines. The fix is usually a straightforward solenoid replacement, restoring full power and efficiency to your engine.
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Your Next Steps
Step 1: Perform a thorough visual inspection of the wastegate solenoid 'B' and its wiring harness and connector. Look for any signs of damage, fraying, corrosion, or loose connections. Ensure the connector is securely attached.
Step 2: If the visual inspection doesn't reveal any issues, use a multimeter to test the resistance of the wastegate solenoid 'B' and check for proper voltage at its connector. Compare your readings to the vehicle's service manual specifications.
Step 3: If the solenoid tests faulty, replace it. If the wiring is damaged, repair it. If both test good, further diagnosis of the Engine Control Module (ECM/PCM) may be necessary, but this is rare. Parts you'll likely need: a new wastegate solenoid 'B'.