The OBD2 code P0081 points to an issue with the “Intake Valve Control Solenoid Circuit B2,” meaning the system that controls how air enters the engine isn’t working right on one side. This can cause your car to feel sluggish when you try to speed up and to use more gas than usual.
P0081 quick overview
| Meaning | P0081: Intake Valve Control Solenoid Circuit B2 |
| Is it serious? | Yes, it can affect your car’s performance and gas mileage. |
| Possible causes | – Corroded or poor wire harness connections – Faulty control solenoid – Short to power in the wire harness – Potential PCM issues |
| How to diagnose? | Check all wire connections for corrosion or damage. Test the wire harness for resistance issues. Watch the solenoid in action to see how it’s working while you drive. Look for shorts that could send too much power to the circuit. |
P0081 Meaning
If your car’s showing a P0081 code, it’s having trouble with the part that controls the air coming into the engine, specifically on one side. This might make your car not pick up speed well or use more fuel. The trouble could be from wires that got damaged or a part that’s not working right.
Mechanics usually start by checking the wires for any signs of damage or rust and then make sure the solenoid—the part that opens and closes to let air in—is doing its job right. Sometimes, they might even find the car’s computer (PCM) is the root of the problem.
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
How to fix P0081 – learn from mechanics
I looked into P0081 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Toyota P0081
Vehicle information
2014 Toyota Tundra Limited 5.7L V8
Issue + repair history
- Check engine light on with code P0081
- Poor acceleration and decreased fuel economy reported by the driver
- Inspected wire harness connections and control solenoid
- Found corroded terminals in the wire harness
- Cleaned and repaired wire harness connections
- Cleared codes, but issue persisted
Other OBD2 Codes + Test Results
- P0081: Intake Valve Control Solenoid Circuit B2
- No additional OBD2 codes mentioned
Mechanic suggestions
- Recheck wire harness connections for any further corrosion or poor connections
- Test resistance in the wire harness and connections
- Monitor solenoid during engine operation to assess duty cycle
Final fix
Discovered corroded terminals in the wire harness. Cleaned and repaired wire harness connections. Cleared codes, and issue resolved. Vehicle returned to normal operation.
Case #2: Honda P0081
Vehicle information
2016 Honda Pilot Touring 3.5L V6
Issue + repair history
- Check engine light on with code P0081
- Poor acceleration and decreased fuel economy reported by the driver
- Inspected wire harness connections and control solenoid
- Found faulty control solenoid
- Replaced control solenoid and cleared codes
- Issue persisted after clearing codes
Other OBD2 Codes + Test Results
- P0081: Intake Valve Control Solenoid Circuit B2
- No additional OBD2 codes mentioned
Mechanic suggestions
- Verify resistance in the wire harness and connections
- Monitor solenoid during engine operation to assess duty cycle
Final fix
Replaced the faulty control solenoid. Cleared codes, but issue persisted. Further investigation revealed no faults in the wire harness. Continued monitoring of the solenoid during engine operation showed a constant signal from the PCM. Suspected fault with the PCM itself. Replaced the PCM, cleared codes, and issue resolved. Vehicle returned to normal operation.
Case #3: Ford P0081
Vehicle information
2015 Ford Explorer Limited 3.5L V6
Issue + repair history
- Check engine light on with code P0081
- Poor acceleration and decreased fuel economy reported by the driver
- Inspected wire harness connections and control solenoid
- Found short to power in the wire harness
- Repaired short to power and cleared codes
- Issue persisted after clearing codes
Other OBD2 Codes + Test Results
- P0081: Intake Valve Control Solenoid Circuit B2
- No additional OBD2 codes mentioned
Mechanic suggestions
- Recheck wire harness connections for any further issues
- Test resistance in the wire harness and connections
- Monitor solenoid during engine operation to assess duty cycle
Final fix
Discovered a short to power in the wire harness. Repaired the short, reconnected wire harness, and cleared codes. Issue resolved, and vehicle returned to normal operation.
How to diagnose P0081
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Diagnostic Step | Brief Explanation |
|---|---|
| Check wire harness connections | Look for corrosion or damage that could mess with the signal. |
| Test resistance | Make sure electricity flows through wires and parts as it should. |
| Monitor solenoid operation | See if the solenoid is opening and closing properly while driving. |
| Inspect for shorts to power | Find places where wires might be getting too much electricity. |
| Replace faulty parts | Swap out any parts that aren’t working right, like the solenoid or PCM. |
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko