P2078 OBD-II Trouble Code: Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P2078 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2078 code

P2078 is a diagnostic trouble code (DTC) for "Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P2078 DIAGNOSTIC Get a fair and transparent estimate upfront

P2078 code definition

Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High

What the P2078 code means

This code will set if the Engine Control Module (ECM), or Powertrain Control Module (PCM), detects a problem with the position of the IMT valve.

What causes the P2078 code?

This code is set when the ECM sees a higher than expected voltage from the IMT position sensor. This can occur if the circuit has a short to power or a bad ground.

What are the symptoms of the P2078 code?

How does a mechanic diagnose the P2078 code?

The first step would be to connect a scan tool to the vehicle's OBD II connector, check for codes and observe the scan tool data for the IMT valve. Most vehicles have the capability to command the IMT valve motor to move. This should be done while watching the scan tool data and observing the valve itself. Often times it is necessary to do some disassembly to physically check the valve and sensor.

Common mistakes when diagnosing the P2078 code

Some IMT valves are vacuum actuated and others are electrically actuated. Vacuum lines to the vacuum actuated valves frequently plug, collapse or break. Failing to thoroughly inspect the vacuum lines can lead to misdiagnosis of the IMT valve.

Some disassembly is often necessary to see if the valve flap has broken away from its shaft. If this happens, all data and the valve motor will work, but drivability issues will still exist. A mechanic could dismiss this code as erroneous and suspect other components as the problem.

How serious is the P2078 code?

This code will likely cause drivability problems that the owner will find annoying. Outside of drivability issues this code will not cause damage to the motor or be unsafe for the passengers.

What repairs can fix the P2078 code?

  • Replacing the IMT valve (the sensor that this code indicates is the problem is most often part of the IMT valve assembly and will be replaced as a single unit)

  • Repairing wiring to the control circuit

  • Repairing vacuum lines that may be plugged or leaking

Additional comments for consideration regarding the P2078 code

This system is designed to enable better fuel mileage and performance in modern vehicles. The IMT valve directs the intake air flow from a long path at low RPM’s (Revolutions Per Minute) to a shorter path at higher RPM’s. This affects the MAF (Mass Air Flow) sensor’s data. The MAF, or as it is sometimes called, the MASS air flow sensor, is one of the primary sensors used by the ECM to calculate air/fuel ratio.

Need help with a P2078 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6220.

trouble codes
P2078
Check Engine Light
Intake Manifold
Sensors

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P2078 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

4,796

Rating Summary
4,411
187
47
28
123
4,411
187
47
28
123

Matthew

31 years of experience
633 reviews
Matthew
31 years of experience
Mercedes-Benz E320 - Check Engine Light is on - Williamsburg, Virginia
MATT WAS AMAZING! HE EXPLAINTED EVERYTHING SO WELL! HIS EXPERTISE AS A MECHANIC IS EVIDENT AND I HIGHLY RECOMMEND HIM.

Mario

18 years of experience
101 reviews
Mario
18 years of experience
Lexus LS430 - Check Engine Light is on - Naples, Florida
NICE GUY, COMPLETED ALL WORK PROFESSIONALLY, HE ACTUALLY OFFERED SUGGESTION AND ATTITUDE WAS THAT HE CARED UNLIKE PAST MECHANIC

Kai

12 years of experience
3 reviews
Kai
12 years of experience
Hyundai Sonata - Check Engine Light is on - Plano, Texas
Great. He was knowledgable and wasted no time getting to work. Had lots of helpful information for me

Patrick

31 years of experience
1038 reviews
Patrick
31 years of experience
Mazda CX-7 - Check Engine Light is on - Austin, Texas
Patrick is always on time and extremely knowledgeable and professional. I am quite picky when it comes to somebody working on my car and I fully trust that Patrick will do an excellent job every time.

More related articles

Symptoms of a Bad or Failing Air Cleaner Temperature Sensor
If your car is having trouble starting in the cold, the Check Engine Light comes on, or idle quality is poor, you may need to replace the ACT sensor.
How to Replace a Coolant Level Sensor
Coolant level sensors are faulty if the coolant level sensor light stays on extensively or the engine overheats without the light coming on.
P2328 OBD-II Trouble Code: Ignition Coil J Primary Control Circuit High
P2328 P2328 code definition Ignition Coil J Primary Control Circuit High What the P2328 code means P2328 is an OBD-II generic code for the Ignition Coil K Primary Control Circuit High to the Engine Control Module (ECM). This means the...

Related questions

My car is showing code P1445

Hi Emily. This is one of the common codes associated with the secondary air injection system on that particular Toyota engine. One of the valves may have failed or has contamination inside. The secondary air injection system is an emission...

How long can I drive my car with the engine light on?

Hi there. It is no good to drive a vehicle with the engine light on. The engine light is on for a sensor has picked up something that is not functioning or operating correctly. Check the computer with a scanner...

Error codes P0171 and P0374

Hello. These issues can be caused by a few things. From the codes it sounds like there may be an issue with the fuel system. It may also be an issue with the air intake system allowing too much air...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com