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P0068 Code Explained: MAP/MAF–Throttle Position Correlation Causes, Symptoms & Fixes

P0068 code displayed on an OBD-II scanner with the mass airflow sensor, manifold pressure sensor, electronic throttle body, and intake airflow path highlighted.

If your OBD-II scanner displays P0068, your vehicle’s Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected that the measured airflow or intake-manifold pressure does not agree with the reported throttle position.

The generic OBD-II definition for P0068 is:

MAP/MAF–Throttle Position Correlation

Depending on the vehicle and scan tool, the description may appear as:

Manufacturers may word the fault differently, but the basic problem is the same: the PCM has calculated how much air should be entering the engine at a given throttle opening, engine speed, temperature, and load, and the actual sensor data does not match that expectation. Factory Volkswagen and Audi diagnostic references identify P0068 as a MAP/MAF-to-throttle-position plausibility fault, while Mitsubishi service information lists intake leaks, MAF contamination, MAF-system failure, and ECM failure among likely causes.

Common causes include:

P0068 can cause rough idle, hesitation, stalling, reduced engine power, poor acceleration, increased fuel consumption, or hard starting. Some vehicles may enter a reduced-power or limp-home mode because the PCM can no longer confidently determine how much air is entering the engine.

For additional diagnostic information, visit:

P0068 Quick Facts

ItemInformation
OBD-II CodeP0068
DescriptionMAP/MAF–Throttle Position Correlation
CategoryPowertrain
SystemFuel and Air Metering
Main ComponentsMAF Sensor, MAP Sensor and Throttle Body
SeverityModerate to High
Safe to Drive?Sometimes, depending on symptoms
Typical Repair Cost$75–1,200

What Does P0068 Mean?

P0068 means the PCM has detected that one or more of the following values do not agree:

When the throttle plate opens, airflow should increase and intake-manifold pressure should change in a predictable way.

For example:

  1. The accelerator pedal is pressed.
  2. The throttle plate opens.
  3. More air enters the engine.
  4. MAF readings should increase.
  5. MAP readings should move closer to atmospheric pressure.
  6. Engine load and fuel delivery should increase.

If the throttle is reported as mostly closed while the MAF sensor reports heavy airflow, the data is implausible.

Likewise, if the throttle opens significantly but the MAF or MAP readings barely change, the PCM may conclude that a sensor, throttle body, wiring circuit, or intake component is malfunctioning.

The PCM does not necessarily know which component is wrong. It only knows that the numbers disagree.

What Does MAP/MAF–Throttle Position Correlation Mean?

“Correlation” means the PCM is comparing several related sensor signals to determine whether they make sense together.

The main inputs are typically:

Mass Airflow Sensor

The MAF sensor measures the amount of air entering the engine.

Its reading may be displayed as:

The PCM uses this information to calculate fuel delivery and engine load.

Manifold Absolute Pressure Sensor

The MAP sensor measures pressure inside the intake manifold.

At idle, manifold vacuum is generally high and absolute pressure is comparatively low.

As the throttle opens:

Throttle Position Sensor

The throttle position sensor, usually built into an electronic throttle body, reports how far the throttle plate is open.

Many electronic throttle systems use two internal throttle-position signals that move in a predictable relationship for safety.

The PCM compares the throttle position with MAF and MAP data. If the calculated airflow does not match the throttle opening, it may set P0068.

Why Does the PCM Compare These Sensors?

Modern engine controls depend heavily on accurate airflow calculations.

The PCM uses airflow and throttle data to control:

Using several sensors allows the PCM to identify implausible data.

If the throttle is nearly closed, airflow should normally be relatively low.

If the throttle is wide open, airflow and manifold pressure should increase significantly.

When those relationships stop making sense, the PCM cannot reliably calculate engine load.

P0068 is therefore less about one individual sensor and more about the PCM saying, “At least one of these numbers is lying.”

How the PCM Detects P0068

The exact enable conditions differ by manufacturer, but the PCM may monitor the correlation while the engine is:

The PCM may calculate expected airflow using:

It then compares the expected value with the actual MAF or MAP sensor reading.

P0068 may be stored when:

Volkswagen reference material describes P0068 as a plausibility fault involving calculated engine load, while Kia has issued a technical bulletin addressing certain P0068 cases through electronic-throttle cleaning and ECM software improvement.

P0068 vs Related Airflow Codes

CodeDescription
P0068MAP/MAF–Throttle Position Correlation
P0069Manifold Absolute Pressure–Barometric Pressure Correlation
P0101Mass or Volume Airflow Circuit Range/Performance
P0106MAP/BARO Circuit Range/Performance
P0121Throttle/Pedal Position Sensor Range/Performance
P0171System Too Lean Bank 1
P0174System Too Lean Bank 2
P0507Idle Control System RPM Higher Than Expected
P2279Intake Air System Leak

P0068 may appear with several of these codes because an intake leak or incorrect airflow reading can affect multiple PCM calculations.

Symptoms of P0068

Possible P0068 symptoms include:

Symptoms vary depending on which signal is inaccurate and whether the engine has a major intake leak.

A lightly contaminated MAF sensor may cause only a Check Engine Light and minor hesitation.

A disconnected intake hose or failing electronic throttle body may produce severe drivability problems almost immediately.

Common Causes of P0068

1. Vacuum Leak

A vacuum leak allows air to enter the engine without following the expected path.

Possible leak locations include:

Unmetered air can make actual engine airflow disagree with the MAF and throttle-position readings.

2. Loose or Cracked Intake Tube

The intake duct between the MAF sensor and throttle body may be:

Air entering through a crack after the MAF sensor is not measured properly.

This can produce:

Always inspect the underside of flexible intake boots. They have an impressive habit of hiding cracks precisely where nobody can see them.

3. Dirty Mass Airflow Sensor

Dust, oil vapor, filter oil, or debris can contaminate the MAF sensing element.

A contaminated MAF sensor may:

Mitsubishi service guidance for P0068 specifically directs technicians to inspect for foreign material around the MAF sensor and verify that its output rises with engine speed.

4. Faulty Mass Airflow Sensor

The MAF sensor may fail electrically even when it appears clean.

Possible faults include:

A replacement MAF sensor should match the vehicle’s exact calibration.

5. Dirty Throttle Body

Carbon deposits can accumulate around the throttle plate and bore.

This can cause:

Kia has issued a service bulletin for certain vehicles that combines electronic-throttle cleaning with ECM logic improvement when P0068 appears with related airflow codes.

6. Faulty Electronic Throttle Body

The throttle body may fail because of:

A defective electronic throttle body can cause P0068 even when the MAF and MAP sensors are operating correctly.

7. Throttle Body Not Relearned

Some vehicles require a throttle-body adaptation or idle relearn after:

If the learned closed-throttle position is incorrect, the PCM may detect implausible airflow.

8. Faulty MAP Sensor

A MAP sensor that reports incorrect manifold pressure can disrupt calculated load.

Possible causes include:

Compare MAP readings with barometric pressure when the key is on and the engine is off.

The readings should generally be reasonably close because the engine is not producing manifold vacuum.

9. Restricted MAP Sensor Passage

On some engines, the MAP sensor communicates with the intake manifold through a small port or passage.

Carbon, oil, or sludge may block this passage and cause the sensor to respond slowly or inaccurately.

The sensor itself may be perfectly functional while the pressure never reaches it correctly.

10. Faulty Throttle Position Sensor

On many vehicles, the throttle position sensor is integrated into the throttle body.

A faulty sensor may produce:

If the PCM believes the throttle plate is at a different angle than it actually is, P0068 may be stored.

11. PCV System Fault

A failed PCV valve, torn diaphragm, disconnected hose, or cracked breather pipe can create a significant intake leak.

Possible symptoms include:

Certain Audi applications may set P0068 when the oil filler cap is loose or installed incorrectly because the crankcase ventilation system becomes an intake leak.

12. Loose or Incorrectly Installed Oil Filler Cap

This sounds almost too simple, but on engines with tightly controlled crankcase ventilation, a loose oil cap can introduce enough unmetered air to upset airflow plausibility.

Audi has published technical information linking an incorrectly installed oil filler cap with P0068, P2279, and P0507 on certain vehicles.

Before replacing expensive sensors, confirm that the oil cap is:

13. Brake-Booster Vacuum Leak

A leaking brake booster or vacuum hose can introduce a large amount of unmetered air.

Possible clues include:

Because brake assistance may be affected, this condition should be treated seriously.

14. Stuck EVAP Purge Valve

An EVAP purge valve stuck open can allow uncontrolled vapor and airflow into the intake manifold.

Possible symptoms include:

Pinching or blocking the purge line temporarily during diagnosis may reveal whether the valve is affecting airflow.

15. Intake Restriction

Restricted airflow before the throttle body can also produce implausible values.

Possible causes include:

A mouse condominium inside the airbox remains unlikely, but not unprecedented.

16. Turbocharger or Intercooler Leak

On turbocharged engines, a leak in the pressurized intake system may cause airflow measured by the MAF sensor to differ from the air that actually reaches the engine.

Inspect:

A smoke or pressure test is often required because some leaks open only under boost.

17. Sensor Wiring Damage

The MAF, MAP, or throttle-position circuits may suffer from:

Because several sensors may share a five-volt reference or sensor ground, one damaged component can affect multiple readings.

18. Poor Electrical Ground

A weak engine, chassis, or sensor ground may alter voltage signals.

Inspect:

Multiple unrelated sensor codes may indicate a shared ground or reference-voltage problem.

19. Incorrect Aftermarket Air Intake

Some aftermarket intake systems alter:

Changing the MAF housing dimensions can change the sensor’s airflow calibration even when the sensor itself is functioning correctly.

20. ECM Software or Calibration Issue

Some P0068 complaints are related to overly sensitive diagnostic logic rather than a failed mechanical part.

Kia has documented certain applications where ECM reprogramming and throttle-body cleaning are prescribed for P0068 with related MAF and MAP codes.

Always check manufacturer technical service bulletins before replacing expensive components.

21. ECM Failure

The ECM may incorrectly process airflow or throttle data because of an internal fault.

ECM failure is uncommon and should only be suspected after verifying:

Is P0068 Serious?

P0068 is generally considered a moderate- to high-severity code.

The severity depends on the symptoms.

A vehicle that runs normally with only a Check Engine Light may remain usable for a short period.

A vehicle with:

should be diagnosed immediately.

Because the PCM uses airflow and throttle data to calculate engine load, inaccurate information can affect fuel delivery, ignition timing, electronic throttle control, and transmission operation.

Can You Drive With P0068?

You may be able to drive with P0068 if:

Avoid driving if:

A large intake leak may cause the engine to run excessively lean, while a faulty sensor can cause incorrect fueling.

Neither situation improves through optimism.

How to Diagnose P0068

Step 1: Scan for Additional Codes

Check for related codes involving:

Record freeze-frame data before clearing anything.

Important values include:

Step 2: Inspect the Intake System

Inspect everything between the air filter and intake manifold.

Look for:

Flex rubber intake ducts by hand because cracks may only open when the duct moves.

Step 3: Inspect the PCV System

Check:

Listen for:

Excessive crankcase vacuum may indicate a failed PCV diaphragm.

Step 4: Perform a Smoke Test

A smoke test is one of the most effective ways to locate:

Seal the intake according to the manufacturer’s procedure and use appropriate pressure.

Do not pressurize a plastic intake system like you are testing industrial plumbing.

Step 5: Inspect and Clean the MAF Sensor

Remove the MAF sensor only if the manufacturer permits it.

Inspect for:

Use only dedicated MAF-sensor cleaner.

Do not use:

Allow the sensor to dry completely before reinstalling it.

Step 6: Monitor MAF Data

Use a scan tool to observe MAF readings:

The signal should generally increase smoothly as airflow rises.

A reading that is:

may indicate contamination, wiring trouble, an air leak, or sensor failure.

Exact specifications vary by engine size and design.

Step 7: Check MAP and Barometric Pressure

With the key on and engine off, compare:

MAP and BARO should generally be reasonably close because the intake manifold is not under engine vacuum.

At idle, MAP pressure should decrease as manifold vacuum develops.

If MAP readings do not respond correctly:

Step 8: Inspect the Throttle Body

Inspect the throttle body for:

Do not force an electronically controlled throttle plate unless the service procedure allows it.

Some throttle motors and gears can be damaged by aggressive manual movement.

Step 9: Clean the Throttle Body

If contamination is present, clean the throttle body using the manufacturer-approved procedure.

Pay attention to deposits around:

After cleaning, perform any required:

Cleaning without relearning may leave the PCM confused about the new closed-throttle airflow.

Step 10: Monitor Throttle Position

Use scan data to monitor:

The values should change smoothly and maintain the manufacturer-specified relationship.

Watch for:

Step 11: Check Fuel Trims

Monitor short-term and long-term fuel trims.

Large positive fuel trims may indicate:

Large negative fuel trims may indicate:

Compare fuel trims:

A vacuum leak often produces worse positive trims at idle that improve as engine speed increases.

Step 12: Check the Brake Booster

Inspect the brake-booster hose and check valve.

Listen for air leaks while pressing the brake pedal.

If engine idle changes significantly or braking assistance is reduced, inspect the booster system carefully.

A brake-booster leak is both an engine-performance problem and a safety concern.

Step 13: Test the EVAP Purge Valve

Check whether the purge valve is leaking when commanded closed.

A purge valve stuck open may introduce uncontrolled vapor and air into the intake manifold.

Possible tests include:

Follow manufacturer instructions.

Step 14: Inspect Turbocharger Plumbing

On turbocharged vehicles, perform a smoke or pressure test of:

Look for oil staining around boost leaks.

A hose may remain sealed at idle and open only when pressurized.

Step 15: Check Sensor Power and Grounds

Use a wiring diagram to identify:

Check for:

Do not apply battery voltage to a five-volt sensor circuit.

That turns diagnosis into module replacement with remarkable efficiency.

Step 16: Perform a Wiggle Test

While monitoring live sensor data, gently move the wiring harness near:

Watch for:

An intermittent wiring fault may only appear when the engine moves under load.

Step 17: Check for Technical Service Bulletins

Search manufacturer service information using:

Possible factory corrections may include:

Factory bulletins show that P0068 can sometimes result from system-specific issues such as throttle contamination, software logic, or a crankcase leak rather than a universally failed sensor.

Step 18: Perform Throttle Adaptation

If required, perform the manufacturer’s throttle-body relearn procedure.

This may require:

Do not assume battery disconnection will complete the correct adaptation.

Step 19: Replace the Confirmed Failed Component

Possible repairs include:

Avoid replacing all three sensors simply because all three appear in the code description.

The PCM has identified a disagreement, not organized a sensor clearance sale.

Step 20: Verify the Repair

After completing repairs:

  1. Clear all diagnostic trouble codes.
  2. Perform any required throttle relearn.
  3. Start the engine.
  4. Monitor idle quality.
  5. Compare MAP, MAF, and throttle data.
  6. Check short- and long-term fuel trims.
  7. Road-test the vehicle.
  8. Complete the manufacturer’s drive cycle.
  9. Verify readiness monitors.
  10. Confirm P0068 does not return.

Common Repairs and Costs

RepairEstimated Cost
Tighten or replace oil filler cap$0–60
Replace vacuum hose$50–200
Repair intake duct$75–300
Smoke-test intake system$100–250
Clean MAF sensor$50–150
Replace MAF sensor$150–500
Replace MAP sensor$125–400
Clean throttle body$100–300
Throttle-body relearn$75–200
Replace electronic throttle body$400–1,200
Replace PCV valve or assembly$100–600
Repair intake manifold leak$300–1,200
Repair wiring or connector$100–500
ECM software update$100–300
Replace ECM$1,000–2,500+

Costs vary depending on the vehicle, labor rate, access, and whether the failed sensor is integrated into a larger assembly.

Common Diagnostic Mistakes

Avoid these common P0068 diagnostic mistakes:

P0068 does not automatically mean the MAF sensor is defective.

It means the PCM sees a mathematical argument between several sensors and would like the technician to determine which one started it.

Vehicles Commonly Affected

P0068 is a generic powertrain code and may appear on many OBD-II-equipped vehicles.

Applications may include certain:

Manufacturer-specific failure patterns vary.

Examples documented in factory information include:

Always diagnose the exact vehicle rather than assuming every P0068 has the same cause.

How to Prevent P0068

Reduce the likelihood of P0068 by:

Frequently Asked Questions

What does P0068 mean?

P0068 means the PCM has detected that the MAP or MAF sensor data does not match the reported throttle position.

What causes P0068 most often?

Common causes include:

Is P0068 serious?

P0068 can be moderately or highly serious.

A minor airflow discrepancy may cause only a Check Engine Light, while a major intake leak or throttle-body problem can cause stalling or reduced power.

Can I drive with P0068?

You may be able to drive briefly if the engine runs normally.

Do not drive if the vehicle stalls, enters reduced-power mode, has unpredictable throttle response, or loses brake assistance.

Can a vacuum leak cause P0068?

Yes.

A vacuum leak introduces air that the PCM may not expect or properly measure, causing airflow and throttle-position data to disagree.

Can a dirty MAF sensor cause P0068?

Yes.

Contamination can cause the MAF sensor to underreport, overreport, or respond slowly to airflow changes.

Can a dirty throttle body cause P0068?

Yes.

Carbon around the throttle plate can change actual airflow and prevent the throttle from moving as expected.

Can a loose oil cap cause P0068?

Yes, on certain engines.

Audi has documented P0068 associated with an incorrectly installed oil filler cap because it creates a crankcase ventilation leak.

Can a bad PCV valve cause P0068?

Yes.

A torn PCV diaphragm or leaking hose can introduce significant unmetered air.

Will cleaning the throttle body fix P0068?

It may if carbon buildup is affecting throttle airflow or movement.

A throttle relearn may also be required after cleaning.

Will replacing the MAF sensor fix P0068?

Only if testing confirms the MAF sensor is inaccurate.

Replacing it without checking for leaks, wiring faults, MAP problems, or throttle-body contamination may not solve the code.

Can an aftermarket air intake cause P0068?

Yes.

An incorrect MAF housing diameter, turbulent airflow, poor sealing, or oiled-filter contamination can alter MAF readings.

Can P0068 cause limp mode?

Yes.

Some vehicles reduce throttle response or engine power when airflow and throttle data become implausible.

Can P0068 cause high idle?

Yes.

A vacuum leak, PCV fault, dirty throttle body, or incorrect throttle adaptation may produce a high idle.

Can P0068 cause poor fuel economy?

Yes.

Incorrect airflow data can cause improper fuel delivery and inefficient combustion.

Can P0068 cause an emissions failure?

Yes.

An active Check Engine Light or incomplete readiness monitors may prevent the vehicle from passing inspection.

How much does P0068 cost to repair?

A simple loose hose or oil cap may cost little or nothing to correct.

A MAF sensor, MAP sensor, PCV assembly, intake manifold repair, or electronic throttle body may cost several hundred dollars or more.

Final Thoughts

The P0068 code means the PCM has detected that the engine’s MAP or MAF readings do not correlate with throttle position.

The most common causes include vacuum leaks, damaged intake tubing, a contaminated MAF sensor, a dirty throttle body, PCV-system faults, an inaccurate MAP sensor, wiring trouble, or incorrect throttle adaptation.

Start with the simple checks:

Then use live scan data to compare:

A smoke test, throttle inspection, sensor-circuit testing, and service-bulletin search should follow before replacing parts.

Most importantly, do not treat P0068 as an automatic MAF-sensor replacement order. The code says several airflow calculations disagree. It does not say which component deserves to be launched into the nearest trash can.

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