Fuel & air metering · Powertrain · generic (SAE-defined)
P0068: MAP/MAF - Throttle Position Correlation
P0068 means the engine computer found that the airflow reading from the manifold absolute pressure (MAP) or mass air flow (MAF) sensor does not agree with what throttle position says it should be.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0068 sets
The powertrain control module (PCM) predicts how much air should enter the engine from throttle position and engine speed, then compares that to what the MAP or MAF sensor reports. If the measured airflow is too high or too low for the throttle opening, P0068 sets. A large vacuum leak, for example, lets in air the throttle did not meter. The thresholds are manufacturer-specific.
Common causes of P0068
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Vacuum leak or unmetered air leak after the MAF sensor
- Dirty or failing MAF sensor
- Faulty MAP sensor or leaking MAP vacuum hose
- Dirty or failing electronic throttle body
- Throttle position sensor fault
- Cracked intake duct or loose clamp
P0068 symptoms
- Check engine light on
- Reduced power or limp mode
- Rough or high idle
- Hesitation or stalling
- Electronic throttle control warning light on some vehicles
How P0068 is diagnosed
- Scan for codes; MAF, MAP and throttle codes help narrow the cause
- Inspect intake ducting, PCV hoses and vacuum lines for leaks
- Smoke test the intake for vacuum leaks
- Compare MAF, MAP and throttle position readings at idle and during snap throttle
- Inspect and clean the throttle body
- Test MAF and MAP sensor wiring and signals
Typical fixes for P0068
- Repair vacuum or intake air leaks
- Clean or replace the MAF sensor
- Replace the MAP sensor or its vacuum hose
- Clean or replace the throttle body
- Perform a throttle relearn if required after repairs
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Manufacturer notes
Commonly reported on GM vehicles, often linked to vacuum leaks or throttle body issues. Definitions can vary by manufacturer; check factory service information.
Related codes & warning lights
P0068 FAQ
What does code P0068 mean?
P0068 means the engine computer found that the airflow reading from the manifold absolute pressure (MAP) or mass air flow (MAF) sensor does not agree with what throttle position says it should be. The standard definition is "MAP/MAF - Throttle Position Correlation."
Can I drive with a P0068 code?
Drive only as needed to get it repaired. On many vehicles this code puts the engine into a reduced-power mode, which can make merging and highway driving unsafe.
Can a dirty throttle body cause P0068?
Yes. Carbon buildup changes how much air passes at a given throttle angle, which can make airflow disagree with throttle position.
Why does P0068 trigger reduced power?
When airflow and throttle position disagree, the PCM cannot trust its throttle control, so it limits power as a safety measure.
Keep researching
Engine guides by brand (known issues, specs)
More fuel & air metering codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
- California Air Resources Board — On-Board Diagnostic (OBD) Program
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.