Fuel and air

P006A — MAP and Mass Air Flow Sensor Correlation Fault (Bank 1)

Severity: medium Drive with care, to a shop

What P006A means

The engine control unit compares intake manifold pressure from the MAP sensor with the airflow reported by the MAF sensor, and checks both against what it expects for the current RPM and throttle angle. When the two readings disagree, it stores P006A. The cause can be a bad sensor, an air leak or a wiring problem, and the code alone doesn't say which sensor is wrong.

Symptoms

  • Check Engine Light on
  • Hesitation or stumbling when accelerating
  • Rough idle, sometimes stalling
  • Reduced power
  • Poor fuel economy
  • Abnormal fuel trim values (short/long term)

Possible causes

  1. Dirty or failing mass air flow (MAF) sensor
  2. Faulty MAP sensor
  3. Air or vacuum leak in the intake after the MAF sensor
  4. Damaged wiring or corroded or loose connectors at the MAP or MAF sensor
  5. Badly clogged air filter restricting airflow
  6. Rarely, PCM software issue or module fault

How to diagnose

  1. Scan for all codes and freeze frame data; look for related MAF, MAP, throttle or fuel trim codes
  2. Inspect the air filter and the intake duct between the MAF sensor and throttle body for cracks, loose clamps and bad joints
  3. Check vacuum hoses and the intake manifold gasket for leaks, using a smoke machine if possible
  4. Watch live MAF and MAP data at idle and under load and compare with expected values for the engine
  5. Review fuel trims; a high positive trim at idle often points to an air leak
  6. Test power, ground and signal wires for both sensors and check the connectors for corrosion
  7. Clean the MAF sensor with proper MAF cleaner and retest; replace it if the readings still look wrong
  8. Check the MAP sensor voltage with key on engine off and with the engine running

Common fixes

  • Clean or replace the MAF sensor
  • Replace a faulty MAP sensor
  • Repair intake or vacuum leaks: hoses, ducts, gaskets
  • Repair wiring and connectors
  • Replace the air filter
  • Update PCM software or replace the module (rare)

Questions and answers

What does P006A mean?

It means the manifold pressure reading from the MAP sensor doesn't match the airflow reading from the MAF sensor. The computer can't tell which one is correct, so both sensors and the intake tract need to be checked.

Can I drive with code P006A?

Briefly and carefully, such as to a repair shop, usually yes. Don't drive long term: the wrong mixture hurts fuel economy and power and can cause stalling.

Will cleaning the MAF sensor fix it?

Sometimes, if the sensor is just dirty. If the real problem is an air leak, a bad MAP sensor or wiring, cleaning won't help, so check the intake system and fuel trims first.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.