Manifold Air Pressure/Mass Air Flow Throttle Position Correlation
The PCM has detected an excessive degree of variation in the value of the throttle position sensor, triangulated with the mass air flow sensor, and manifold air pressure sensor.
Code Set Parameters
When the throttle degree, the air flow, volume, and/or manifold air pressure differ by more than 15-percent of the manufacturer’s referenced amount, then a trouble code will be stored and a service engine soon lamp illuminated.
These can include poor or hesitant acceleration, decreased engine performance, and reduced fuel efficiency. These will also be accompanied by a service engine soon lamp.
Probable causes include a large vacuum leak, a cracked or disconnected air intake pipe, clogged air filter, or faulty TPS, MAF, or MAP sensor. PCM failure is also possible but rare.
The MAF and/or MAP sensors are often condemned in error when the TPS is the culprit.
- Begin your diagnosis by visually inspecting all wiring and connectors
- Look for shorted or burned wiring and replace circuitry and connectors as required
If the system wiring, connectors, and components appear to be in normal working order, connect the scanner to the diagnostic connector and record all stored trouble codes and freeze frame data
- This information can be extremely helpful in diagnosing intermittent conditions that may have contributed to this code being stored
- After the codes are cleared, operate the vehicle to see if the code returns
- If the code fails to immediately return, you may have an intermittent condition
- Intermittent conditions can prove to be quite a challenge to diagnose and in extreme cases may have to be allowed to worsen before a correct diagnosis can be made.
Carefully exhaust all diagnostic procedures associated with this code prior to condemning any particular component
- Techs report that “glitchy” TPS sensors frequently operate normally when at normal operating temperature but fail when cold
- Engine condition, vacuum leaks, and the presence of unmetered air should also be taken into consideration.