P061D Internal Control Module Engine Air Mass Performance
OBD-II Trouble Code Technical Description
Internal Control Module Engine Air Mass Performance
What does that mean?
This generic powertrain diagnostic trouble code (DTC) typically applies to many OBD-II vehicles. That may include but is not limited to vehicles from Ford, Mazda, Chevrolet, Lincoln, etc.
When a code P061D is stored, it means that the powertrain control module (PCM) has detected an internal performance error in the engine air mass (mass air flow - MAF) monitoring system. Other controllers may also detect an internal PCM performance error (with the engine RPM monitoring system) and contribute to a P061D being stored.
Internal control module monitoring processors are responsible for various controller self-test duties and overall internal control module accountability. Engine air mass calculation system input and output signals are subject to self-test and are monitored constantly by the PCM and other related controllers. The transmission control module (TCM), traction control module (TCSM), and other controllers are subject to interaction with the engine air mass monitoring system.
Engine air mass is monitored (by the PCM and other controllers) using input signals from the MAF sensor/s. Desired engine MAF is programmed into the PCM and other controllers. Actual engine air mass is calculated using input data from the MAF sensor, as well as the throttle position sensor (TPS), and other engine and transmission sensors. Desired engine air mass is then compared with actual engine air mass. After desired and actual engine air mass are compared, the PCM makes the necessary adjustments to fuel delivery and ignition timing.
Whenever the ignition is on and the PCM is energized, internal engine RPM monitoring self-tests are initiated. In addition to running internal controller self-tests, the controller area network (CAN) also compares signals from each individual module to ensure that all controllers are functioning properly. These tests are performed simultaneously.
If the PCM detects an internal error in desired engine air mass and actual engine air mass (which exceeds the maximum allowable threshold), a code P061D will be stored and a malfunction indicator lamp (MIL) may be illuminated. Multiple ignition cycles (with a failure) may be required for MIL illumination.
Photo of a PCM with the cover removed:
What is the severity of this DTC?
Internal control module processor codes should be categorized as severe. A stored code P061D could result in serious drivability and fuel efficiency issues, suddenly and without warning.
What are some of the symptoms of the code?
Symptoms of a P061D trouble code may include:
Hesitation or stumble upon acceleration Engine misfire Diminished fuel efficiency Engine misfire codes may also be presentWhat are some of the common causes of the code?
Causes for this code may include:
Defective MAF sensor Corroded MAF sensor connector Defective PCM or PCM programming error Open or shorted circuit or connectors in the CAN harness Insufficient control module ground Open or shorted circuits between the MAF sensor and the PCMWhat are some P061D troubleshooting steps?
Even to the most experienced and well-equipped professional technician, diagnosing a code P061D can prove to be quite a challenge. There is also the issue of reprogramming. Without the necessary reprogramming equipment, it will be impossible to replace a defective controller and complete a successful repair.
If there are ECM/PCM power supply codes present, they will obviously need to be rectified before attempting to diagnose a P061D. Also, if MAF sensor or throttle position sensor (TPS) codes are present, these must be diagnosed and repaired first.
Follow manufacturer's recommendations for testing MAF
Read: 43
