P061B Internal Control Module Torque Calculation Performance
OBD-II Trouble Code Technical Description
Internal Control Module Torque Calculation 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 Mazda, Ford, Mercedes Benz, Chevy, etc.
When a code P061B is stored, it means that the powertrain control module (PCM) has detected an internal performance error in the engine torque monitoring system. Other controllers may also detect an internal PCM performance error (with the engine torque monitoring system) and contribute to a P061B being stored.
Internal control module monitoring processors are responsible for various controller self-test duties and overall internal control module accountability. Engine torque 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 torque monitoring system.
Engine torque is monitored (by the PCM and other controllers) using input signals from the mass air flow (MAF) sensor and the accelerator pedal position (APP) sensor (also called the pedal position sensor). Desired or approximate required engine torque is calculated using the APP sensor and actual engine torque is calculated using data from the MAF sensor.
Whenever the ignition is on and the PCM is energized, internal engine torque 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 a discrepancy in desired torque and actual torque (more than 50-Newton meters for more than 1-second) with the engine RPM above 5,000 RPM and volumetric efficiency greater than 16-percent, a code P061B will be stored and a malfunction indicator lamp (MIL) may be illuminated. Multiple failure cycles may be necessary for MIL illumination, depending upon the perceived severity of the malfunction.
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 P061B 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 P061B trouble code may include:
Hesitation or stumble upon acceleration Acceleration becomes unresponsive Diminished fuel efficiency MAF or throttle actuator codes are also presentWhat are some of the common causes of the code?
Causes for this code may include:
Bad throttle valve control servo Open or shorted circuit in the throttle valve control servo circuit Clogged air filter element Debris on the MAF sensor hot wire Defective APP/MAF sensor Corroded electrical 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 APP/MAF sensor and the PCMWhat are some P061B troubleshooting steps?
Even to the most experienced and well-equipped professional technician, diagnosing a code P061B 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 P061B. Also, if there are MAF/APP sensor or throttle position sensor
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