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Error Code P2101 is defined as Throttle Actuator Control Motor Circuit Range/Performance.
This error code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II system, especially those made since 1996 up to present. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another. This code, however, shows up more often among Ford and Nissan vehicles.
The PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) receives input to determine when and how long it needs to operate the Throttle Actuator. This input is in the form of voltage signal, which is received from the coolant temperature, intake air temperature, engine RPM, and air conditioning system pressure sensors. When the PCM receives the input, it will change the signals to the Throttle Actuator.
This code means the PCM has determined that the TAC (Throttle Actuator Control) went out of range of their circuit, causing an open circuit condition detected in the TAC motor. This error can be caused by mechanical problems, such as stuck throttle blade on the electrically driven throttle actuator. Both electrical and mechanical problems cannot be overlooked in troubleshooting of this code, especially for intermittent conditions.
Other related trouble codes include:
- P2100 Throttle Actuator “A” Control Motor Circuit Open
- P2102 Throttle Actuator “A” Control Motor Circuit Low
- P2103 Throttle Actuator “A” Control Motor Circuit High
As with other error codes, this code activates the Check Engine light and registers the error code to the vehicle’s memory system. Other symptoms include:
- Fixed idle speed
- Idle lower than normal
- Engine unable to accelerate
The symptoms of this code also usually depend on the severity of the condition, and also the problem could be either electrical or mechanical failure. Partial compensation usually means the engine has a fixed idle speed, which is usually around 1000 – 1200 RPM.
The most common cause for this code is the PCM return from the TAC is an open circuit. Other possible causes include:
- The TAC motor wires are cross-wired causing an open circuit to the ECM.
- Harness or connector has an open circuit, or the connector is loose.
How to Check
As with other error codes, diagnosing this code requires a scanner to document the code in the PCM.
The manufacturer provides a pinpoint test to verify the TAC signal, which must be used for the initial diagnosis.
The technician will usually operate the accelerator pedal while monitoring the throttle position sensors and the TAC operation.
Then, they will visually inspect the harness and connection to the TAC and look for signs of problems, and make sure the connector is on.
Then, mechanics will test the TAC as per the manufacturer’s specified pinpoint test.
How to Fix
Replacement of the TAC assembly if it fails in all pinpoint test and the problem has been verified
Repair the wiring or connector to TAC assembly
Replacement of the PCM as directed by the pinpoint test
As said in its definition, this code refers to a problem in the TAC unable to open and close the throttle plates. This means that the vehicle cannot be driven since it will not accelerate.