Fault code P201D – intake manifold air control actuator internal malfunction (Bank 1)

Fault code P201D is called “Intake Manifold Air Control Actuator Internal Malfunction (Bank 1)” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P201D

This Diagnostic Trouble Code (DTC) is a generic powertrain code. The P201D error is considered a general code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly depending on the model.

Fault code P201D – intake manifold air control actuator internal malfunction (Bank 1)

The intake manifold is designed to increase or decrease the rate at which the intake air flows through it. Adjustment is accomplished by means of a control actuator.

The degree of opening depends on engine speed and other operating conditions. Such as throttle position and speed. Also, environmental factors such as atmospheric pressure and ambient temperature.

A high degree of control is required for the system to work properly. Code P201D is mainly concerned with electrical open circuits in the actuator control circuit. But vacuum leaks, can also cause this code in some cases. Because the sensors may produce a signal that is not what is desired.

In some vehicles, this code is retained and the warning light comes on during the first failure cycles. But more often than not, several failure cycles occur before the warning light illuminates.

If the PCM detects an internal fault anywhere in the actuator control system. Which prevents effective communication between the PCM and the actuator, it will set code P201D and turn on the warning lamp.

Symptoms of vehicle malfunctions

The main signal that an error P201D has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

  1. Check engine control lamp on the control panel will light up (the code will be recorded in the ECM memory as a fault).
  2. Poor engine operation at idle.
  3. Reduced torque, and loss of power at low engine speeds.
  4. Jerky and unstable engine operation during acceleration.

Error P201D is considered serious, as there is a possibility of engine damage due to improper operation of the engine.

Factors that can cause this error code

The error code P201D can mean that one or more of the following problems have occurred:

  • Faulty actuator control system.
  • Damaged, shorted or corroded wires and connectors.
  • Damaged vacuum lines.
  • Sometimes the cause is a faulty PCM module.

How to fix or reset OBD-2 code P201D

Some suggested steps for troubleshooting and fix the error code P201D:

  1. Connect the OBD-II scanner to the vehicle’s diagnostic connector and read all stored data and error codes.
  2. Clear the error codes from the computer memory.
  3. Test-drive the vehicle to see if the error appears again.
  4. If the code appears again, visually inspect the electrical wires, connectors, and vacuum lines for wear and damage.
  5. Measure the voltage in the actuator control circuit using a multimeter.
  6. Repair or replace any damaged or defective components.

Diagnose and repair of problems

Perform a thorough visual inspection of all wiring and lines. Look for damaged, burned, disconnected or corroded wiring and connectors. Make repairs if necessary.

Inspect all vacuum lines for cracks, chips, hardening, or perforation. Make sure all connections are tight and all vacuum check valves allow air flow only in the direction shown. Perform repairs as needed.

If code P201D remains, but there is no visible wiring damage, test with a voltmeter for resistance, ground, and reference voltage. Compare all readings with the values given in the manual. To ensure that all electrical values are within the ranges specified by the manufacturer.

Remove all codes after replacement, test drive to see if the code returns.

By following these steps, you’ve almost certainly resolved the P201D code. But if the error hasn’t gone away, a faulty PCM may be causing the problem. However, PCM failure is an extremely rare occurrence, the most likely cause being intermittent electrical failure.

On which vehicles does this problem occur most frequently

Fault code P201D can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

  • Jeep (Grand Cherokee)
  • Mercedes-Benz (W203)
  • Opel (Astra)
  • Smart

Fault code P201D can sometimes be found with other errors. The most common are the following: P201B, P201C, P201E, P20F8, P20F9.


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