OBD-II Trouble Code Technical Description
The circuit for supplying voltage to the actuator is experiencing high levels of voltage.
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) that is typically found in OBD-II vehicles. This code can apply to various vehicle makes such as Dodge, Chrysler, Ford, Chevrolet, Toyota, Honda, Nissan, etc.
The ECM (Engine control module) is responsible for monitoring and adjusting numerous sensors, solenoids, actuators, valves, etc. It also ensures that all of these components are working together seamlessly to achieve desired values. This is important for optimizing the economy and performance of your vehicle. If you receive a P0659 or a related code, depending on your make and model, you may experience transmission drivability issues.
It’s worth noting that in my experience with European models, I have also seen this code as an EVAP diagnostic code. Therefore, it is important to refer to your service manual for proper diagnostic direction. In most cases, your symptoms will provide a strong indication of the systems/components that need attention to resolve the fault.
When it comes to the P0659 and related codes, the ECM detects an abnormal value within the actuator supply voltage circuit by comparing the actual values to the desired ones. If the values go beyond the desired scope, the MIL (Malfunction indicator lamp) on your instrument panel will illuminate. The ECM must monitor this fault through multiple drive cycles before illuminating the MIL. It is important to research the designation for “A” within the circuit, as it could refer to a specific wire, harness, location, etc. Always refer to OEM (Original equipment manufacturer) technical service information for accurate guidance.
Depending on the specific make and model, the TCM (Transmission control module) may also detect this code with a different description.
P0659 (Actuator Supply Voltage A Circuit High) is active when the ECM or TCM detects a high voltage condition within the actuator supply voltage “A” circuit.
What is the severity of this DTC?
Generally speaking, the severity of this DTC is set to moderate. However, since there are multiple code descriptions, caution should be exercised during diagnosis. Proper service data is necessary. If this code pertains to the transmission in your case, it is advisable to repair it as soon as possible. Continuing to use a vehicle with an active transmission code poses a risk that should be avoided.
What are some of the symptoms of the code?
Symptoms of a P0659 diagnostic code may include:
What are some of the common causes of the code?
Causes for this P0659 trouble code may include:
What are some P0659 diagnostic and troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB) for known issues with the specific vehicle.
Advanced diagnostic steps become very vehicle specific and may require the appropriate advanced equipment and knowledge to perform accurately. We include basic steps below but refer to a vehicle year/make/model/powertrain specific repair guide for specific steps for your vehicle.
Basic Step #1
The approach to diagnosing this code will depend on your make and model and the symptoms you are experiencing. Generally, the first step is to clear the codes with your scanner and drive the vehicle until the code becomes active again. Once you have identified the correct circuit/harness, inspect it for any damages. It is possible for the circuit to be routed under the vehicle where it can be damaged by road debris, dirt, ice, etc. If any open or chafed wires are present, repair them. Additionally, inspect the connectors involved by disconnecting them and checking for any bent or damaged pins that could cause electrical issues. High resistance within a circuit can cause excessive heat, potentially leading to insulation damage. This would indicate a problem.
NOTE: Always solder and shrink wrap any damaged wires, especially when they are exposed to the elements. Replace connectors with OEM ones to ensure proper electrical connections.
Basic Step #2
Using your service information, locate the actuator. In some cases, the actuator may be externally accessible. If this is the case for your vehicle, you can verify the integrity of the actuator itself. The desired values for this test can vary significantly, so make sure to have a multimeter and service manual on hand. Always use appropriate test pin connectors to avoid unnecessary damage to the connections. If the recorded values are outside of the desired range, the sensor may be deemed defective and should be replaced with a new one.
Basic Step #3
Inspect your ECM (engine control module) and TCM (transmission control module) for any obvious damage. Sometimes, these modules are located in areas where water can become trapped, leading to corrosion. The presence of green powder should be taken as a warning sign. Given the complexities of ECM diagnosis, a licensed technician should handle this step.
This article is strictly for informational purposes only, and the technical data and service bulletins for your specific vehicle should always take precedence.
