Technical Description of OBD-II Trouble Code
The Actuator Supply Voltage B Circuit is registering a low voltage
What does that signify?
This is a generic diagnostic trouble code (DTC) that applies to OBD-II vehicles. It can be found in various vehicle makes such as Dodge, Chrysler, Ford, Chevrolet, Toyota, Honda, Nissan, etc.
The Engine Control Module (ECM) is responsible for monitoring and adjusting sensors, solenoids, actuators, valves, etc. It ensures that all these components are working together seamlessly to achieve optimal vehicle performance and fuel efficiency. If you receive a P2670 or a related code, depending on your vehicle make and model, you may experience transmission drivability issues.
It’s worth noting that in my experience with European models, I have also encountered this code as an EVAP diagnostic code. Therefore, it is important to consult your service manual for accurate diagnostic guidance. Often, your symptoms will provide clues about the systems/components you need to address to resolve the issue.
Regarding the P2670 and related codes, the ECM detects an abnormal value in the actuator supply voltage circuit. It compares the actual values to the desired ones and if they deviate beyond the desired range, it triggers the Malfunction Indicator Lamp (MIL) on your instrument panel. The ECM must monitor this fault over multiple drive cycles before illuminating the MIL. It is crucial to research the designation for “B” within the circuit, as it may refer to a specific wire, harness, or location depending on your vehicle make and model. Always refer to the OEM technical service information for accurate guidance.
Depending on the specific description for this code in your vehicle make and model, it may also be detected by the Transmission Control Module (TCM).
P2670 (Actuator Supply Voltage B Circuit Low) is active when the ECM or TCM detects a low voltage situation in the actuator supply voltage “B” circuit.
What is the severity of this DTC?
Generally speaking, the severity of this DTC is moderate. However, since there are multiple code descriptions, caution should be exercised during diagnosis. Proper service data is essential. If this code pertains to the transmission in your case, it is advisable to address the issue promptly. 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 associated with a P2670 diagnostic code may include:
What are some of the common causes of the code?
Possible causes for this P2670 trouble code may include:
What are some P2670 diagnostic and troubleshooting steps?
The initial step in the troubleshooting process for any malfunction is to consult the Technical Service Bulletins (TSB) for known issues specific to your vehicle.
Advanced diagnostic steps are highly vehicle-specific and may require specialized equipment and knowledge for accurate execution. The following are basic steps, but it is recommended to refer to a vehicle year/make/model/powertrain specific repair guide for precise instructions pertaining to your vehicle.
Basic Step #1
The approach to diagnosing this code will depend on your vehicle make and model, as well as the symptoms you are experiencing. However, as a general practice, it is advisable to clear the codes with a 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 exposed to road debris, dirt, ice, etc., which can cause damage. If any open or chafed wires are present, repair them. Additionally, inspect the connectors involved by disconnecting them and examining the pins for any bent or damaged ones that could cause electrical issues. Sometimes, high resistance within a circuit can generate excessive heat, leading to insulation damage. This would indicate that you have found the 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
Refer to your service information to 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 deviate from the desired range, the sensor can be considered defective and should be replaced with a new one.
Basic Step #3
Inspect your Engine Control Module (ECM) and Transmission Control Module (TCM) for any visible damage. Sometimes, they are located in areas prone to water accumulation, which can lead to corrosion. The presence of green powder should be regarded as a warning sign. Given the complexities of ECM diagnosis, it is recommended to consult a licensed technician at this point.
This article is intended solely for informational purposes, and the technical data and service bulletins specific to your vehicle should always take precedence.
