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P2670 OBD-II Trouble Code: Actuator Supply Voltage B Circuit Low

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P2670 code definition

A P2670 trouble code indicates the detection of a problem by the PCM or a supporting control module in the actuator supply voltage B circuit. Some of the possible modules that could detect this fault include the alternate fuel control module, the anti-theft module, the antilock brake control module, the body control module, the climate control module, the cruise control module, the fuel injection control module, the instrument panel control module, the proximity alert module, the traction control module, and the turbo control module.

What the P2670 code means

A P2670 trouble code means that the actuator supply voltage B has suffered a malfunction. While a trouble code could be stored, the Check Engine light might not initially illuminate on some models of cars, requiring up to eight drive cycles with an actuator supply voltage B failure before illuminating. In some cases, though, depending on vehicle make and model, the Check Engine light can illuminate on the first such failure.

What causes the P2670 code?

A P2670 trouble code is commonly caused by an internal malfunction within the PCM itself, shorted wiring or connectors between interfacing control modules, loose or disconnected ground wires to various control modules, including the PCM, and shorted wiring and connectors in the circuitry of the PCM input from the vehicle engine.

What are the symptoms of the P2670 code?

In addition to a stored trouble code, the symptoms of a P2670 trouble code include:

  • A no-start or hard-to-start condition
  • Engine misfires and rough running
  • Lower fuel efficiency
  • A lack of engine power

Keep in mind that even though the Check Engine light has not illuminated, the PCM could still have the P2670 trouble code showing as pending.

How does a mechanic diagnose the P2670 code?

In order to successfully diagnose, repair, and clear a P2670 trouble code, a mechanic must do the following:

  • Follow the manufacturer's recommended method for testing, diagnose each individual control module, replacing them as necessary if a problem is detected.

  • Keep in mind that replacing a control module requires the modules' reprogramming on the mechanic's part.

  • To properly diagnose a P2670 trouble code, a mechanic needs an advanced scanner, or code reader, and a digital volt/ohmmeter.

  • In addition, a mechanic needs a manufacturer's wiring schematic to successfully diagnose a P2670 code. The wire schematic allows the mechanic to perform a careful inspection visually of wiring connecting the PCM to individual control modules.

  • After replacing all faulty modules and wiring, the mechanic needs to clear the error codes.

  • Also, test drive the vehicle while the advanced scanner is connected to the PCM to see if the code returns after clearing.

Common mistakes when diagnosing the P2670 code

A common misdiagnosis of a P2670 trouble code is assuming symptoms and stored codes that represent a communication failure are the cause of the problem. Of course, fixing and clearing these type of codes do little to fix the actual problem and result in the trouble code returning.

How serious is the P2670 code?

A P2670 trouble code, if left unattended, can lead to trouble starting the vehicle, lower overall power, and reduced fuel mileage. In addition, a P2670 trouble code can cause the engine to misfire and operate roughly.

What repairs can fix the P2670 code?

The best way to fix and clear a P2670 trouble code is to replace any faulty wiring and connectors, as well as any malfunctioning control modules. If the fault lies within the PCM itself, the mechanic needs to replace that as well. In addition to replacing any faulty or worn wiring, connectors, or components, when performing a repair, the mechanic also needs to perform the following:

  • Test the control module ground circuits for continuity with the ground on the battery.

  • Upon retesting, if the P2670 trouble code returns, inspect all of the components again to further diagnose the problem. This includes inspecting the wiring, connectors, PCM, and other individual control modules.

  • You should also install a memory saving device to prevent the PCM and control modules from losing their memory, requiring the mechanic to reprogram them.

  • As a final check, inspect the engine compartment to make sure that all engine and transmission ground cables, straps, and wires have been properly reconnected.

Additional comments for consideration regarding the P2670 code

Keep in mind that testing the wiring, PCM connectors, and individual modules represents a long and arduous process. For best results, utilize a specialized scanner, such as from Autohex or Tech2, to help speed up the diagnostic process. Also, be careful not to misplace the probe while getting a reading, as a misplaced probe can destroy the control modules and require reprogramming of the entire vehicle's systems.

Need help with a P2670 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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