Error Code P0907 is defined as Transmission Gate Select Position Circuit High. This is a generic trouble code, meaning it applies to all vehicles equipped with the OBD-II system, especially those made since 1996 up to the present. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.

When this code appears, it means there’s a problem with the vehicle’s transmission gate. This component is an analog switch designed to selectively block or pass signal level from the input to the output. It is made up of nMOS and pMOS transistor.

The transition gate works by assisting the vehicle in shifting gears. When this code appears, that means the circuitry that helps it function (send feedback to the PCM) is running high.

For most vehicles, the Check Engine light will be activated when this code is stored. However, in some cases, it may take multiple incidents before the light is activated. There are also some cases where the Check Engine light is not activated at all.

This code may be accompanied by related GSP sensor codes, such as:

  • Error Code P0904
  • Error Code P0905
  • Error Code P0906
  • Error Code P0908
  • Error Code P0909

Common Symptoms

  • Difficulty driving
  • Ignition struggles to respond when accelerating
  • Ignition idles out when running at low RPM

Possible Causes

Wiring problem is the most common cause of this code, i.e. damaged, disconnected, frayed, etc. Sometimes, it could be caused by a faulty PCM, though this is very rare.

How to Check

Start by connecting an OBD-II scanner to the vehicle and retrieve the stored codes. As said earlier, there are a number of other codes that may be associated with this one, so don’t be surprised if you see multiple codes. This will also give you an idea of where to start the diagnosis.

The most common cause, as said earlier, is a problem with the electrical components. Thus, continue the diagnosis by inspecting the electrical system of the said component. Look for any signs of damage.

You may need to check the PCM too.

After repairing or replacing any damage or fault in the electrical wiring system, or addressing the PCM, take the vehicle for a test drive to see if the code comes back.

In rare conditions, you may need to check the fuses too.

How to Fix

  • Repair or replacement of damaged connectors and wires
  • Replacement of blown fuses
  • Replacement of PCM (extremely rare)

Anytime the ignition isn’t performing as it should, you will have to make the repair a priority, or the problem may get worse and expensive.

When addressing this code, the most common misdiagnosis is simply stopping the repair once the frayed wire or loose connector is found. Thus, it is best to use the OBD-II scanner to check every possibility behind the problem thoroughly.