How severe is this DTC?
The severity here is generally moderate. Since there are multiple code descriptions, you should be cautious when diagnosing. Appropriate service data will be necessary. If this happens to be a transmission code in your case, you certainly want to repair it as soon as possible. Daily use of a vehicle with an active transmission code is a risk we do not want to take.
What are some of the symptoms of the code?
Symptoms of a P2686 diagnostic code may include:
- Poor shifting
- Lack of torque
- Stuck in gear
- Check Engine Light (CEL) on
- Overall poor driving
- Limited output power
- Poor fuel consumption
- Abnormal engine speed/RPM
What are some common causes of the code?
Causes
of this P2686 fault code may include:
- Water intrusion
- Melted/broken connector(s)
- Short to power
- General electrical issue (e.g., charging system problem, bad battery, etc.)
What are the diagnostic and troubleshooting steps for P2686?
The first step in the troubleshooting process for any malfunction is to check Technical Service Bulletins (TSBs) for known issues with the specific vehicle.
Advanced diagnostic steps become very vehicle-specific and may require the appropriate advanced equipment and knowledge to operate accurately. We include the basic steps below but refer to a repair guide specific to the year/make/model/drivetrain for steps tailored to your vehicle.
Basic Step #1
How you approach your diagnosis will depend on your make and model and the symptoms you are experiencing. But generally, the first thing to do is clear the codes with your scanner and drive the vehicle until it becomes active again. If it does, after locating the correct circuit/harness we are working with, inspect it for any damage. It might be routed under the vehicle where road debris, dirt, ice, etc., can damage the circuits below. Repair any open and/or chafed wires, if present. Additionally, it would be a good idea to inspect the involved connectors. You can disconnect them to inspect the pins for any bent or damaged pins that could cause electrical issues. Sometimes, high resistance in a circuit can cause excessive heat. To the point that it can burn through the insulation! That would be a good sign that you have found your problem.
NOTE: Always solder and wrap damaged wires. Especially when they are exposed to the elements. Replace connectors with OEM ones to ensure proper electrical connections.
Basic Step #2
Locate your actuator using your service information. Sometimes these can be accessed from the outside. If that is the case for you, you can check the integrity of the actuator itself. The desired values involved in this test vary widely, but make sure to have your multimeter and service manual on hand. Always use proper test pin connectors to avoid unnecessary damage to connections. If the recorded values are outside the desired range, the sensor may be considered faulty and should be replaced with a new one.
Basic Step #3
Take a look at your ECM (Engine Control Module) and TCM (Transmission Control Module) for any obvious damage. Sometimes they are located in a spot that can trap water and cause corrosion. Any green powder present should be considered a red flag. A licensed technician should take it from here given the complexity of ECM diagnosis.
This article is strictly for informational purposes only, and technical data and service bulletins for your specific vehicle should always take precedence.
