Error Code P0815: What It Means & What To Do?

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The OBD code P0815 is set when the Powertrain Control Module or the PCM module recognises an issue with the electrical circuit of the upshift switch circuit of the vehicle. This upshift/downshift switch can be found in the passenger compartment near the vehicles gear shifter. These switches are only found in vehicles which possess a manual transmission only. If you have an automatic transmission system you will not see this code flashing, if at all it does set, then there is a problem with the PCM.

When the PCM observes a voltage or resistance signal coming from your vehicles upshift switch circuit and it is not within the range specified by the manufacturer it will set P0815 code. Upon setting the code the check engine light may also be illuminated, so that you know there’s a problem and that you need to resolve it.

What causes this problem with the Upshift Switch Circuit?

Usually when there is a liquid leak into your vehicles upshift/downshift switch this P0815 code will appear. There could be other causes too, like shorted or open wiring, corrosion of the connectors, damaged or disconnected wiring or connectors related to the shifter

1. Vehicle’s Upshift/Downshift Switch - Look for any damages and see if they can be repaired to get rid of P0815 code. If not, then you will have to go for replacement.
2. Powertrain Control Module - If you have been able to detect a problem with the PCM module, correct it via repairs and see if the P0815 code returns. If it still does you will have to replace it. But don’t worry Parts Avatar has you covered, order online with us and avail free shipping on orders over $99. We ship all across Canada!
3. Vehicle’s Shifter - You may note that the shifter itself is beyond repair and requires replacement. Ensure it is compatible with your vehicle's make, model and also engine.
4. Check Engine Light - Repair or replace it as needed and get rid of P0815 code

If you are facing OBD error code P0815, then there are significant common symptoms that can be felt or observed. We have worked out a list here to help you out in understanding this problem better.

Common Symptoms

• Disabled functioning of the manual shifter
• Transmission enter limp-mode
• Harsh shifting of transmission
• Torque convertor doesn’t lock up as normal
• Check engine light illuminates after few cycles

It is very important to fix the fault code P0815. So here are some ways with which you can correct this issue:

• Repair or replace the PCM
• Repair or replace normal/performance switch of transmission
• Repair or replace damaged wiring, circuits and connectors

To do all this, you will need few high-quality auto parts such as Vehicle’s Upshift/Downshift Switch, Upshift Switch, Powertrain Control Module, Vehicle’s Shifter, Check Engine Light and so on. From where will you get them? From your local store? Well, why go there when you can order quality parts with us while sitting in the comfort of your home. So, just browse through our website and order your needed parts today.

If you want to easily diagnose this fault code, then all you have to do is to follow the steps which are mentioned below:

• Get hold of the tools you will need for diagnosis, a good quality scanner and a digital volt/ohmmeter or DVOM. Connect the scanner to your vehicle's diagnostic port, retrieve all the data and freeze frame it. Also make note of all the codes in their order of occurrence for reference if the code is intermittent.
• Carry out a visual inspection of all the related connectors, wiring and circuits. Any burned shorted wiring will have to be repaired or replaced as per the extent of damage. You may also find corroded, damaged wires, if you see that the system wiring is in very bad condition, and repairs may not resolve the matter, then you will have to replace the full internal transmission harness. If upon inspection you find that the wiring and connectors are in good condition you can proceed to clearing the codes and taking your vehicle for a test drive.
• Wait and see if the PCM enters readiness mode and code doesn’t set, if this happens then you have an intermittent condition. These are rather tricky to diagnose and in some cases the condition has to worsen before there’s clarity on where the issue may be.
• If the code immediately resets, and the transmission is operating correctly, you will have to check voltage and ground signals at the actuator as well as the upshift switch.
• Be careful and first disconnect all the related controllers before performing any tests, this is very important when you are going to start testing for continuity and resistance in the wiring circuits. Refer the diagrams provided by your manufacturer to locate the upshift selector system as well as all the related switches and circuits.
• Compare the results you have found with the ones prescribed by your manufacturer and see if they are in the range. If they’re all fine, then you can suspect a problem with the PCM.

Common mistakes when diagnosing the P0815

• Overlooking spilled liquids in the engine
• Focussing on wiring malfunctions in the transmission
• Replacing PCM before thoroughly checking the upshift/downshift switches

P0816 - Downshift Switch Circuit