P0768 code definition
When the PCM in your vehicle records trouble code P0768, it means that it has found a problem in shift solenoid D.
What the P0768 code means
Your vehicle’s automatic transmission makes use of shift solenoids to transfer fluid through the hydraulic circuits and change your gear ratios. You need varying gear ratios to accelerate and decelerate, and also to ensure that your engine is working properly and you are getting good fuel economy. If the gear ratio recommended by your vehicle manufacturer is not compatible with the actual ratio that the PCM detects, then a P0768 code is stored, and your Check Engine Light may come on.
What causes the P0768 code?
The most common causes are: * A bad shift solenoid * Transmission problems * Low or dirty transmission fluid * A bad TCM (transmission control module)
What are the symptoms of the P0768 code?
You might drive for a very long time without seeing any symptoms other than a glowing Check Engine Light, but it might be best not to count on that. You could also experience the following:
- Slipping in the transmission
- An overheating transmission
- Rough shifting
- Poor fuel economy
- Vehicle entering “limp in” mode
How does a mechanic diagnose the P0768 code?
The first step in diagnosing the P0768 code is for the mechanic to use a code reader and an ohmmeter to evaluate the computerized system in the vehicle that regulates speed inputs and transmission outputs.
Next, the mechanic will:
- Examine the transmission fluid to see if it is dirty or low, or if it has a burnt smell
- Flush out the transmission fluid if it is determined to be contaminated
- Examine wiring and connectors and replace any that are damaged
- Check the hydraulic pump, pressure regulator and solenoids and replace any defective parts
- Re-test the system to make sure that any repairs have been successful
- Test drive the vehicle, and upon returning re-check to determine if the codes have cleared
- Do a voltage check if the codes have re-appeared
- Repair or replace any connectors and circuits that have been identified as faulty following the voltage check
- Do another re-test
Common mistakes when diagnosing the P0768 code
Mechanics sometimes assume that the shift solenoid is faulty and replace it when in fact, the problem is nothing more than contaminated transmission fluid. Sometimes, too, they may replace the PCM, assuming that it is not working properly, but the fact is that your vehicle’s PCM is hardly ever likely to fail.
How serious is the P0768 code?
Difficulty shifting can be problematic, especially if you are driving at highway speeds. If you are just driving around town, failing to get into proper gear is not likely to get you killed. On the Interstate, though, it can be a very different matter. So, think about your driving habits, and if you are driving in areas where you may need to accelerate or decelerate quickly, get this issue dealt with right away.
What repairs can fix the P0768 code?
You might not even need a repair – it’s possible that just topping up your transmission fluid could correct the problem. You might need repairs to wiring and connectors, though, or a new shift solenoid, or very rarely, repairs to your PCM.
Additional comments for consideration regarding the P0768 code
Even if your shifting issues are not causing you huge problems, it is best to get them corrected. Otherwise, you could end up with costly transmission repairs later on.
Need help with a P0768 code?
Transmission issues are no problem for YourMechanic. Contact us at 1-800-701-6230, or arrange an appointment using our online form. We will dispatch a qualified mobile mechanic to your home or office to repair your vehicle at your convenience. You can rely on us to be there for you whenever you need vehicle maintenance or repairs.