P0607 is a general OBD2 diagnostic code, meaning it has the same meaning for the Toyota Prius as it does for any other vehicle. It is not a very common code.
The P0607 code is usually caused by a faulty PCM or ECM, the battery, or the wiring to and from the PCM.
P0607 Definition: Control Module – Performance
P0607 has a two-part meaning:
The control module is commonly called the powertrain control module (PCM) or engine control module (ECM). It takes all the data from the different sensors of the Toyota Prius and uses it to control the spark timing, the air-fuel mixture, the idle speed, etc.
Without PCM, a modern vehicle’s engine would not run.
The PCM has detected that it is not working correctly and has issued P0607. Trouble codes are stored in your Prius’ PCM memory. So it has to be working somehow if you can get the code out.
Toyota Prius: P0607 Symptoms
P0607 can have different symptoms depending on the degree of PCM involvement. Are here:
- Won’t Start- This is a common symptom of P0607. If the PCM is not working properly, the engine may not be getting a spark. This can occur while the vehicle is moving on the road.
- Clean Mode – If the PCM has a clean mode protocol, it can activate it to help you get home.
Toyota Prius P0607 Causes + Diagnosis
PCM failure is rare. These on-board computers are designed to last the life of your Prius and rarely fail. But, it can happen.
This section gives you the most common causes of P0607 in order from the easiest to check to the most difficult, ending with the PCM itself.
1. Check for TSB’s
Make sure there is no Technical Service Bulletin related to your Prius’s PCM. TSBs are communications that Toyota uses to cover known problems with a vehicle, as well as how to fix them.
2. Corroded battery terminals
The PCM in your Prius requires a constant level of battery voltage. If the posts are corroded by battery acid (or if they are not properly tightened), the voltage to the PCM can fluctuate. This causes you to not be able to consistently read everything the engine does (or not work at all).
If the battery posts are corroded, your local auto parts store sells a battery post cleaner that goes directly onto the battery posts and posts. A piece of sandpaper or a wire brush will work well if you’re in a pinch.
3. Defective battery
If the battery has gone bad, it can sometimes affect the operation of the PCM. Almost any place that sells batteries can check this for you.
If the battery light comes on while driving, it is likely related to P0607. The battery light may mean the battery is bad. It can also mean that there is a bad alternator. It would be best to start by checking the battery, as it is easier to check than the alternator.
Even if there is no battery light, the battery may be the cause of P0607.
4. Loose dirt in the PCM
If the battery appears fine and tests OK, check the ground cable going to the PCM. You will need to find the engine pinout for your specific Prius model and find the ground pin and trace it to where it is connected to the chassis.
Once you find it, confirm that the cable is not damaged in any way. Make sure it is securely bolted to the chassis. If there appears to be rust or corrosion, unscrew it and clean the contact surfaces with sandpaper.
5. PCM power circuit
The power cable going to the PCM may have been damaged or shorted. Follow the wire from the fuse panel to the PCM. Make sure it is not damaged. Look for cut, melted or damaged cables.
The PCM may need to be replaced or a reflash done. Again, make sure there is no TSB for your Prius model
There are many things you can check yourself when diagnosing P0607 on the Toyota Prius, but if you don’t find anything wrong, take it to someone who has experience with these things before purchasing a new PCM. Good luck!