The P0746 OBD II is a diagnostic trouble code that is associated with the performance of the pressure control solenoid circuit. It can happen due to various reasons. It is taken as a generic code which means that it will apply to all the vehicles having an OBD II system.
What exactly P0746 OBD II Code means?
The P0746 code appears when there is some issue in the fluid pressure. Most of the time fluid pressure will not match the actual value that PCM measures. Pressure control solenoid contains springs and it is used by the vehicle for the transmission fluid flow. The transmission fluid flow is used for the changing gear system. The code shows that the computer is not able to control the torque converter.
In vehicles having automatic transmission torque converter lockup, as well as shift functions, are controlled through the pressure. You have heard so many times about the cars having hydraulic brakes. Although the exact pressure that is used to make that functions work varies from vehicle to vehicle. So the exact amount can never be explained because one vehicle will be having more or less as compared to the other. The factors that affect these are vehicle speed, the load of the engine, engine speed, etc.
The real causes of the P0746 OBD II code
Many causes result in P0746 OBD II which are the following:
- The transmission fluid is really dirty
- The transmission filter got clogged
- The hydraulic passage is not clear
- The fluid level of the transmission is very low
- The wiring is broken
- The transmission pump is damaged
- The valve body defects
- The ECU failed
- pressure control solenoid defects
Symptoms of P0746 OBD II code
The code P0746 shows many symptoms which are the following:
- Check Engine Light: The check engine light gets on.
- Fuel Consumption: The fuel consumption of the vehicle increases drastically.
- Misfire: You will experience the misfire-like signs in the car.
- Transmission issues: The transmission starts to overheat.
- Engine: The engine starts to stall.
- Gear issues: The vehicle starts to get stuck in the gearing system. You will also feel slipping in the gear system.
Steps to Diagnose and fix Code P0746 OBD II
Common Code P0746 OBD II Diagnosis Mistakes: The most common mistake that mechanics make while dealing with code P0746 is that they focus on the transmission pump just. Not in all cases, you can blame the transmission pump for the issue as wiring and other components can also cause it. So do not change the pump blindly without ensuring the issue.
Tools to fix P0746 Code
- Obd2 Scanner
- Digital Multimeter
How to start diagnoses Tools to fix P0746 Code OBD II
Many parts are involved in the trouble when code P0746 flashes but they can be fixed. It would be better if you get more information about the vehicle model and specification to better deal with the issues. Here are the steps you can follow:
- Scanning: The first step is to grab the scanner and start scanning the vehicle. Check whether the P0746 code is the only one showing or if there is the possibility of any other code as well.
- Visual inspection: In the case of every error the visual inspection is the step that can sort out many issues. Examine the vehicle properly to find out all the problem areas.
- Dirty Fluid: Check the fluid level and see if it looks like it’s burnt. It changes the color which indicates that the fluid got defected. Also, look for the consistency of the fluid. The fluid needs to be changed if you see any of the above defects.
- Wiring: If all parts and fluid are working fine then the problem might be due to broken wiring. Check all the wiring connecting various parts and identify the one causing the issue. Repairing the target wiring will help to solve the P0746 code.
- Connectors: Make sure that all the connectors and their connections are working properly. If you see any defects in this area then repair them immediately.
- Transmission Pump: Sometimes the transmission is electronically driven and sometimes it will be mechanically driven as it depends upon the specification of the vehicle. If the transmissions pump show any defects then consider changing it.
- Advance measures: The advanced measures depend upon the model and specifications of the vehicle. You need to grab the manual to get more information about your vehicle if you are thinking to deal it with yourself. Otherwise a professional already knows about the main steps. The continuity check can be performed to find the defective wires. The normal value will be 0 for connections and wiring otherwise it is broken.
Replace/Repair These Parts to Fix OBD Code P0746 OBD II
The code P0746 can be dealt with by replacing the following:
- Fluid and Filter: The fluid and filter can be a common cause of code P0746 issue so change these.
- Transmission Pump: The problem can also occur due to a faulty transmission pump so check whether it needs to change or not. If the transmission pump seems damaged then replace it.
- Pressure Control Solenoid: The pressure control solenoid can also be the trouble maker so change it if it is faulty.
- Wiring: So many times all the parts work fine except the wiring that is broken. It makes things hard to handle.
- Passage Cleaning: Check whether the transmission flush passage needs cleaning.
- Connectors: Review the condition of the connectors in case they need to be cleaned or changed.
- Replace PCM: If all the remaining components are working fine then PCM is the root cause of the issue and it should be replaced.
The severity of P0746 code OBD II
The P0746 code can be considered very dangerous. As in this problem, the computer loses control over the transmission resulting in the slipping of the vehicle. The vehicle can also stall anywhere or overheat due to this code.
Other Codes related to P0746 code OBD II
The other codes that are related to P0746 are P0745, P0747, P0748, and P0749 as they all represent pressure control solenoid circuit issues.