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Error Code P075F Transmission Fluid Level Too High. This is a generic trouble code, meaning it applies to all vehicles with the OBD-II system, especially those made since 1996 up to present and equipped with automatic transmission. This includes vehicles from, but not limited to, Chrysler, Dodge, Ford, Hyundai, Ram, Kia, Toyota, Lexus, Mazda, Honda, Volkswagen, etc. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model and powertrain configuration.
If this code is present, that means the vehicle comes with a Transmission Fluid Level (TFL) sensor. The purpose of this sensor is to determine the level of the transmission fluid in the transmission. An incorrect transmission level can cause performance problems and serious damage.
The TFL sensor receives a signal voltage from the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes). The PCM then monitors the circuit, if it determines a level that is too high and out of range, then it activates the check engine light or transmission warning light and registers the Error Code P075F.
The Error Code P075F is set when the transmission fluid level is too high from the required level. Other related codes include:
- Error Code P070A
- Error Code P070B
- Error Code P070C
- Error Code P070D
- Error Code P070E
- Illumination of the Check Engine light
- Illumination of Transmission warning light
- Problems on transmission performance
The most common cause of this code is a high transmission level. Other possible causes include:
- Defective transmission fluid sensor
- Faulty electrical or wirings
- Faulty PCM
How to Check
The transmission fluid level must be in accordance with the recommendations of the vehicle’s manufacturer. Thus, it should be the first thing you need to check when diagnosing this code.
Next, check the transmission fluid level sensor and its corresponding wires. Damaged and loose connections to this sensor can cause the code. Repair any damages found, clear the code and see if it returns.
Next is to consult with the Technical Service Bulletins (TSBs). If you don’t find anything about the problem, then you have to move forward with the diagnosis.
Here is a generalized diagnostic procedure for the error code. To get the most accurate diagnosis, consult your manufacturer’s diagnostic flow chart.
Check the wiring
Before proceeding with the diagnosis, consult the factory wiring diagram to determine which wires are connected to which. There are many free online repair manuals you can find for most vehicles. Some are available via subscriptions.
Check the reference voltage circuit side
Switch on the ignition and use a digital multimeter set at DC volts to inspect the reference voltage. This should be at 5 or 12 volts from the PCM. Get this by connecting the positive meter lead to the sensor B+ terminal on the connector’s harness side and the negative meter lead to the ground. If there are no reference signal present, then switch off the ignition, set the multimeter to ohms and connect it to the reference voltage pin on the TFL and the reference voltage pin of the PCM. If the meter shows Out of Limits (OL), that means there is an open circuit problem between the PCM and the sensor. Locate this problem and repair immediately. If the meter shows numeric value, then there is continuity.
If you see no problems up to this point of the diagnosis, then if there’s a power from the PCM coming out. Turn the ignition on and set the meter to DC volts. Then, connect the positive end of the meter to the reference voltage terminal on the PCM. Again, the negative lead must be connected to the ground as well. If you find no reference voltage present in the PCM, then you must have a faulty PCM. However, you should remember that PCMs rarely go bad. It’s best to double-check your diagnosis.
Check the ground circuit side
Set the digital multimeter at ohms and use it for continuity check. Make sure the ignition is turned off. Then, connect the meter between the transmission fluid level sensor ground terminal and the chassis ground. If the meter shows a numeric value, then there is continuity. If the meter shows OL, then there must be an open circuit problem between the PCM and the sensor. Locate the problem and repair.
Check the sensor itself
If everything checks out good up to this point of the diagnosis, then the probability is at the sensor. Check by turning off the ignition and set the multimeter at ohms. Take out the transmission fluid level sensor connector, then connect the meter to the terminals of the sensor. If the meter shows OL readings, then there is an open issue inside and must be replaced.
How to Fix
The common fixes for this error code are:
- Replacement of faulty transmission fluid sensor
- Repair or replacement of faulty electrical wirings and connectors
- Replacement of PCM
The severity of this code ranges from moderate to severe. In many cases, when left attended, a high transmission level can damage the transmission, which can be a pretty expensive fix. It’s best always to address this code as soon as it comes up.