Guide To P0794 OBD Error Code Solutions

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You just found out your vehicle has the OBD-II code P0794 stored, well, we are here to help you understand exactly what Intermediate Shaft Speed Sensor A Circuit Intermittent means. First of all, this is a generic code and applies typically to OBD-II vehicles with automatic transmissions. Repairing steps for this code differ from vehicle to vehicle, and mainly depend on the year of make, model and powertrain configuration. This OBD error is set by the Engine Control Module/ ECM and/or the TCM (Transmission Control Module). In your vehicle there is an intermediate shaft aka layshaft, it helps in distributing rotational force between the input drive to the output shaft inside the transmission. The speed of this intermediate shaft is dependent on the gear your vehicle is put in, in a manual transmission car, the driver selects the gear and hence dictates this, so there’s no need for the intermediate shaft to monitor the speed. However, in a automatic transmission vehicle, when you are in “D” drive, the gear you are in is heavily determined by the Transmission Control Module. It does this by using multiple sensor inputs which contribute to the vehicle shifting between gears smoothly and ad per the desire of the driver. One of the important sensors here is the intermediate shaft speed sensor. The TCM needs specific input to help determine and adjust hydraulic pressures, sift points as well as patterns. The P0794 code Intermediate Shaft Speed Sensor A Circuit Intermittent is set when it detects an intermittent or haphazard signal from the A speed sensor or its circuit. You will have to refer your vehicles manual in order to figure out which is the “a” part of the circuit for your specific application.

The job of the intermediate shaft speed sensor is to inform the TCM on what speed the intermediate shaft of the transmission is pining, so that correct gear exchange can happen. When the TCM receives an inaccurate signal, it is unable to properly shift the vehicle from gear to gear, because the vehicle needs to change rates and speed of acceleration. The Powertrain Control Module or the TCM will set P0794 code.

What causes this problem with the Intermediate Shaft Speed Sensor A Circuit Intermittent?

• Defect in the damaged Intermediate shaft speed sensor
• Electrical issues in the wires between the speed sensor and modules
• Internal issue with the ECM and/or TCM
• Other related sensors/solenoids have become damaged or defective like; Input shaft speed sensor, Output shaft sensor, Shift solenoid etc.
• Contaminated or low automatic transmission fluid (ATF)

1. Automatic Transmission Module - In order to get rid of the P0794 code from flashing, you may need to repair certain parts of the transmission, if that doesn’t help resolve the problem, then you will have to go for a replacement.
2. Shaft Speed Sensor - Try to fix the damages or replace if needed and resolve the P0794 code.
3. Automatic Transmission Fluid - Only go for the best quality fluid, your vehicle needs to have superior quality transmission oil. We have the best range of Transmission fluids for you, so don’t delay and pick one up today from our warehouses located across Toronto.
4. Output Shaft Sensor - Repair it if replacement is needed, then go for only good quality sensors.

We at Parts Avatar Canada care for our customers, and that’s why we will help you to diagnose P0794 code by listing out some major symptoms. They are mentioned below as follows

Common Symptoms

• Shifting becomes difficult and hard
• Numerous instrument panel lights light up
• Drivability is poor
• Engine speed starts to fluctuate

Learn the ways with which you can correct this trouble code:

Just like engines in general, the car engine system also employs specially made hydraulic lifters also known as switching roller followers for the intake and exhaust valves for the OBD code P0794. By disengaging an internal locking pin, the lifters can freely be collapsed, this locking pin is disengaged using solenoids to alter oil pressure fed into the liter.

Don’t get tensed if you are still facing any of these issues as we care for our customers and that’s why we offer a good range of Automatic Transmission, Shaft Speed Sensor, Automatic Transmission Fluid, Output Shaft Sensor and a lot more. We are sure that now all your issues would be resolved.

It is essential to diagnose this fault code. Here are some steps which a mechanic should follow for diagnosing the problem that triggered a P0794 code to be stored:

• Start with checking the quality and the quantity of the transmission fluid. Check for any contaminants like dust or debris that may have accumulated, the level of the fluid should also b optimum. If the ATF has burnt smell, then it means that the transmission was running on low fluid and may require a full service with replacement of filter, gasket as well as the fluid. Once you have found the issues with the fluid, simply clean and refill it as needed. If the fluid looks fine, then you will have to locate the intermediate shaft speed sensor. You can take help from your vehicle manual to find the exact location of this, these sensors are typically mounted directly to the transmission housing. If you want to access the sensor from under the hood, you will have to remove a couple of components like the air cleaner and box, wires, miscellaneous brackets etc. just ensure that the sensor and its corresponding connector are all in good condition and connected properly.
• The speed sensor should be taken out and cleaned thoroughly. If you have found excessive dirt in the sensor’s pickup, then you will have to clean it up, it may cost you, but not as much as the damage it potential could cause to your vehicle.
• You can simply use a rag and cleaner to clean the sensor pickup. Any dirt and/shavings that may be present here can change the sensors readings, do don’t take this step lightly. Be diligent and clean it up well. If you are able to notice any signs of rubbing on the pickup then that's indicative of inadequate spacing between present between the reluctor ring and the pickup.
• There are high chances that the sensor malfunctioned and started hitting the ring, so if the replacement sensor still doesn’t clear the rings you will have to refer the manufacturer's instructions to adjust the pickup/reluctor gap.

Common Mistakes When Diagnosing the P0794 Code

• Failure of the Intermediate shaft speed sensor
• Failure of the vehicles Powertrain Control Module (PCM)
• Failure of the Transmission Control Module (TCM)
• Issue with wiring