P0792 code definition
The P0792 code indicates that the PCM detected an incorrect input signal from the transmission intermediate shaft speed sensor circuit. In many cases, this code will be accompanied by input speed sensor codes as well.
What the P0792 code means
The PCM uses information from the transmission intermediate shaft speed sensor to assist in proper shifting. As the shaft speed gradually increases, the PCM will monitor the shifting operation until the shift point occurs. If the shaft speed is not increasing, or if the signal received from the intermediate shaft speed sensor is erratic or not within the proper range according to the manufacturer’s specifications, the PCM will store the P0792 code.
What causes the P0792 code?
Most commonly, the P0792 code is caused due to a defective intermediate shaft speed sensor. The output speed sensor or the input speed sensor may also be at fault. Other causes include:
- Damaged electrical components, such as wiring or connectors
- Faulty shift solenoids
- Dirty or contaminated transmission fluid blocking the fluid passages
- Defective engine drivability sensors
- Defective engine temperature sensor
- Defective valve body
- Faulty PCM, in very rare cases
What are the symptoms of the P0792 code?
In addition to the illuminated Check Engine light, the P0792 code may be accompanied by symptoms such as:
- Harsh shifting
- Decreased fuel efficiency
- Failing speedometer
- Stalling engine
- Misfiring engine
- Hesitating engine
How does a mechanic diagnose the P0792 code?
Diagnosing the underlying issue that causes the P0792 code should begin with an inspection of all electrical components. After repairing any loose, damaged, corroded, open, shorted, or otherwise malfunctioning electrical wiring or connectors, the mechanic should clear the code and retest the system. If the code returns, the mechanic should begin checking the transmission fluid to be sure it isn’t dirty or contaminated. If the transmission fluid smells burnt, the entire system may need to be flushed and cleaned, and refilled with clean fluid.
After these two attempts to diagnose the issue, the mechanic should continue testing components and comparing the voltage readings to manufacturer specifications until the correct component is found. After any repair is attempted, the mechanic should clear the code and retest the system to ensure that the issue was fully diagnosed and repaired.
Common mistakes when diagnosing the P0792 code
There are many common misdiagnoses when the P0792 code is present. Speed malfunctions, fuel delivery problems, transmission problems, or driveline malfunctions, are often incorrectly blamed. Vehicle speed sensors are frequently replaced unnecessarily.
How serious is the P0792 code?
If the P0792 code is being detected, a vehicle should be repaired immediately. This code indicates a serious issue within the transmission; left alone, it may result in massive transmission failure, or unsafe driving conditions.
What repairs can fix the P0792 code?
There are many ways that a technician can address a P0792 code detection. They include:
- Replace a defective intermediate shaft speed sensor. Replace the output speed sensor or the input speed.
- Replace damaged electrical components, such as wiring or connectors.
- Replace faulty shift solenoids.
- Replace dirty or contaminated transmission fluid with clean fluid.
- Replace defective engine drivability sensors.
- Replace defective engine temperature sensor.
- Replace defective valve body.
- Replace faulty PCM, in very rare cases.
Need help with a P0792 code?
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