What Does P0793 Mean?
The TCM is receiving no signal at all from the intermediate shaft speed sensor A. This sensor is essential for monitoring internal gear ratios and shift timing. A complete loss of signal typically indicates a hard failure — either the sensor is dead, the wiring is completely open, or the connector has fully separated. The transmission will likely enter limp mode or fail to shift properly.
Safety Warning
The transmission will likely be in limp mode with limited gear availability. Driving should be limited to reaching a repair facility at low speeds. No signal means the TCM cannot monitor gear engagement, risking improper shifts that could cause loss of drive or sudden deceleration.
Common Causes
35%
Failed intermediate shaft speed sensor A (open circuit internally)
30%
Open circuit in sensor wiring (broken wire or disconnected connector)
15%
Damaged or sheared reluctor ring providing no magnetic trigger
12%
Sensor displaced or fallen out of mounting position
8%
TCM input pin failure or internal circuit damage
Diagnostic Steps
1
Confirm zero signal by monitoring the intermediate shaft speed sensor A PID during driving — it should show speed in gear but reads zero.
2
Verify the sensor connector is fully seated and not disconnected or pushed out of the transmission case.
3
Measure continuity from the sensor connector to the TCM connector to rule out open wiring.
4
Check sensor resistance — an infinite reading confirms internal open circuit; replace the sensor.
5
If the sensor and wiring are intact, verify the reluctor ring is present and undamaged (may require pan removal).
6
If all external checks pass, test the TCM input circuit by applying a simulated sensor signal.
Estimated Repair Cost
$150 - $700
Parts + labor, varies by vehicle and location
The TCM is receiving no signal at all from the intermediate shaft speed sensor A. This sensor is essential for monitoring internal gear ratios and shift timing. A complete loss of signal typically indicates a hard failure — either the sensor is dead, the wiring is completely open, or the connector h...
The most common cause of P0793 (Intermediate Shaft Speed Sensor A Circuit No Signal) is: Failed intermediate shaft speed sensor A (open circuit internally)
Typical repair costs for P0793 range from $150 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The transmission will likely be in limp mode with limited gear availability. Driving should be limited to reaching a repair facility at low speeds. No signal means the TCM cannot monitor gear engagement, risking improper shifts that could cause loss of drive or sudden deceleration.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0793 to identify the root cause.
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Quick Info
Category
Powertrain
System
Automatic Transmission
Difficulty
Type
Generic (SAE)
Recommended Tools
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