Can this code be set by a good sensor?

Yes, and it happens often enough that it should be your first consideration rather than an afterthought. The controller does not measure the sensor's health — it compares the speed the sensor reports against the speed the commanded gear ratio says it should be. If a clutch pack is slipping, the intermediate shaft really is turning at the wrong speed, the sensor reports that accurately, and the comparison fails. The controller has no way to tell whether the sensor or the transmission is at fault, so it flags the circuit. This is why so many people replace the sensor, drive a few miles, and see the code return with the money gone.

How do I tell a bad sensor from a slipping transmission?

Graph all three shaft speeds together on a road test, which is possible here because this transmission has three sensors rather than the usual two. In each gear the three are locked into a fixed relationship, so if two of them agree with each other and the third does not fit, that third sensor is the liar. If instead the pattern across all three is consistent with an element failing to hold — the intermediate shaft running fast relative to both its neighbours during and after a particular shift — the sensor is telling the truth and the transmission is slipping. The two cases look completely different on a graph and almost identical on a code reader.

What does the debris on the sensor tip actually do?

A speed sensor works by detecting teeth passing close to its tip, and the strength of that detection depends on the gap between the two. Normal transmission wear puts fine ferrous particles into the fluid, and those particles are attracted to a magnetic sensor tip and build up as a fuzzy layer. That layer effectively increases the gap between the tip and the teeth, so the signal gets weaker and less crisply defined. Nothing breaks — the circuit tests perfectly, resistance is fine, there is no open or short — but the reported speed becomes unreliable. It is worth pulling the sensor and looking at the tip before doing anything more elaborate, because cleaning it costs nothing.

I fitted a new sensor and the reading is still wrong. What now?

Check the part number against the one specified for that exact transmission, then check the reluctor and the seating. A sensor that is close but not correct will read proportionally wrong at every speed while passing every electrical test, and that pattern — consistently off by the same percentage across the whole range rather than off only in some gears — is the giveaway. If the part is correct and properly seated, look at the reluctor teeth for damage and then move on to the possibility that the transmission itself is slipping and the sensor has been reporting the truth all along.

OBD-II trouble code

P0792: Intermediate Shaft Speed Sensor "A" Circuit Range/Performance

The intermediate shaft sensor is reporting a speed the controller does not believe. Before replacing it, consider the possibility that trips people up on every ratio-derived code: the sensor may be telling the exact truth about a transmission that is slipping.

High severityPowertrainTransmission / Speed SensorDrivable short-term

Quick facts

System: Powertrain
Category: Transmission / Speed Sensor
Severity: High severity
Drivable: Usually safe to drive short-term
Repair cost range: $150 – $3,500
DIY difficulty: Intermediate DIY

What does P0792 mean?

This code is not generated by measuring the sensor. It is generated by arithmetic. The controller knows what gear it commanded, it knows the fixed ratios that tie the input, intermediate and output shafts together in that gear, and it therefore knows what the intermediate shaft must be turning at. When the reported figure and the calculated figure disagree by more than the allowed margin, P0792 sets. The signal is present and it is electrically healthy — that is what separates this from the no signal and circuit codes. What it is not is consistent with the rest of the transmission.

That mechanism has a consequence people repeatedly get wrong, and it is the most important thing on this page. A ratio comparison cannot distinguish between a sensor reporting the wrong number and a sensor reporting the right number about a transmission behaving wrongly. If a clutch pack is slipping, the intermediate shaft genuinely is turning at a speed that does not match the commanded gear. The sensor sees that correctly and reports it faithfully, and the controller — which has no way to know whether to distrust the sensor or the transmission — flags the sensor's circuit. Replacing a perfectly good sensor is the standard outcome, followed by the code returning within a few miles. On any range and performance code derived from a ratio, mechanical slip has to be excluded before the sensor is condemned, and on this one it is easier to exclude than usual because the transmission has three speed sensors and a slipping element shows up as a specific pattern across all three rather than as one odd reading.

When the fault genuinely is the sensor, the causes cluster around things that corrupt a signal rather than break it. Speed sensors read teeth passing a tip, and anything that changes the magnetic relationship between the two changes the reported speed. Fine ferrous debris — normal wear product suspended in the fluid — collects on a magnetic tip and builds a fuzzy layer that effectively widens the air gap and weakens the signal. A tooth chipped or a reluctor ring cracked produces a periodic error that averages out at some speeds and not others. A sensor not seated fully, or fitted with an incorrect spacer after previous work, sits too far out. None of these break the circuit, which is why the electrical tests come back clean and the code stays.

One useful piece of context for interpreting the reading: an error that scales with speed and an error that stays constant point in different directions. A signal that reads proportionally wrong at every speed suggests a wrong or mismatched sensor or reluctor, which is a parts problem. A signal that only becomes implausible in particular gears suggests something specific to the elements applied in those gears, which is a transmission problem. Noting which of the two you have before touching anything shortens this diagnosis considerably.

Common causes

Slipping clutch pack or band, where the sensor is accurately reporting a transmission that is genuinely not holding the commanded ratio
Ferrous debris built up on the sensor tip, weakening and distorting the signal
Damaged, chipped or cracked reluctor ring producing a periodic error
Sensor not fully seated, or air gap incorrect after previous work
Wrong sensor fitted, with output characteristics that do not match what the controller expects
Low or degraded transmission fluid causing genuine slip that then reads as a sensor fault
Signal wire picking up electrical noise from an adjacent harness or an aftermarket installation
High resistance in the signal path attenuating the sensor's output
Adaptive shift values left unreset after previous transmission work, producing ratios outside the expected window

Symptoms

Check engine light with P0792 stored
Harsh, flared or unpredictable shifts
Engine speed rising briefly during a change before the gear takes hold, which suggests genuine slip
Transmission entering limp mode and holding a fixed gear
Intermediate shaft speed on a scan tool that does not track the other two shafts sensibly
Torque converter lockup engaging and releasing at odd moments
Symptom confined to particular gears rather than present in all of them
Transmission fluid dark or smelling burnt where slip is the underlying cause

Diagnostic steps

1.Take the possibility of genuine slip seriously before condemning the sensor. This code compares a measurement against a calculation, and a sensor accurately reporting a slipping transmission produces exactly the same result as a faulty sensor.
2.Graph input, intermediate and output shaft speeds together across every gear. A slipping element shows a characteristic pattern across all three; a faulty sensor shows one value that disagrees with the two that agree with each other.
3.Note whether the error scales with speed or appears only in certain gears. A proportional error across the whole range points at a mismatched sensor or reluctor. A gear-specific error points at the elements applied in those gears.
4.Check fluid level and condition. Low or degraded fluid causes real slip, which is one of the ways this code gets set by a healthy sensor.
5.Remove and inspect the sensor tip for a build-up of fine ferrous debris. It is normal wear product, it accumulates on magnetic tips, and it weakens the signal without breaking anything electrically.
6.Inspect the reluctor teeth where they can be seen. A chipped or cracked ring produces an error that is periodic rather than constant.
7.Confirm the sensor is fully seated, correctly torqued, and that no spacer or shim was omitted or added during earlier work.
8.Verify the part number of any previously fitted sensor. A close-but-wrong sensor reads proportionally wrong at all speeds and passes every electrical test.
9.Check whether adaptive values were reset after any recent transmission work, since stale adapts can produce ratios outside the expected window on healthy hardware.

Repair cost

$150 – $3,500

The range on this code is wide because the code itself does not tell you which side of it you are on. If the sensor really is faulty, expect $150 to $400 for an externally mounted one and $350 to $700 where the pan or valve body must come off. A fluid and filter service at $150 to $400 is worth doing where the fluid is degraded, since it addresses slip that a new sensor would not. If the underlying cause is a slipping clutch pack, the conversation moves to a transmission rebuild at $2,000 to $3,500 or more, and no sensor work will change that outcome. This is exactly why the three shaft comparison should come before the parts order rather than after it.

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DIY vs shop

This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.