OBD-II trouble code
P0907: Gate Select Position Circuit High
The gate select position signal is sitting above its legal ceiling. One thirty-second test — unplug the sensor and watch what the reading does — splits this into two entirely different repairs.
Quick facts
- System
- Powertrain
- Category
- Transmission / Shift Control
- Severity
- High severity
- Drivable
- No — stop driving until repaired
- Repair cost range
- $100 – $2,400
- DIY difficulty
- Advanced DIY
What does P0907 mean?
P0907 is stored when the module reads the gate select position signal above the maximum voltage the sensor is capable of producing legitimately. The gate select axis is the sideways movement of the internal shift mechanism on an automated manual or dual-clutch transmission — the movement that chooses which pair of gears the shift finger can engage — and the module needs a trustworthy position from it before it will commit to any gear change.
There is a test on this code that is faster than any measurement and most people skip it. Disconnect the sensor and look at the reading again. The signal line is pulled up inside the module, so with nothing attached it should climb to the supply rail and the code should persist. If it does, the module and its pull-up are behaving normally and the fault lies between the two connectors — an open circuit, a break, or a short onto something at a higher potential. If instead the reading collapses when the sensor is removed, the sensor itself was driving the line high and the harness is exonerated. Thirty seconds of work eliminates half the possible causes and it costs nothing.
When the harness is implicated, the useful question is not "where is the wire damaged" but "what is it lying next to". A signal circuit does not become high on its own; something at battery voltage has to reach it. The gate select sensor's loom shares its route with circuits that are alive at key-on — the reverse lamp feed, the actuator supply legs, and on many designs the transmission range switch outputs. That gives you a free confirmation available from the driver's seat: if the reverse lights come on with the key and the selector in a forward gate, the short has been located without a meter coming out of the bag. Chafe damage rarely affects only one conductor in a loom, so what the neighbours are doing is evidence.
One caution about resistance measurements on this code. Whether a resistance reading means anything depends on where the pull-up lives, and that varies by design. On a circuit pulled up inside the module, measuring resistance from the signal pin to ground with the module connected gives a number that reflects the module's internal network rather than the wiring, and people have condemned good harnesses on the strength of it. Disconnect both ends before measuring, or the number is not describing what you think it is.
Common causes
- Open circuit in the gate select position sensor signal or ground path
- Short to battery voltage from an adjacent circuit in the same loom
- Failed sensor element driving its output to the supply rail
- Corroded terminal producing a high-resistance joint in the ground return
- Chafed loom section where several conductors have been damaged together
- Connector disturbed or incorrectly reconnected after transmission work
- Water intrusion bridging the signal terminal to a powered terminal
- Reference voltage circuit shorted to the signal circuit inside the harness
- Internal failure of the sensor input stage within the transmission control module
- Aftermarket wiring, trailer harness or alarm splice introduced into the loom
Symptoms
- Transmission unable to select a gear and remaining in neutral
- No drive available despite the engine running normally
- Warning lamp with a transmission fault message
- Reverse lamps illuminated at the wrong time, indicating a shared short
- Gear indicator showing a fixed or implausible value
- Crank-no-start on designs where gate position feeds the start permission
- Additional gate select or shift actuator codes stored alongside
- Fault present constantly from key-on rather than appearing while driving
- Vehicle entering a protective mode with gears restricted or unavailable
- Symptom appearing immediately after recent electrical or bodywork repairs
Diagnostic steps
- 1.Read the live gate select position value with the key on and note whether it is pinned at the top of its range or merely elevated.
- 2.Disconnect the sensor and re-read the value: a reading that stays high proves the module and pull-up are working and moves the search into the harness, while a reading that collapses implicates the sensor.
- 3.If the harness is implicated, check the circuits routed alongside it — reverse lamps, actuator supply and range switch outputs — for abnormal behaviour that would identify the source of the voltage.
- 4.Measure for voltage on the disconnected signal circuit with the key on; anything above the sensor's own supply confirms a short to a powered conductor.
- 5.Check continuity of the sensor ground return separately, since a lost ground raises the signal without any short being present.
- 6.Disconnect both ends before taking any resistance measurement, because a module-side pull-up network will otherwise dominate the reading.
- 7.Inspect the loom for a chafe point that has damaged multiple conductors, rather than assuming a single-wire fault.
- 8.Examine the connector for water intrusion and for terminal-to-terminal bridging, which produces this code without any harness damage at all.
- 9.Compare the sensor's output against specification across its travel where the design allows the mechanism to be moved.
- 10.After the repair, clear codes, run the position learning procedure and confirm the reported positions track correctly across the full select travel.
Repair cost
$100 – $2,400
Diagnosis is $130 to $300 and, on this code specifically, most of that value is delivered in the first minute by the disconnect test. A short to a powered circuit repaired at the chafe point is $150 to $600 depending on how buried the loom is and how many conductors were damaged together — chafe rarely spares the neighbours, so budget for a section repair rather than a single splice. An open circuit or corroded ground repaired at the bulkhead connector is $100 to $400. A gate select position sensor replaced externally is $200 to $850 fitted with the learning procedure. Where the sensor is internal or part of the actuator assembly, $1,200 to $2,400 including programming. A failed input stage inside the transmission control module sits at the top of the range at $900 to $2,200 with coding, and should only be diagnosed after the sensor and the wiring have both been proven good.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with gate select position sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an advanced DIY job. It typically requires specialty tools, scan-tool access, lifting equipment, or careful sequencing to avoid causing new failures. Plan for extended downtime and have a backup vehicle. Most owners are better served by a shop that has done this repair before.