OBD-II trouble code
P0807: Clutch Position Sensor Circuit Low
Signal voltage has fallen below the lowest value a real pedal position could produce. Two candidate faults explain it, and a single disconnect test separates them in about five minutes.
Quick facts
- System
- Powertrain
- Category
- Transmission / Shift Control
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $90 – $500
- DIY difficulty
- Intermediate DIY
What does P0807 mean?
This is the most decisively testable member of the clutch position sensor family, and that is the practical reason to treat it differently from its siblings rather than as one more variation on the same theme.
A position sensor is supplied with a reference voltage, usually five volts, and returns a fraction of it that corresponds to where the pedal is. Even with the pedal fully released the returned value should sit meaningfully above zero — manufacturers deliberately design in that offset so a genuinely dead circuit can be told apart from a legitimately released pedal. When the module sees a value below that designed-in floor, it knows something is pulling the signal line toward ground harder than the sensor ever would, and stores P0807.
There are only two ways that happens. Either the sensor itself has failed internally and is grounding its own output, or something outside the sensor is grounding the wire — a chafe against the pedal bracket, a crushed section of loom, water bridging pins in a wet connector. A third possibility looks the same from the module's side without being a short at all: if the reference voltage has been lost, the sensor has nothing to divide and its output collapses to near zero, which the module reads as low.
The test that separates these is simple and it is specific to the low variant. Unplug the sensor and watch the signal value with the ignition on. If the reported value rises toward the top of its range, the harness is clean and the sensor was pulling its own output down — replace the sensor. If it stays at the bottom with the sensor disconnected, the sensor cannot be responsible and the fault is in the wiring or the connector. That is a definitive answer for the cost of a connector release clip, and it is why P0807 should almost never end in a guessed part.
One broader pattern deserves attention here more than on the other members. The five-volt reference is rarely dedicated to a single sensor — it is generated in the module and distributed to several. A wire shorted to ground anywhere on that shared circuit drags the reference down for every sensor on it. So a P0807 arriving alongside a throttle position code, an accelerator pedal code or a pressure sensor code is usually not a clutch problem at all. It is one short, reported by everything downstream of it, and the clutch sensor simply happens to be one of the reporters.
Common causes
- Signal wire shorted to ground by a chafe against the pedal bracket or a body panel edge
- Sensor failed internally with its output element grounded
- Loss of the 5-volt reference at the sensor, collapsing the output to near zero
- Water bridging pins inside a footwell connector, which is the lowest point the cabin wiring reaches
- Crushed section of loom where the harness is clipped tightly against the pedal box
- Short on a shared reference circuit affecting several sensors at once rather than this one alone
- Bent or pushed-back pin in the connector making intermittent contact with the connector shell
- Corrosion inside the sensor body after long-term moisture exposure
- Damage from aftermarket wiring spliced into the footwell loom for an alarm, remote start or dash camera
Symptoms
- Check engine light with the vehicle otherwise driving normally
- Stop-start disabled and refusing to shut the engine down
- Hill-hold unavailable
- Cruise control will not engage
- Several unrelated sensor codes stored at the same time, indicating a shared reference problem
- Reported clutch position stuck at or near zero regardless of pedal movement
- Harsher engagement from rest as anti-stall intervention is withdrawn
- On automated manual and dual-clutch vehicles, refusal to select a gear or to move
- Fault appearing after work in the footwell or after an accessory was wired in
Diagnostic steps
- 1.Read the live clutch position value with the ignition on and the pedal released. A value sitting at or near zero rather than at the specified rest offset confirms the code rather than merely repeating it.
- 2.Check whether other sensors have stored codes at the same time. If they have, stop working on the clutch sensor and go after the shared 5-volt reference first — one short explains all of them.
- 3.Disconnect the sensor and watch the reported value with the ignition on. Rising toward full scale means the harness is good and the sensor was pulling its output down. Staying at the bottom means the sensor is innocent.
- 4.With the sensor still disconnected, measure the reference voltage at the harness side. Missing or low reference explains a low signal without any short on the signal wire itself.
- 5.Check the signal wire for continuity to ground with the sensor unplugged and the module connector unplugged. Any reading close to a dead short confirms a chafe or a crush.
- 6.Inspect the connector under good light for water, corrosion, and pins that have been pushed back out of their locks. Footwell connectors take moisture off shoes year-round.
- 7.Follow the loom along the pedal box and through the bulkhead grommet, looking for the shiny worn patch where insulation has been rubbed through against a bracket edge.
- 8.Look for evidence of accessory wiring spliced into this loom. Alarm and remote start installations frequently use the clutch circuit and are a recurring cause of shorts in this area.
- 9.If the sensor is replaced, run the clutch position adaptation afterward so the module learns the new part's endpoints.
Repair cost
$90 – $500
The disconnect test decides which side of this range you land on, which is why it is worth doing before buying anything. If the sensor is at fault it is $30 to $220 for the part with 0.4 to 1.8 hours of labour, so around $110 to $450 fitted. If the harness is at fault the sensor is not needed at all: repairing a chafe or a crushed section is typically $120 to $300, and cleaning or replacing a corroded connector can be under $150. Diagnosis is $90 to $150. A short on a shared reference circuit is the expensive scenario because the fault can be anywhere on a branch serving several sensors, and tracing it is charged by the hour.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with clutch position sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
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.