P0707
PowertrainTransmission Range Sensor Circuit Low Input
The transmission range sensor is sending a voltage signal that's lower than the gearbox computer will accept, so the car can't reliably tell which gear position you've selected. This sensor, often called the neutral safety switch, tells the ECU whether you're in Park, Reverse, Neutral, Drive, or Low. When it reads too low, the car may refuse to start, drop into limp mode, or shift like it's having a bad day. For the owner it usually comes down to a duff sensor or corroded wiring rather than anything inside the box itself.
ⓘ Information only. This page provides general educational information about fault code P0707. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0707 mean?
P0707 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Transmission Range Sensor Circuit Low Input.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine or gearbox warning light on the dash
- • Engine won't crank in Park or Neutral, or only starts intermittently
- • Gearbox stuck in limp mode, often locked into third gear with no other changes available
- • Harsh, delayed, or wrong-gear shifts when you move the lever to Drive or Reverse
- • Reverse lights not working, since the same switch usually feeds them
- • Selector lever feels notchy or vague moving between positions
Possible causes
Causes commonly associated with P0707, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Faulty range sensor itself, the usual offender. These switches wear with mileage and heat, and the contacts inside go intermittent
- 2. Corroded or damaged wiring and connector at the sensor, very common on cars that have been jet-washed or driven through a lot of British winters
- 3. Sensor knocked out of adjustment, so it reads the wrong position for where the lever actually is
- 4. Poor earth or low supply voltage to the sensor, which can drag the signal below the threshold
- 5. Damaged or stretched shift linkage that no longer lines the selector up with the switch
- 6. Low or filthy transmission fluid upsetting internal sensor operation on boxes that read range internally
- 7. Failed TCM or PCM, the rarest cause and the last thing to suspect
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Scan the car and read live data while moving the gear lever through every position. If the displayed gear lags or sticks at one reading, you've confirmed the switch isn't tracking the lever
- 2. Get under the connector at the sensor and check it properly for green corrosion, water ingress, and pushed-back pins. A dab of cleaner and a reseat fixes a fair share of these before you spend a penny on parts
- 3. Back-probe the signal wires and measure voltage across each gear position against the manual figures. A dead-low or flatline reading points at the sensor or its wiring
- 4. Check continuity and resistance from the sensor plug back to the control module to rule out a chafed or broken wire in the loom
- 5. Confirm the sensor's earth and feed are solid, because a bad earth mimics a failed sensor
- 6. If the lever, fluid, and wiring all check out, suspect the sensor and adjust or replace it, then recalibrate if the box needs it
Common questions about P0707
Will my car get through its MOT with this fault? +
The code on its own isn't a fail, but if the warning light is glowing during the test the examiner can mark it down, and the MIL being lit is what counts. Plenty of cars don't even illuminate the engine light for a pure gearbox sensor fault, so check before you panic. The bigger problem at MOT time is the practical stuff: if reverse lights are out because of the same switch, that's a straight fail you'll need to sort regardless.
What am I looking at to put it right? +
A range sensor on a mainstream car runs roughly £30 to £150 for the part. An independent garage will typically charge somewhere in the low to mid three figures all-in for a diagnose-and-replace, more if access is awkward. A main dealer will be dearer, often pushing toward four figures once you add their labour rate and a recalibration. If it turns out to be nothing more than a corroded plug, a decent garage might sort it for an hour's labour. Internal box work or a control module is where the bill jumps.
How do I tell whether it's the sensor or just dodgy wiring? +
Live data is your friend here. Move the lever through each gear and watch what the scanner reports. If the readings jump around or stick with the wiring undisturbed, the switch is suspect. Then unplug the connector and look hard at the pins. Corrosion, damp, or a pin that's backed out tells you it's a wiring issue you can clean up. If the connector is spotless and the voltage is still dead low across all positions, the sensor itself has had it. Wiggle-testing the loom while watching live data will catch an intermittent break.
Can I sort this myself in the driveway? +
Possibly, depending on the cause. If it's a manky connector, a tin of contact cleaner, a small brush, and a reseat costs you next to nothing and fixes a good number of these. Swapping an external switch is doable with basic tools and a multimeter, though some sit awkwardly under the car and need the alignment set precisely or you'll just throw the code again. What you can't do at home is fix an internal sensor or recalibrate a TCM that needs dealer-level software. Start with the cheap connector check before you order parts.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →