P0707 Code: Transmission Range Sensor A Circuit Low
The range sensor signal voltage is below its lowest valid value – usually a short to ground or lost 5 V feed.
At a glance
Severity: Moderate
- Meaning
- Transmission Range Sensor A Circuit Low
- System
- Transmission · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $60–$1,500
- DIY difficulty
- Moderate
P0707 is used on vehicles whose range sensor sends a variable voltage (or a coded signal) rather than a set of simple on/off switches. The module supplies a 5-volt reference, and each lever position produces its own voltage step somewhere between roughly 0.5 and 4.5 volts. If the signal falls below the lowest step – close to zero – the module stores P0707, because no real lever position can produce that value. The usual suspects are a signal wire rubbing through to ground, a reference feed that has collapsed, or a sensor with an internal short, often after water got in. On cars with switch-type sensors the same fault shows up as P0705 instead.
Can I keep driving? Many cars fall back to a fixed gear or refuse to start when the lever position is unknown. If yours drives, go straight to a shop without towing or long trips, and always use the parking brake – the car may not know it is in Park.
How to read P0707
- P Powertrain
- 0 Generic (SAE)
- 7 Transmission
- 07 Specific fault
Symptoms
- No crank in any lever position, or only after several tries
- Gear display stuck on one letter or blank
- Transmission in limp mode with a single forward gear
- Reverse lights inoperative
- Other sensor codes at the same time if a shared 5 V reference is pulled down
- Check engine light, often with P0700
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Signal wire chafed and shorted to ground on the case, bracket or exhaust shield
- Range sensor internally shorted, often after water intrusion
- 5 V reference circuit open or pulled down by another shorted sensor
- Corroded connector creating a path to ground
- Transmission module input or reference driver fault
Diagnosis step by step
Read the raw range voltage
Many scan tools show the range signal in volts as well as the letter. A reading near 0 V in every position confirms the low fault; normal steps in some positions and a drop in one position point to a worn track in the sensor instead.
Tools: OBD-II scanner
Check for other reference-voltage codes
Look for codes on other 5 V sensors on the same module, such as a reference circuit low. If several sensors are affected, unplug them one at a time – the one whose removal brings the reference back to 5 V is the shorted part.
Tools: OBD-II scanner
Measure the 5 V reference and ground
Unplug the range sensor and, key on, measure between reference and ground pins at the harness side. Expect about 4.8–5.2 V; less than that with the sensor unplugged means a wiring or module problem, not the sensor.
Tools: Multimeter
Check the signal wire for a short to ground
Key off, disconnect the sensor and the module, then measure resistance from the signal wire to chassis ground. It should be open (no continuity); any reading in ohms means the insulation is damaged somewhere along the run.
Tools: Multimeter
Measure the sensor itself
Measure resistance between the sensor pins while you move the shift shaft. The value should change in steps from position to position; a near-zero reading between signal and ground pins means the sensor is shorted internally.
Tools: Multimeter
Where the parts are
- 1Battery
- 2Alternator
- 3Engine computer (ECM)
- 4CAN bus
- 5Transmission
- 6Wheel speed sensor
- 7High-voltage battery
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Repair chafed signal or reference wire | No | $120–$350 |
| Clean connector and replace seal | Yes | $60–$160 |
| Replace range sensor and align | Yes | $180–$450 |
| Replace transmission control module (programming) | No | $600–$1,500 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Field data
| Ford | 24 | F-150 SUPERCAB, F-150 CREW CAB, Expedition |
|---|
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
The code keeps the check engine light on, so the vehicle fails an OBD emissions or smog test. Repair the short and confirm the light stays off after a couple of drives.
Frequently asked questions
Why do I have P0707 and not P0705?
It depends on the sensor type. Range sensors that output a voltage use separate low and high codes (P0707/P0708), while switch-type sensors usually report any fault as P0705. The low code narrows the search to a short to ground or a lost supply.
Could another sensor cause P0707?
Yes. Several sensors often share one 5 V reference from the same module. A short in any of them pulls the whole reference down, and the range sensor – among others – then reads low.
Why won't the car start at all?
With no valid Park or Neutral signal, the starter enable is blocked for safety. Some models allow a start in Neutral once the lever is moved; if none work, the sensor circuit has to be repaired before the car can be driven.
Is replacing the sensor always the fix?
No. If the reference voltage is low even with the sensor unplugged, a new sensor won't help – the short is in the harness or another component on the same circuit.