What it means
The primary transmission range sensor A (PRNDL switch position) reports voltage below the plausible range - signal shorted to ground or sensor fault.
At a glance
- Usually lights the check-engine light
How it works
Transmission range sensor A reports the selected gear position, such as Park, Reverse, Neutral, or Drive, to the transmission control module. The module sets P0707 when sensor A's signal is lower than the range it considers valid, which can happen if the signal wire is grounded or the sensor circuit has a fault.
Common causes
Most likely first.
- Signal shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Record freeze-frame data and compare the scan tool's transmission range reading with the shifter position to see when the low signal occurs.
- With the vehicle safely parked, move the selector through its positions and check whether the displayed range changes correctly or drops out.
- Inspect the range sensor A connector and harness for corrosion, loose or pushed-back pins, and insulation rubbed through to ground.
- Check the sensor A signal wire for a short to ground and inspect its connector contacts for excessive resistance, following the vehicle wiring diagram.
- If wiring checks pass, test transmission range sensor A and its adjustment according to the manufacturer's specification.
Common fixes
- Clean and secure corroded or loose transmission range sensor A connector terminals.
- Repair chafed wiring or a signal wire shorted to ground.
- Replace a damaged connector or terminal that cannot maintain contact.
- Adjust or replace transmission range sensor A if it fails testing.
Can I keep driving?
If the vehicle selects gears normally, drive only as needed and avoid long trips until the fault is diagnosed. If the displayed gear is wrong, shifting is harsh or delayed, or the transmission slips, stop driving and arrange recovery because loss of correct range information can make gear selection unsafe or damage the transmission.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.