What it means
The signal in park position sensor or switch A circuit is above the expected range.
At a glance
- Usually lights the check-engine light
How it works
Park position sensor or switch A sends its signal to the transmission control module through circuit A. P07B4 sets when the signal rises above the expected range, which can indicate a short to battery voltage or a supply wire contacting B+; this is distinct from a low signal.
Common causes
Most likely first.
- Wire shorted to battery voltage
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
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
- Save freeze-frame data and check live data for sensor A's signal to confirm when it reads high and whether the condition is constant or operating-related.
- Inspect circuit A wiring for pinching, melted insulation, or contact with a battery-voltage source.
- Check sensor A and module connectors for corrosion, damaged terminals, or incorrect pin contact that could put voltage on the signal.
- Following the wiring diagram, test circuit A for an unintended connection to battery voltage using the manufacturer's procedure.
- If the harness and connectors pass, test sensor or switch A and the module input against the manufacturer's specification.
Common fixes
- Reroute and secure circuit A away from a B+ source if contact or pinching is found.
- Repair insulation damage or a short to battery voltage in circuit A.
- Clean or repair damaged terminals at sensor A or the module connector.
- Replace sensor or switch A, or repair the module input, only if testing confirms that component is causing the high signal.
Can I keep driving?
Use the parking brake and verify the vehicle is secure when parked; the code alone does not confirm park interlock behavior. Avoid driving if the gear display, shifting, or transmission operation is unpredictable.
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.