P0705
UniversalTransmission Range Sensor Circuit Malfunction (PRNDL Input)
Medium SeverityThe Transmission Range Sensor (TRS), often called the neutral safety switch, communicates the current gear selection (Park, Reverse, Neutral, Drive, Low) to the engine's computer (PCM). A malfunction in this circuit means the PCM receives incorrect or no information, which can prevent the vehicle from starting, show an inaccurate gear display, or affect transmission shifting.
⚠️ Before You Begin (Safety First)
Always wear appropriate personal protective equipment (PPE) when working on a vehicle. Ensure the vehicle is safely supported on a level surface with the parking brake engaged. Disconnect the battery's negative terminal before performing any electrical work or component replacement to prevent accidental shorts or injury.
Common Symptoms
- Check Engine Light illuminated
- Vehicle will not start (or only starts intermittently in Park or Neutral)
- Incorrect gear display on the dashboard
- Backup lights not working when in Reverse
- Difficulty shifting gears or transmission stuck in limp mode
Common Causes
- Faulty Transmission Range Sensor (TRS)
- Corroded, loose, or damaged electrical connectors at the TRS
- Damaged or shorted wiring in the TRS circuit
- Malfunctioning Powertrain Control Module (PCM) (less common)
- Mechanical issues within the transmission preventing proper sensor activation (rare)
Frequently reported on: Ford F-150 (2004-2008), Chevrolet Silverado (1999-2006), Honda Accord (1998-2002), Toyota Camry (2002-2006)
Diagnostic Steps
- Visually inspect the Transmission Range Sensor and its wiring harness for any obvious signs of damage, corrosion, or loose connections. Ensure the connector is securely attached.
- Disconnect the battery's negative terminal. Using a multimeter, test the continuity and proper voltage at the TRS connector according to your vehicle's specific wiring diagrams. Check for opens or shorts in the circuit.
- If the sensor tests faulty or if no wiring issues are found, replace the Transmission Range Sensor. Ensure the new sensor is properly aligned during installation, following manufacturer specifications.
- Reconnect the battery. Clear the P0705 code using an OBD-II scanner and then test drive the vehicle to confirm the repair and ensure the code does not return.
👨🔧 When to Call a Professional
If you have thoroughly inspected the wiring and connectors, and have replaced the Transmission Range Sensor, but the P0705 code persists, it's crucial to consult a professional automotive technician. The issue may stem from a more complex wiring harness problem, a faulty Powertrain Control Module (PCM), or even an internal transmission mechanical issue that requires specialized diagnostic tools and expertise.
Commonly Asked Questions
Can I drive with a P0705 code?
It is not recommended to drive with a P0705 code. While you might be able to, the issue can cause unreliable starting, incorrect gear display, and unpredictable shifting, which could potentially leave you stranded or create a hazardous situation.
Where is the Transmission Range Sensor located?
The Transmission Range Sensor is typically located on the outside of the transmission case. It's often found near the shift linkage where the manual shift lever connects to the transmission.
Is a P0705 code expensive to fix?
The cost to fix a P0705 code can vary. If it's just the sensor, the part itself is usually inexpensive (between $50-$150), and it can often be a DIY repair. If professional diagnosis, complex wiring repair, or internal transmission work is required, the costs will be significantly higher.
Can a P0705 code cause my car not to start?
Yes, a faulty Transmission Range Sensor is a common cause for a car not starting. The engine computer relies on the TRS to confirm the vehicle is safely in Park or Neutral before allowing the engine to crank, acting as a safety interlock.