P0705 — Transmission Range Sensor “A” Circuit (PRNDL Input) #

Note: The code description can change depending on the vehicle manufacturer.

• P0705 — Transmission Range Sensor Circuit Malfunction (Ford, Honda, Hyundai, Kia, Nissan)
• P0705 — Transmission Range Switch Circuit Malfunction (General Motors, Chrysler, Dodge, Jeep)
• P0705 — Transmission Range Sensor “A” Circuit (PRNDL Input) (Toyota, Lexus, Subaru, Mazda)

Summary of code P0705 #

P0705 is a diagnostic trouble code (DTC) indicating a fault detected in the Transmission Range Sensor (TRS) “A” circuit, often referred to as the PRNDL Input circuit. The Transmission Range Sensor (sometimes called the neutral safety switch) is responsible for telling the vehicle’s powertrain control module (PCM) which gear the automatic transmission is in—Park, Reverse, Neutral, Drive, or Low (hence PRNDL). When the PCM detects an electrical problem in this sensor’s circuit, it sets this code. The issue can range from a simple wiring fault to a malfunctioning sensor or even a transmission linkage problem. Prompt attention is important, as this sensor plays a critical safety and drivability role.

Common symptoms for code P0705 #

A malfunction of the Transmission Range Sensor can produce a range of noticeable symptoms, typically related to starting, shifting, and gear indication. These symptoms may appear suddenly or intermittently, depending on how severe the circuit fault is.

• Check Engine Light (CEL) illuminated
• Gear indicator (PRNDL) not matching shifter position
• Transmission stuck in limp or failsafe mode
• No start condition (especially in Park or Neutral)
• Harsh or delayed gear engagement
• Reverse lights not working (in some vehicles)
• Transmission shifting issues (won’t shift, skips gears)

Likely causes of code P0705 (by frequency) #

The most common causes behind a P0705 code are related to either the sensor itself, its wiring, or mechanical issues with the transmission linkage. Environmental factors such as corrosion, water intrusion, or simple wear and tear often play a role, especially on older vehicles or those exposed to harsh climates.

1. Faulty Transmission Range Sensor (TRS) / Neutral Safety Switch
2. Misadjusted or damaged transmission shift linkage
3. Damaged, corroded, or loose electrical connectors or wiring
4. Shorts or opens in the TRS circuit
5. Fluid intrusion into sensor or connector (transmission fluid leak)
6. Failed PCM (rare)

Step-by-step diagnosis for code P0705 #

Diagnosing a P0705 code requires patience and a methodical approach, starting with the most accessible checks before moving to more involved tests. Always follow safety procedures, especially when working near the transmission or starting system.

• 1. Confirm the code and record freeze frame data with a scan tool.
• 2. Visually inspect the Transmission Range Sensor and its connector for corrosion, fluid, or damage.
• 3. Check wiring harnesses between the sensor and PCM for abrasions, pinches, or breaks.
• 4. Verify the position of the shift linkage corresponds to the gear indicator on the dash.
• 5. With the ignition off, disconnect the TRS and check for bent, pushed-out, or corroded pins in the connector.
• 6. Use a multimeter to check for continuity and proper voltage on the TRS circuit per OEM specifications.
• 7. If possible, use scan tool data or a bi-directional control to monitor TRS input while moving the shifter through all positions.
• 8. If all wiring and linkage tests pass, suspect a faulty TRS and replace as needed.
• 9. In rare cases, if the code persists, verify PCM operation and reflash or replace if required (consult OEM procedures).

Possible repairs for code P0705 #

Repairs for code P0705 depend on the underlying cause discovered during diagnosis. Address each issue methodically, starting with the most common solutions.

• Replace faulty Transmission Range Sensor (TRS)/neutral safety switch
• Repair or replace damaged or corroded wiring/connectors
• Adjust or repair transmission shift linkage
• Clean out fluid intrusion and replace affected connectors
• Replace or repair PCM (only after all other possibilities have been exhausted)

Is it safe to drive with code P0705? #

Limited. While some vehicles may still drive with a P0705 code, it is generally not advisable. The sensor is crucial for safe starting and proper shifting; a malfunction can lead to no-start conditions, unexpected gear engagement, or the transmission entering failsafe mode (limp mode), restricting speed and performance. On some vehicles, reverse lights or safety interlocks may also be compromised. Driving should be limited to moving the vehicle to a repair facility and avoided until the fault is fixed.

Vehicles most commonly affected by code P0705 #

While P0705 can appear on any vehicle with an automatic transmission, some makes and models are more frequently reported due to design or sensor placement. Vehicles often exposed to road salt or moisture are particularly vulnerable.

• Ford Focus, Fusion, Escape, Explorer
• Honda Accord, Civic, CR-V
• Hyundai Elantra, Sonata
• Nissan Altima, Sentra, Maxima
• Toyota Camry, Corolla, RAV4
• Chevrolet Malibu, Equinox
• Chrysler Town & Country, Dodge Caravan

Common mistakes & best practices for code P0705 #

Misdiagnosis is common with P0705 when technicians overlook the basics or misinterpret symptoms. Following best practices helps prevent unnecessary repairs and ensures a proper fix.

• Replacing the TRS without first checking wiring and connectors
• Overlooking transmission linkage adjustment or mechanical faults
• Not checking for fluid intrusion at the sensor plug
• Failing to clear the code and verify system operation after repair
• Assuming the PCM is at fault before confirming all other possibilities

Express FAQ for code P0705 #

Still have questions? Here are quick answers to the most common concerns around P0705.

• Q: Can a bad Transmission Range Sensor cause my car to not start?
  A: Yes, if the sensor fails to indicate Park or Neutral, the vehicle’s safety interlock can prevent starting.
• Q: Will replacing the sensor always fix the problem?
  A: Not always. Wiring faults, connector issues, or mechanical linkage problems may also be the cause. A thorough diagnosis is key.
• Q: Is this repair expensive?
  A: Costs vary by vehicle. Replacing the sensor itself is often affordable, but additional wiring or linkage repairs can add to the bill.