The EOBD/OBDII error code P0705 indicates a problem with the Transmission Range Sensor (TRS) circuit. This sensor, crucial for communicating the gear position (Park, Reverse, Neutral, Drive) to the Powertrain Control Module (PCM) or Transmission Control Module (TCM), can cause various drivability issues when malfunctioning. This article explores the symptoms, causes, and repair solutions for the P0705 error code.
What Does the P0705 Code Mean?
The P0705 code signifies a general fault within the TRS circuit. The PCM/TCM isn’t receiving the correct signal from the TRS, indicating a potential issue with the sensor itself, wiring, or connectors. This malfunction can lead to improper gear detection, affecting various vehicle functions. For example, the vehicle might not start, shift erratically, or the backup lights might not function correctly. The PCM/TCM relies on the TRS signal to manage engine operation and shifting based on the selected gear. A faulty signal disrupts this process.
Symptoms of a P0705 Error Code
While the illuminated check engine light (Malfunction Indicator Lamp – MIL) and the stored P0705 code are the primary indicators, other noticeable symptoms can accompany this error:
- Malfunctioning Backup Lights: The backup lights might not illuminate when the gear selector is in Reverse.
- Starting Issues: The vehicle may start in any gear or refuse to start altogether.
- Erratic Shifting: The transmission might shift harshly, unpredictably, or refuse to shift into certain gears.
- Reduced Fuel Economy: Incorrect gear selection can lead to inefficient engine operation and decreased fuel mileage.
Common Causes of the P0705 Code
The P0705 code generally points to an electrical fault within the TRS circuit. Common culprits include:
- Faulty TRS Sensor: The sensor itself can malfunction due to internal damage, corrosion, or wear and tear.
- Wiring Problems: Damaged, corroded, or frayed wiring in the TRS circuit can disrupt the signal transmission.
- Connector Issues: Loose, corroded, or damaged connectors can prevent proper electrical contact.
- Damaged Wiring Harness: The wiring harness containing the TRS circuit wires can be damaged due to exposure to heat, vibration, or physical impact.
P0705 Code Repair Solutions
Troubleshooting the P0705 code involves inspecting the TRS circuit components:
- Locate the TRS Sensor: Determine whether the TRS is internal (inside the transmission) or external. External sensors are generally easier to access.
- Inspect Connectors and Wiring: Visually inspect the TRS connector and wiring for damage, corrosion, or loose connections. Clean or replace as needed.
- Test the TRS Sensor: Use a multimeter or a diagnostic scanner to test the sensor’s resistance and voltage output. Compare the readings to manufacturer specifications.
- Replace the TRS Sensor: If the sensor is faulty, replace it with a new one. For internal sensors, this might require removing and disassembling the transmission, a complex task best left to professionals.
- Check the O-Ring Seal (Internal Sensors): If replacing an internal TRS, ensure the O-ring seal is in good condition to prevent fluid leaks.
- Clear the Code: After performing repairs, clear the P0705 code using an OBDII scanner and verify the issue is resolved.
