The P0705 is considered a generic powertrain code that can be found on a multitude of modern vehicles. What does it mean and how can you fix it?
In this guide, we discuss what the P0705 code means and what symptoms it might cause. We also dive deeper into the ways to fix the code so you can get back on the road.
Code P0705 Definition
P0705 – Transmission Range Sensor Circuit Malfunction (PRNDL input)
What Does the P0705 Code Mean?
The P0705 error code indicates that the Powertrain Control Module (PCM) or Transmission Control Module (TCM) is unable to see the gear shifter position. It indicates that there is an issue with the Transmission Range Sensor (TRS).
It is either sending the wrong signal or the computer can’t read the information.
Either the TCM or ECM is having trouble determining what gear the transmission is in. For this reason, the car might not know if you have the selector in Park, Neutral, Reverse or a gear. Sometimes, the car won’t start because the system can’t tell what gear the vehicle is in.
Failure of an external TRS isn’t uncommon, especially as mileage and age grow. This sensor gets exposed to a lot of weather elements and contamination. Over time, it merely corrodes. However, late-model vehicles hold the transmission range sensor in the valve body. It is separate from the reverse backup light switch and the neutral safety switch.
P0705 Trouble Code Symptoms
The most common symptom of the P0705 trouble code is the Check Engine Light. However, you might also have trouble starting the car or notice it starts while in gear.
Here is the full list of possible symptoms:
- Check Engine Light
- Backup lights may fail
- Inability to put the vehicle in gear
- Vehicle starts when the car isn’t in gear
- Delayed shifting
- Rough shifting
Causes of the P0705 Code
There are several causes possible with the P0705 code. Here are some of the most common:
- Malfunctioning TRS
- Poor connection or damaged wires with the transmission range selector circuit
- Dirty external TRS
- Blockage of internal valve body TRS port
- Defective shift linkage
- Faulty PCM or TCM
How Serious is the P0705 Code?
Medium – This trouble code might not affect the way your car works. However, it could stop you from being able to start your vehicle. It can also allow the car to start without it being in Park, which could be dangerous.
You should resolve the situation promptly if only to protect others from danger.
What Repairs Can Fix the P0705 Code?
This list of fixes might help you resolve the P0705 code. But, you should never throw parts at the problem without first knowing what is defective. Below this, we discuss how to properly diagnose the problem first.
Here are some of the most common fixes to consider:
- Clean and re-establish the connection of the external TRS
- Replace the TRS
- Replace defective wiring to the transmission range selector circuit
- Adjust shift linkage
- Replace valve body
- Replace TCM or PCM
Common P0705 Diagnosis Mistakes
Before any parts are replaced, you should check the transmission fluid and change it if necessary. Contaminated fluid can lead to a lot of transmission issues.
Additionally, don’t replace the TRS without first checking adjustments and cleanliness. There’s no sense moving forward with large repairs when a simple solution will fix it.
Recommended Tools for Diagnosis
- Diagnostic OBD Scan Tool
- Basic Hand Tools
- Auto Repair Manual
- Electrical Contact Cleaner
How to Diagnose the P0705 Trouble Code
Here is a guide showing how a professional would diagnose the P0705 DTC.
- Look for other codes with your OBDII scanner. If there are other issues to repair, do that first.
- Clear the Check Engine Light.
- Check the new freeze frame data to find the new codes.
- If you have an internal transmission range sensor, you might need the help of a shop to go further. These are much harder to diagnose.
- With an external sensor, you can reference the service manual to ensure it is properly adjusted.
- Inspect the wiring of the TRS. Repair any damaged wires or re-establish the connection if there is a problem.
- Replace the transmission range sensor if you can’t find any other issues.
Estimated Cost of Repair
Here are a few examples of costs you might incur when repairing the P0705 trouble code. These prices include parts and labor.
- Clean/re-establish TRS connection – $0
- Transmission Range Sensor – $100-$375
- Wiring Replacement – $50-$750
- Transmission Range Switch Adjustment – $50-$150
- Valve Body – $300-$900
- TCM/PCM – $400-$2,000
Mechanics Tips about the P0705 Code
If the transmission range sensor is located externally from the transmission, it is much easier to work on. You can clean it, check the connection and replace it with ease.
However, if the TRS is located inside the transmission, you might need to replace the valve body or the entire transmission to repair the problem. You could require help from a professional shop if you are dealing with an internal TRS.
Categories: OBD Codes