Trouble Code P0708 – Transmission Range Sensor Circuit High Input, Causes and How to Fix
Content
- What is error code P0708?
- Meaning and decoding of error code P0708 📊
- P0708 Error Code Symptoms 🚨 (How to Know There's a Problem?)
- Main causes of error code P0708 ⚠
- How to Diagnose Error Code P0708? 🛠 (Step-by-Step Guide)
- How to Fix Error Code P0708? 🔧 (Troubleshooting)
- Frequently Asked Questions (FAQ) ❓
- Error code P0708 in different cars 🚘
- Related OBD2 Errors 🔗
- Conclusion (What to do if you have a P0708 error code?) ✅
What is error code P0708?
Trouble code P0708 indicates that the transmission range sensor (TRS) circuit has a voltage level that is too high.
This system is responsible for recognizing the transmission mode selected by the driver (gear lever position) and transmits this information to the engine or gearbox ECU.
P0708 affects the operation of the automatic transmission, shift position sensors, and overall engine safety.
The P0708 error code can lead to an increased risk of unstable transmission operation and even damage to the transmission mechanisms if it is not corrected in time.
Meaning and decoding of error code P0708 📊
P0708 – Transmission Range Sensor Circuit High Input
P0708 means that the ECM has detected an unusually high voltage at the input of the shift lever position sensor. This may indicate a short circuit, a faulty circuit, or a faulty sensor itself.
Most often found on Hyundai, Kia, Ford, Chevrolet, Honda vehicles with automatic transmission.
| Code | Description | Possible problems |
|---|---|---|
| P0708 | High Voltage in Transmission Range Sensor Circuit | Short circuit, damaged sensor, open circuit |
P0708 Error Code Symptoms 🚨 (How to Know There's a Problem?)
- Difficulty shifting gears
- The car does not respond to mode selection (eg D or R)
- Gearbox position indicator blinks or lights up incorrectly
- The engine cannot be started in all lever positions.
- Transmission goes into limp mode
- Check Engine Light Comes On
💡 Important! The problem may occur periodically, especially with high humidity or sudden temperature changes. This complicates diagnostics and requires a careful approach.
Main causes of error code P0708 ⚠
- Damaged transmission position sensor
- Corrosion or oxidation of the sensor connector contacts
- Damage to the wiring harness (chafing, breakage, short circuit)
- Malfunction of the transmission control unit
| Possible reason | How to check? |
|---|---|
| Transmission Range Sensor | Check the resistance and response when changing positions |
| Damaged wiring | Visual inspection, test with a tester |
| Corrosion of connectors | Dismantling and checking contacts, cleaning |
| Transmission ECU failures | Scanning error codes, analyzing operation logic |
How to Diagnose Error Code P0708? 🛠 (Step-by-Step Guide)
✅ Step 1: Read error codes with an OBD2 scanner
✅ Step 2: Check if the transmission mode is displayed correctly on the panel
✅ Step 3: Conduct a visual inspection of the sensor and its connector
✅ Step 4: Test the circuits for short circuits or open circuits
✅ Step 5: Check the signal from the sensor when changing the position of the gearshift lever
🛠 Tools you will need:
- OBD2 scanner
- Multimeter (tester)
- Set of keys and screwdrivers
- Dielectric grease and contact cleaner
How to Fix Error Code P0708? 🔧 (Troubleshooting)
Simple methods of elimination ✅
- Reset error codes and recheck
- Cleaning the connectors and sensor contacts
- Checking and replacing fuses
Deep diagnostics and repair ⚙
- Replacing the transmission position sensor
- Repair or replacement of damaged wiring harness
- Reflashing or replacing the transmission ECU (in rare cases)
| Symptom | Possible Solution |
|---|---|
| D or R mode does not work | Check and replace TRS sensor |
| The car does not start | Check the connectors and power supply of the sensor |
| Delayed switching | Transmission ECU Diagnostics |
How to check error code P0708? 🎥 (Video tutorial)
Frequently Asked Questions (FAQ) ❓
Is it okay to drive with a P0708 error code?
Not recommended, as the malfunction may lead to incorrect operation of the transmission, loss of control of gearbox modes and failure of the gearbox.
How quickly can I fix the P0708 code?
If the cause is contamination or oxidation of contacts, it can be eliminated in 30-60 minutes. If it is necessary to replace the sensor or repair the wiring, more time and diagnostics will be required.
Can I diagnose P0708 myself?
Yes, if you have an OBD2 scanner and a multimeter, you can perform basic diagnostics and identify faults in connectors or wiring.
Is P0708 always a sensor issue?
No, there could also be problems with the wiring, connectors or transmission control unit. A comprehensive inspection is required.
Will P0708 reset after battery disconnect?
Sometimes the code may disappear temporarily, but if the fault remains, the error will reappear after a few engine starts.
Error code P0708 in different cars 🚘
P0708 in Hyundai Elantra
Often associated with TRS sensor wear, especially in very wet conditions. Temporary transmission failure possible.
P0708 in Kia Sportage
The problem appears when starting the engine - the gearbox does not exit the parking mode. It is necessary to check the sensor and wiring harness.
P0708 в Ford Focus
On these cars, the wiring under the bottom is often damaged due to corrosion. It is necessary to inspect the connections and possibly replace the harness.
P0708 in Chevrolet Cruze
The error appears due to incorrect sensor adjustment when replacing the transmission. Recalibration is required.
P0708 in Honda Accord
Typical cause is damage to the sensor connector due to vibration. It is recommended to replace the connector and tighten the harness.
Related OBD2 Errors 🔗
P0705 – Incorrect transmission range sensor signal
Description: Incorrect value received from TRS. Possible causes:
- Sensor damage
- Signal circuit break
- Transmission ECU failure
P0706 – Invalid TRS data range
Description: The signal is out of range. Possible causes:
- The sensor itself is faulty
- Poor contact in the connector
- Wire insulation fault
P0850 – Parking position signal circuit malfunction
Description: The ECU does not receive a correct signal about the "P" position. Possible causes:
- The parking switch is faulty
- Power failure in the circuit
- Short to ground
Conclusion (What to do if you have a P0708 error code?) ✅
📌 Brief summary: The P0708 code indicates high voltage in the transmission range sensor circuit, which can be caused by a faulty sensor itself, wiring problems, or a faulty control module.
🚀 Helpful Hint: If the error persists after visual inspection and cleaning of contacts, replace the TRS sensor. When performing any intervention, make sure that the gearshift lever is in the "P" position and the ignition is on, but the engine is not running.
