A problem with an automatic transmission is always a serious concern for car owners, and the appearance of a code P1706 on the on-board computer Nissan often becomes the first signal of serious problems. This diagnostic code indicates an incorrect signal from the TR switch that does not correspond to the actual position of the lever or is missing at all. Without timely intervention, the problem can lead to the engine being unable to start or causing erratic gear changes.
Many owners Nissan Qashqai, X-Trail or Teana are faced with the fact that the car stops responding correctly to the driver’s commands, going into emergency mode. In this case, the electronic control unit (ECU) cannot determine which mode the box is in, which blocks the fuel supply to start the engine. To avoid costly transmission repairs, it is necessary to quickly and accurately understand the causes of this error, since it is often associated not with the unit itself, but with the electrical circuit or connectors.
The essence of the malfunction and the operation of the security system
Code P1706 in technical documentation Nissan is interpreted as “Selector Position Switch: Low Voltage Circuit” or “Position Signal Invalid.” The electronic control unit constantly compares the data received from the selector position sensor (TR sensor) with other engine and transmission operating parameters. If the signal is interrupted or shows a value that is physically impossible given the current state of the lever, the system records a failure.
In modern models such as Nissan Murano or Pathfinder, this system is integrated into the overall security logic. If the ECU does not see a clear signal that the lever is in the “P” (Park) or “N” (Neutral) position, it prohibits the engine from starting. This is done to prevent accidental movement of the car when the engine starts. The error can manifest itself either in the form of the “Check Engine” lamp coming on, or in the form of a complete blocking of the starter when the key is turned.
Sometimes the problem is temporary and is associated with unstable contact in the connector, but more often it is a sign of wear on the sensor itself or damage to the wiring. ECU detects an error even in the event of a short-term signal loss, which requires a thorough check of all links in the chain.
Common Causes of Code P1706
There can be several reasons for this error, and they range from banal oxidation of contacts to serious damage to the internal components of the transmission. The first and most common problem is a malfunction of the selector position switch itself, which over time loses its properties or breaks mechanically. Under harsh operating conditions, especially in regions with frequent temperature changes, the plastic housing of the sensor may crack and the contacts may oxidize.
The second common cause is a break or short circuit in the wiring harness running from the transmission to the control unit. Mechanical damage to the insulation, rubbing of wires against the body, or aggressive exposure to reagents on the roads can lead to disruption of the integrity of the circuit. It is also worth paying attention to the condition of the connection connector, where moisture and dirt often accumulate.
In addition, problems may arise due to incorrect adjustment of the gearshift cable. If the selector lever does not coincide with the position of the mechanism inside the box, the sensor will produce incorrect coordinates. In rare cases, the transmission control module (TCM) itself becomes the culprit, but this happens much less often than failure of external components.
- ⚠️ Oxidation of contacts in the selector position switch connector.
- ⚠️ Mechanical destruction of the plastic housing of the TR sensor.
- ⚠️ Broken wiring in the harness going to the automatic transmission.
- ⚠️ Incorrect installation or misalignment of the gear shift cable.
Diagnostics and testing of the electrical circuit
To accurately identify the cause of the error, it is necessary to conduct a comprehensive diagnosis using a multimeter and a diagnostic scanner. Start by visually inspecting the connector on the transmission: it should be clean, dry and tightly connected. If you see traces of corrosion or oil, you must thoroughly clean the contacts and dry them before further manipulation.
The next step is to check the integrity of the wires. You need to measure the resistance in the sensor's power and ground circuits. If the multimeter shows infinite resistance, then there is a break somewhere. If the resistance tends to zero when checking for ground, most likely there is a short circuit. Check the wires for chafing at bends and near moving body parts.
It is also important to check the position sensor itself. To do this, you need to remove the connector and measure the resistance between the terminals at different positions of the selector lever. Compare the obtained values with the reference data for your car model. If the resistance changes abruptly or is absent in certain positions, the sensor must be replaced.
- Check Engine light came on
- Car won't start
- Automatic transmission in emergency mode
- The error goes away on its own
Step-by-step instructions for troubleshooting
Troubleshooting P1706 requires a consistent approach and accuracy when working with electrical and transmission components. If you determine that the problem is in the connector, try cleaning it and treating it with contact lubricant. If a wire break is detected, it must be insulated or a section of the harness must be replaced using high-quality heat shrink.
If the sensor fails, replacing it is the most reliable way to solve the problem. To do this, you will need to remove the old switch and install a new one, following the exact sequence of actions. It is important not to over-tighten the mounting bolts to avoid damaging the fragile plastic housing of the new element.
After replacement or repair, it is necessary to reset the error through the diagnostic scanner and check the operation of the system at idle. Make sure that when you shift the lever, the correct position is displayed on the instrument panel and the engine starts only in the “P” and “N” positions. If the error returns, more advanced diagnostics or TCM replacement may be required.
☑️ Check before replacing the sensor
Interconnection with other vehicle systems
Error P1706 rarely exists in isolation and is often accompanied by other trouble codes that can confuse the inexperienced diagnostician. For example, errors may appear related to the speed sensor or pressure in the valve body, since the ECU receives conflicting information about the operation of the transmission. It is important to analyze the entire list of errors, not just P1706.
On some models Nissan With a continuously variable transmission (CVT), this error can cause the solenoids to lock up, making gear shifting impossible. In such cases, the car may move in only one gear or come to a complete stop. This creates serious risks on the road, so the problem cannot be ignored.
It is also worth considering that a malfunction of the position sensor can affect the operation of the push-button start system (Start/Stop) and the Start-Stop function. If the system does not receive confirmation of the position of the selector, it may refuse to start the engine even with a working starter and battery. Therefore, diagnosis must be comprehensive.
Why might the error return after a reset?
If you simply reset the error with the scanner without eliminating the physical cause (break, oxidation), the controller will again record an incorrect signal on the first attempt to start. This is the standard logic of the ECU: it does not remember the error, but constantly monitors the parameters in real time.
Before starting work on replacing the sensor, be sure to disconnect the negative terminal of the battery. This will protect the electronic components from short circuits and accidental activation of the starter.
Repair specifics for various Nissan models
Owners of different models Nissan may encounter features of the location and design of the selector position sensor. For example, on Nissan Qashqai And X-Trail first generation, the sensor is often located on the side of the box and is easily accessible, whereas on Nissan Teana or Murano Access may be difficult due to the tight layout of the engine compartment.
For models with engine VQ25DE or VQ35DE There is often a problem with oxidation of contacts due to condensation. In such cases, it is recommended not only to clean the connector, but also to replace it with a new one with a sealed cover. On Nissan Patrol And Patrol Y61 the problem may be due to vibration, which loosens the sensor.
When choosing a spare part, it is important to pay attention to the manufacturer. Original sensors Nissan have a higher service life and accuracy than cheap analogues. The use of low-quality parts often leads to the reappearance of the error after a short time. The table below shows features for popular models:
| Model | Sensor Features | Difficulty of access | Common reason |
|---|---|---|---|
| Nissan Qashqai | Built into the automatic transmission housing | Average | Oxidation of contacts |
| Nissan X-Trail | Separate module | Low | Rope position |
| Nissan Teana | Complex body shape | High | Mechanical wear |
| Nissan Patrol | Reinforced fasteners | Low | Vibration and shaking |
Prevention and long-term reliability
To avoid the error reappearing P1706, it is necessary to regularly carry out preventive inspections of the transmission and its electrical components. First of all, this concerns checking the condition of the anthers and protective covers on the connectors. If they are damaged, moisture and dirt will inevitably get inside, causing corrosion.
It is also recommended to monitor the tension of the gearshift cable. Over time, it can stretch or weaken, causing the selector to position inaccurately. Regular diagnostics at a service station with the connection of a scanner will help identify deviations in the operation of sensors before they lead to complete system failure.
The use of high-quality transmission fluids and compliance with the rules for replacing them also indirectly affects the operation of the sensors. Dirty fluid can enter the switching mechanism and contaminate the sensor contacts. Remember that prevention is always cheaper and easier than overhauling the gearbox or replacing expensive electronic components.
Regularly checking the integrity of the connectors and protecting them from moisture is the most effective way to prevent the P1706 code from appearing on Nissan vehicles.
⚠️ Attention: If error P1706 is accompanied by loss of traction or jerking when shifting gears, immediately stop using the vehicle and contact a service center. Continuing to drive can lead to failure of the valve body or planetary gears of the automatic transmission.
FAQ: Frequently asked questions
Is it possible to drive a car with error code P1706?
Driving with this error is highly not recommended, as the car may go into emergency mode, lose traction, or, worse, stall while driving. In addition, there is a risk that the engine may not be able to start when stopped.
How much does it cost to replace a selector lever position sensor?
The cost of the original sensor varies depending on the car model, but usually ranges from 3,000 to 8,000 rubles. Replacement work takes about 1-2 hours and depends on the difficulty of accessing the connector on a particular model.
Will resetting the error via an OBDII scanner help?
Resetting the error will have a temporary effect. If the physical cause (breakage, oxidation, wear) is not eliminated, the error will return immediately or after several engine starting cycles.
Can I fix the sensor myself?
In most cases, repairing the sensor is impossible, since it is a sealed unit. It is best to replace it with a new original or high-quality analogue. Attempts to open and solder inside often lead to repeated failure.
⚠️ Warning: Do not attempt to start the engine if P1706 indicates an indeterminate selector position. This may cause the vehicle to move suddenly if the shift mechanism is stuck in Drive or Reverse.