Car owners who have encountered problems with their cars Nissan, often see an indicator light on the dashboard Check Engine. During computer diagnostics, the scanner produces a code P1700, which indicates a serious malfunction in the transmission control system. This error is related to the vehicle speed sensor (VSS), which provides critical data to the engine control unit (ECU).
Ignoring a malfunction signal can lead to incorrect gear shifting, jerking while driving, and even complete gearbox failure at the most inopportune moment. Model owners Nissan Qashqai, X-Trail and Teana must understand that the P1700 code is not just a warning, but a signal of an open circuit or incorrect data coming from the sensor.
What does the P1700 code mean and how does the system work?
Error code P1700 in technical documentation Nissan stands for “Vehicle Speed Sensor Circuit Malfunction”. The speed sensor is the “eyes” for the electronic control unit, allowing it to determine the current speed and select the optimal gear for the transmission.
The system operates on the principle of generating electrical pulses, the frequency of which is directly proportional to the rotation speed of the transmission output shaft. If the signal disappears, becomes too weak or goes beyond acceptable limits, the control unit records the error and goes into emergency mode.
In limp mode, the car may lock into gear, refuse to shift, or begin shifting only at high speeds. This is necessary to prevent mechanical damage to the internal components of the transmission in the absence of accurate data on the speed of movement.
⚠️ Attention: When error P1700 appears, the control unit may ignore the gas pedal signal in certain modes, which leads to a loss of acceleration dynamics and increased fuel consumption.
It is important to note that the speed sensor is Nissan often integrated into the transmission control module (TCM) or located directly on the transmission housing. Its operation is closely related to the throttle position sensor and the engine speed sensor.
Main causes of malfunction
Reasons for the appearance of the code P1700 can range from simple electrical problems to serious mechanical failures. Most often, the culprit is the speed sensor itself, which over time loses its magnetic properties or fails due to vibrations and temperature changes.
The second most common reason is a violation of the integrity of the wiring. In the engine compartment, wires are constantly exposed to high temperatures, oil and aggressive reagents, which can lead to abrasion of insulation or oxidation of contacts in connectors.
- 🔌 Oxidation of contacts in the connector of the speed sensor or transmission control unit.
- ⚙️ Mechanical damage the speed sensor itself due to impacts or corrosion.
- 🔋 Eating problems — lack of voltage at the sensor due to a blown fuse.
Less often, but it happens that the problem lies not in the sensor, but in the mechanical drive of the sensor itself (if it has a flexible cable) or in the ring gear, which rotates and generates pulses. On modern Nissan With continuously variable transmissions (CVTs), the problem may be with the input shaft gear sensors.
Sometimes the error occurs due to a control unit software failure, especially if the car has recently been reflashed or the battery has been disconnected for a long time without saving the settings.
Symptoms and behavior of the car when there is an error
The presence of error P1700 can be determined not only by the scanner, but also by a change in the car’s behavior on the road. The most obvious sign is the light coming on. Check Engine and indicator AT or SLIP on the dashboard.
The driver may notice that the speedometer begins to show incorrect data or stops working altogether. The needle may jump randomly or freeze at one value, which creates a danger when driving on high-speed highways.
Gear shifts occur with delays or jerks. The car may get stuck in one gear, not wanting to shift to a higher gear, even when accelerating at high speeds. This is due to the fact that the control unit does not receive speed data and cannot correctly calculate the switching moment.
- 🚗 Jerks during acceleration and deceleration due to incorrect gear selection.
- 📉 Power drop engine when trying to move away or overtake.
- 🔊 Enabling emergency mode transmission (Limp Mode) with speed limitation.
In some cases, especially on older models Nissan, the error may be accompanied by difficulty starting the engine, since the security system does not see confirmation of movement or shaft rotation speed.
Diagnostics and testing of the sensor circuit
The first step in troubleshooting a P1700 code is a visual inspection. You need to find the speed sensor on the gearbox and check the integrity of its connector. Often it is enough to simply remove the connector, clean the contacts and reattach it.
For more accurate diagnostics, you will need a multimeter. It is necessary to check the presence of voltage at the sensor contacts. Typically, one of the contacts should have supply voltage (usually 5 or 12 volts, depending on the model), and the other should have ground.
If there is voltage, you need to check the resistance of the sensor itself. To do this, disconnect the connector and measure the resistance between the sensor terminals. The value must correspond to the specifications of the specific vehicle, usually in the range from 200 to 1000 ohms.
1. Подключите мультиметр в режим измерения сопротивления.2. Прикоснитесь щупами к контактам датчика скорости.
3. Если сопротивление бесконечно (обрыв) или равно нулю (короткое замыкание) — датчик неисправен.
You should also check the integrity of the wires going from the sensor to the control unit. Wires often fray where they enter the connector or where they bend. Use a multimeter in continuity mode to check the circuit for an open circuit.
- 🔧 Weight check — make sure that the grounding circuit does not have high resistance.
- ⚡ Power check — make sure that the fuse responsible for the sensor is good.
- 📡 Signal check — when the wheel rotates, the sensor should produce an alternating signal.
If visual inspection and measurements do not reveal problems, the transmission control module (TCM) itself may be faulty and is not processing incoming signals correctly.
- Speedometer doesn't work
- Jerks when switching
- Emergency mode
- Combination of symptoms
Step-by-step instructions for troubleshooting
Troubleshooting P1700 starts with preparation. You will need a tool kit, a multimeter, a new speed sensor (if the old one is faulty) and a good quality contact spray to clean the connectors.
First you need to de-energize the car by disconnecting the negative terminal of the battery. This is a precaution to avoid short circuits when handling wiring and connectors.
☑️ Preparing to replace the sensor
The next stage is dismantling the old sensor. Carefully disconnect the electrical connector by pressing the latch. Unscrew the mounting bolt or nut holding the sensor and remove it from its seat.
Before installing a new sensor, be sure to clean the mounting area of dirt, oil and rust. Apply a thin layer of heat-resistant sealant, if designed, to prevent transmission fluid from entering the housing.
Install a new sensor, tighten the fasteners to the recommended torque (usually no more than 10-15 Nm, so as not to strip the thread). Connect the connector until it clicks and secure it with a clamp to prevent vibration.
⚠️ Attention: When installing a new sensor, make sure that the O-ring is not twisted or left in the seat, otherwise transmission fluid may leak.
After building the system, you need to reset the error. Connect the battery, start the engine and let it idle for a few minutes. Use a diagnostic scan tool to clear the error code from the control unit memory.
If the error returns immediately after a reset, then the problem is not in the sensor itself, but in the wiring or control unit. In this case, a more in-depth diagnosis of the electrical circuit will be required.
What should I do if the P1700 error returns?
If the error returns, check the integrity of the wiring harness going to the control unit. Sometimes the problem lies in the oxidation of the contacts inside the TCM connector itself, which is located in a hard-to-reach place. In rare cases, it is necessary to replace or reflash the transmission control unit.
It is also worth checking the level and condition of the transmission fluid. Low oil level or contamination can affect the operation of the torque converter and sensors located inside the box.
Prevention and maintenance features
To avoid recurrence of the P1700 code, you must regularly inspect the speed sensor and its wiring. This is especially important after work related to replacing the clutch or repairing the suspension, when the sensor could be affected.
Timely replacement of transmission fluid also helps extend the life of the sensors. Dirty liquid can corrode the contacts or clog the channels through which the signal is transmitted.
If you often drive off-road or in aggressive urban environments using reagents, it is recommended to additionally protect the sensor connector with a moisture-proof compound. This will prevent oxidation of the contacts.
If you experience the slightest signs of unstable speedometer operation or jerking when shifting gears, do not delay diagnostics. Catching the problem early will save you significant money on repairs.
Regularly check the integrity of the insulation of wires in the engine compartment, especially in places where there are bends and hot engine components, to prevent short circuits.
For owners Nissan with a variator (CVT) Any malfunctions in its operation can lead to overheating and failure of the belt drive.
| Parameter | Normal value | Fault value |
|---|---|---|
| Sensor resistance | 200–1000 Ohm | 0 Ohm or ∞ (open) |
| Supply voltage | 5–12 V | 0 V (no power) |
| Alarm when moving | Pulsating | Permanent or absent |
| Sensor temperature | Operating (up to 80°C) | Overheating or cold |
Do not forget that high-quality diagnostics require professional equipment. If you are not confident in your abilities, it is better to contact a specialized service that specializes in Japanese cars.
Regularly checking the wiring and promptly replacing the speed sensor is the key to preventing P1700 and extending the life of your Nissan transmission.
Specifics for various Nissan models
Although the principle of operation of the speed sensor is similar on all models, there are nuances in location and accessibility. On Nissan Qashqai and X-Trail With a CVT, the sensor is often located on top of the transmission, making it easier to access.
On models Nissan Teana and Maxima With classic automatic transmissions, the sensor may be built into the transmission control unit, which makes it difficult to replace and requires removal of the transmission in some cases.
For Nissan Patrol and Pathfinder With all-wheel drive, the system is more complicated, since there are speed sensors for the front and rear axles. The P1700 code could be related to any of these, requiring all circuits to be checked.
On Nissan Leaf and other electric vehicles, a similar error may indicate problems with the motor rotation sensors, which requires specialized high voltage diagnostics.
Owners Nissan Almera and Sentra It is worth paying attention to the condition of the connectors, since due to vibrations and cheap components, the contacts in them oxidize faster than on more expensive models.
FAQ: Frequently asked questions
Is it possible to drive with P1700?
Technically you can drive, but it is dangerous. The car will go into emergency mode, lose dynamics and may stall while driving. Long-term use is not recommended.
How much does it cost to replace a speed sensor on a Nissan?
The cost of the sensor itself varies from 1,500 to 5,000 rubles, depending on the model. Replacement work usually takes 30-60 minutes and costs from 1000 to 3000 rubles for service.
Is it possible to reset the P1700 error without a scanner?
Sometimes disconnecting the negative terminal of the battery for 10-15 minutes helps. However, if the cause of the malfunction is not eliminated, the error will return immediately after starting to drive.
Does P1700 affect fuel consumption?
Yes, significantly. Due to incorrect gear shifting, the engine operates at suboptimal speeds, which leads to excessive fuel consumption by 10-20%.
Where is the speed sensor located on the Nissan Qashqai?
On Nissan Qashqai with a variator, the sensor is located on the top of the transmission housing, closer to the engine, and is connected to a connector with a protective cap.
Remember that timely response to on-board computer signals is the key to long and reliable operation of your car. Don't ignore mistakes, even if they seem minor.