A transmission problem is one of the most unpleasant scenarios for a crossover owner. Nissan Murano second generation, known as the Z50. When the indicator on the dashboard comes on Check Engine, and the on-board computer issues a code P1700, this indicates a critical failure in the automatic transmission control system (ATC). Most often, owners encounter this problem over 150 thousand kilometers, when transmission components begin to require attention.
Code P1700 In Nissan technical documentation, it stands for “Vehicle Speed Sensor “A” Circuit.” This is not just a warning, but a signal that the transmission control unit (TCM) has stopped receiving correct data on the speed of rotation of the transmission output shaft. Without this information, the ECU cannot change gears correctly, which leads to sudden jerks, kicks when shifting, or going into emergency mode with one gear locked.
It is important to understand that the P1700 error on the Z50 platform rarely occurs on its own for no apparent reason. This is either a physical breakdown of the sensor, or, what is even more common, a break or short circuit in the wiring. Ignoring the problem can lead to overheating of the torque converter and failure of the friction discs, so diagnostics should be carried out as soon as possible.
The essence of the problem: What is hidden behind the P1700 code
Control system CVT or a classic 5-speed automatic transmission Nissan Murano Z50 critically depends on accurate speed data. The Vehicle Speed Sensor (VSS) generates electrical pulses proportional to the speed of rotation of the output shaft. These signals are sent to the TCM, which, based on them, calculates the gear shift moment and pressure in the valve body.
If the signal is interrupted or distorted, the control unit loses control over the process. As a result, you may notice that the car stops picking up speed above a certain threshold, or the transmission “thinks” before upshifting. In the worst case scenario, the transmission locks in emergency mode, usually in 3rd gear, making further movement extremely difficult.
Why P1700? Unlike errors related to oil pressure or solenoids, P1700 indicates a problem in the input data. This means that the mechanics of the box itself may be working properly, but the “brains” do not see how it works. This is why many owners try to replace expensive automatic transmission parts without finding the real culprit - the wiring or connector.Main causes of malfunction
The most common code culprit P1700 on Nissan Murano Z50 is a failure of the speed sensor itself. Over time, the seal of the housing is broken, oil or moisture gets inside, which leads to corrosion of the contacts inside the element. Also, the magnetic element or sensor coil may simply stop working.
The second, and perhaps the most insidious reason is the condition of the wiring. The Murano engine compartment is hot and constantly vibrating. The insulation of the wires going from the sensor to the TCM unit becomes dull and cracks over time. This leads to an open circuit or short to ground. Often the problem lies in the connector: the contacts oxidize due to moisture or antifreeze, creating a high contact resistance.
Another reason that is often forgotten is problems with the TCM control unit itself. In rare cases, when the wiring and sensor are working properly, the failure occurs inside the electronic unit. This may be caused by a voltage surge in the on-board network or an internal defect in the microcircuit responsible for processing speed sensor signals.
- 💥 Physical damage to the case speed sensor due to mechanical stress.
- 🔌 Oxidation of contacts in the sensor connector or in the TCM unit.
- 🐭 Damage to wiring insulation by rodents or due to vibration.
- 🔋 Malfunction of the transmission control unit (rare).
Diagnostics and testing of the electrical circuit
Before purchasing a new sensor, it is necessary to conduct a thorough diagnosis. You will need a multimeter and a wiring diagram to Nissan Murano Z50. Start by visually inspecting the wiring harness coming from the speed sensor located on the transmission housing. Look for obvious signs of friction, melting or chafing of the insulation.
Next, you need to check the resistance of the sensor itself. Disconnect the connector and measure the resistance between the sensor terminals. Normal values are usually in the range of 200 to 500 ohms, but the exact figures should be checked with the technical manual for your year of manufacture. If the multimeter shows “infinity” (open) or zero (short), the sensor is clearly faulty.
Checking the circuit for opens and short circuits is carried out by testing the wires from the sensor connector to the TCM connector. This is painstaking work that requires accuracy. If you find a break in the circuit, it must be repaired using high-quality soldering and heat shrinking, and not just twisting, which will quickly oxidize.
- Less than 100,000 km
- 100,000 - 200,000 km
- More than 200,000 km
- I don't know for sure
Step-by-step instructions for replacing the sensor
If diagnostics have confirmed that the sensor is faulty, replacing it is not very difficult for a car enthusiast with minimal skills. The sensor is located on the side of the gearbox housing; it is convenient to approach it from below the car or from above by removing the battery compartment.
First you need to ensure safe access to the work area. Raise the car on a lift or place it on secure stands. Open the hood and, if necessary, remove the battery and battery tray to gain a full view of the top of the transmission.
The replacement process is as follows:
1. Disconnect the electrical connector by pressing the latch.
2. Unscrew the sensor mounting bolt (usually a 10 or 12 mm bolt).
3. Carefully remove the old sensor, without using excessive force, so as not to damage the seat.
4. Install a new sensor, first checking the condition of the O-ring.
5. Tighten the bolt and connect the connector.
☑️ Preparing to replace the sensor
What to do if the sensor is stuck?
If the sensor is stuck, do not try to unscrew it sharply so as not to break the housing. Use a penetrating lubricant (WD-40) and let it sit for 15-20 minutes. You can carefully pry the sensor off with a mounting spudger, but be extremely careful not to damage the box body.
After installing a new component, be sure to reset the error using the diagnostic scanner. Start the engine and let it idle, then drive a short test route to check the transmission in different modes.
Restoration of wiring and contacts
In cases where the sensor itself is working, the problem often lies in the wiring “braid”. On Nissan Murano Z50 The wires going to the speed sensor pass close to hot engine components and the exhaust system, which accelerates their aging. If you see that the insulation is cracked and the copper strands are visible, this is a direct threat of a short circuit.
When restoring a circuit, it is strictly not recommended to use adhesive tape or electrical tape as the main method of protection. The best solution is to solder the damaged area and then insulate it with heat shrink tubing. If the wire is completely frayed, it must be replaced with one of a similar cross-section and insulation quality.
Pay special attention to the connectors. Oxidized contacts must be cleaned with fine sandpaper or a special brush, and then treated with contact fluid. If the sockets in the connector become bent and the contact becomes unreliable, they must be carefully tightened or the entire connector must be replaced using heat-shrink sleeves to connect the wires.
Before starting electrical work, be sure to disconnect the negative terminal of the battery to avoid accidental short circuit and damage to the TCM.
Checking and adaptation after repair
After all work to replace the sensor or restore the wiring is completed, you need to make sure that the error P1700 completely eliminated. To do this, connect the diagnostic scanner to the OBD-II connector. If the code does not disappear immediately after resetting, it means that the problem remains or an error was made during installation.
An important step is to check the signals in real time. In the diagnostic scanner menu, find the vehicle speed sensor data parameters. When the car is moving, the speed value should change smoothly, without jerks or breaks. If the speed on the scanner “jumps” or shows zero when moving, then the problem has not been solved.
Sometimes, after eliminating the cause, it may be necessary to adapt the gearbox. This is not always necessary to resolve P1700, but is helpful in restoring smooth shifting. The adaptation procedure usually involves warming up the transmission, driving in various modes (D, R) and cyclically changing gears.
Successful replacement of the sensor and restoration of the wiring should lead to the disappearance of error P1700 and normalization of automatic transmission operation without the need for complex flashing of the unit.
Comparison of repair options and costs
Owners Nissan Murano Z50 Often faced with a dilemma: change only the sensor or change the entire wiring harness at once. If the problem is simply caused by wear of one element, replacing the sensor is the most cost-effective option. However, if the wiring is in critical condition, the savings may result in repeated repairs in a couple of months.
Let's look at the approximate cost of work and spare parts in the table below. Prices may vary depending on the region and the chosen service, but the order of the numbers will help you navigate your budget.
| Type of work / Spare part | Estimated cost (RUB) | Complexity of work |
|---|---|---|
| Speed sensor (original) | 3 500 — 6 000 | Low |
| Speed sensor (analog) | 1 500 — 2 500 | Low |
| Wiring harness (new) | 8 000 — 12 000 | Average |
| Sensor replacement work | 1 500 — 3 000 | Low |
| Wiring repair (complicated) | 3 000 — 7 000 | High |
The choice between the original and the analogue also plays a role. Original sensors Nissan They last longer and transmit signals more accurately, but are much more expensive. High-quality analogues from trusted brands can be an excellent compromise if the budget is limited. The main thing is to avoid cheap fakes of unknown origin.
Prevention and expert advice
To avoid the code appearing again P1700, it is necessary to regularly inspect the engine compartment. Pay attention to the condition of all wires, especially those running near hot parts. If you notice scuffs or cracks in the insulation, take immediate action to eliminate them.
One of the important points is monitoring the level and quality of oil in the gearbox. Although P1700 is an electrical code, dirty or old oil can interfere with the torque converter and create vibrations that can accelerate wiring wear. Regular oil and filter changes will extend the life of the transmission and its electronic components.
If you are planning a long distance trip, make sure that the speed sensor problem is completely resolved. Driving with a faulty sensor can cause your vehicle to behave erratically on the highway, creating a safety hazard for you and others.
How to distinguish P1700 from other automatic transmission errors?
Error P1700 is specific to the speed sensor. Errors P1701, P1702, P1703 are often associated with pressure control solenoids or torque converter lockup. If you see other codes on the scanner screen, the diagnosis will be fundamentally different.
When purchasing a used Nissan Murano Z50, be sure to check the service history and any errors in the TCM memory. The P1700 code may be hidden if the seller simply cleared the errors before selling.
⚠️ Attention: Don't ignore the Check Engine Light! If the P1700 code appears intermittently, this is a sure sign that the circuit is unstable and could break completely at any time.
⚠️ Attention: When replacing the sensor, use only a high-quality sealant. Even a microscopic gap can allow oil to get inside the connector and quickly cause the new sensor to fail.
⚠️ Attention: The most critical mistake during repair is trying to solder the connector without replacing the oxidized contacts. This will create a false contact, which will disappear at the first vibration, and the problem will return.
Frequently asked questions (FAQ)
Is it possible to drive with P1700?
Technically you can drive, but it is dangerous and harmful to the box. The car may go into limp mode, lose power, and not respond to the gas pedal the way you are used to. This creates a risk of an emergency, especially when overtaking or driving in traffic.
How much does it cost to repair wiring at a service center?
The cost of wiring repair depends on the difficulty of access and the length of the damaged section. On average, work to restore a speed sensor harness costs from 3,000 rubles, but if a complete replacement of the harness is required, the price can rise to 10-15 thousand rubles, taking into account spare parts.
Does resetting the error without repair help?
No, resetting the error through a scanner without eliminating the cause only gives a temporary effect. As soon as the control unit receives an incorrect signal again, the error will return. It is a diagnostic tool, not a treatment tool.
How often does the speed sensor on a Murano Z50 fail?
This is one of the common problems on runs over 150,000 km. With timely diagnosis and replacement of consumables, the problem is solved quickly and inexpensively, without affecting expensive transmission components.