Car owners Nissan Teana J32 often encounter an unpleasant situation when the Check Engine light comes on on the dashboard and the scanner issues a code P1722. This error is directly related to the transmission control system and indicates a malfunction in the speed sensor input signal. Ignoring the problem can lead to incorrect operation of the gearbox, kicks during shifting and, ultimately, to complete failure of the valve body.
System CVT (variator) on Teana J32 requires extreme accuracy in providing data on the speed of rotation of the shafts. If the electronic control unit (ECU) does not receive the correct signal from input speed sensor, it goes into emergency mode, limiting the vehicle's capabilities. For the owner, this means a loss of dynamics and the inability to operate the car normally.
What does code P1722 mean in the Nissan system?
Code P1722 stands for "Transmission Input Shaft Speed - Signal Too Low" or "Speed Sensor Circuit Open". In technical documentation Nissan this is interpreted as the absence of a signal or a signal that does not correspond to the real parameters of the vehicle’s movement. The ECU compares the data from the speed sensor and the readings from the crankshaft speed sensor. If the discrepancy is critical or the signal disappears, the system records an error.
On Nissan Teana J32 with engine 2.5 l or 3.5 l This problem occurs quite often due to the design features of the variator and the location of the sensors. The signal from the sensor is used not only to display speed on the speedometer, but also to control gear shift timing, system pressure and torque converter lock-up. Without this signal, the transmission becomes impossible to operate normally.
It is important to understand that the error P1722 can be either electrical or mechanical. Sometimes the problem lies in the sensor itself, and sometimes in the wiring or even in mechanical damage to the ring gear from which the pulses are read. The diagnostic process should begin by checking for the presence of the signal itself, and not just by replacing the part.
Main causes of malfunction
The list of reasons that cause signal failure ranges from simple contacts to complex mechanical failures. Most often the culprit is oneself speed sensor, which over time loses its magnetic properties or fails due to temperature changes. Another common cause is damage to the wiring harness leading to the CVT, especially around bends or moving parts.
A less obvious but possible cause is contamination of the sensor with metal shavings. Inside the variator Nissan Teana Natural wear and tear occurs, and small metal particles can settle on the magnetic head of the sensor, blocking the reading of pulses. In rare cases, the problem lies in the valve body or a faulty ECU, although this happens much less frequently.
The human factor should not be excluded. If work has previously been done on the transmission, the connector may have been poorly secured or the wire may have been pinched. Also, the error may occur when using non-original spare parts, the quality of which does not meet factory standards. Nissan.
- 🔌 Oxidation or broken contacts in the speed sensor connector.
- 🔩 Mechanical damage to the sensor housing or its magnetic element.
- ⚙️ Contamination of the sensitive element with metal shavings from the variator.
- 🔋 Problems with wiring: frayed insulation, short circuit to ground.
- 💻 Transmission control module (TCM) malfunction.
⚠️ Warning: Do not attempt to clear P1722 by simply disconnecting the battery terminal. If the reason is mechanical wear or lack of signal, the error will return instantly, and you will lose time for diagnosis.
Diagnostics and troubleshooting
The first step when an error occurs P1722 is to connect professional diagnostic equipment, such as Nissan Consult or a high-quality multi-brand scanner. It is necessary to check not only the presence of the code, but also look at the graphical dependence of the speed on Input Speed Sensor. If the graph remains a straight line at zero while the car is moving, this confirms the absence of a signal.
A visual inspection begins with checking the sensor connector. On Nissan Teana J32 it is located on the variator housing. You need to make sure that the connector is tightly seated, the contacts are not oxidized and have no signs of mechanical damage. This is followed by checking the wires from the sensor connector to the ECU connector for breaks or short circuits to the housing.
If the electrical part is working properly, the sensor must be replaced. However, before doing this, you should remove it and carefully inspect it for the presence of metal shavings. If there are chips, this is a sure sign that there is active wear inside the variator, and replacing one sensor will not solve the problem for a long time without cleaning the valve body.
- 🛠️ Check the resistance of the sensor: it must meet the technical specifications (usually in the range of 500-1500 Ohms).
- 📉 Compare the input speed sensor readings with the output speed on the scanner while driving.
- 🧹 Clean the sensor from chips, if any are found, and assess the degree of contamination.
- 🔍 Inspect the wiring for signs of overheating or mechanical damage.
- Do it yourself with a multimeter
- In the service on the scanner
- Based on symptoms without diagnosis
- Not diagnosed yet
⚠️ Attention: If you find a large amount of chips when removing the sensor, be sure to rinse the magnets and clean the variator housing, otherwise the new sensor will quickly fail.
Step-by-step instructions for replacing the speed sensor
Replacement input speed sensor on Nissan Teana J32 - The procedure is relatively simple, but requires care. It is better to carry out work on a lift or inspection pit. You will need a set of wrenches, a new original sensor, a rag and possibly contact cleaner.
First you need to remove the engine protection (if it blocks access to the gearbox). Next, find the speed sensor connector, disconnect it and unscrew the fixing bolt. The sensor is removed carefully, without using excessive force, so as not to damage the seat. A new one is installed in place of the old sensor, but be sure to use a new gasket or copper ring, if provided for by the design.
After installing the new element, you need to connect the connector, make sure it is fixed and start the engine. Then you need to drive the car to check if the error has disappeared. If the scanner shows that the data is being received correctly, you can reset the adaptations and complete the job.
☑️ Instructions for replacing the sensor
This is done through the diagnostic scanner by resetting pressure adaptations and learning the neutral point. Without this procedure, the box may operate jerkily even with a working sensor.
What to do if the error returns immediately?|If the P1722 error returns immediately after replacing the sensor, check the integrity of the wiring harness to the ECU. Perhaps the break is inside the harness that runs through the body. Also check whether the ECU itself is not filled with liquid or whether the contacts inside it are oxidized. In rare cases, the control unit itself may need to be replaced.-->
Wiring and contact problems
One of the most insidious causes of error P1722 there is a problem with the wiring. Wiring harness on Nissan Teana passes near hot engine and suspension components. Over time, the insulation can fray, resulting in a short circuit or open circuit. Particularly vulnerable are the places where the wire enters the connector and the areas running next to the suspension arms.
To check you need to use a multimeter. Measure voltage and resistance at each section of the circuit. Pay attention to the color of the wires
at Nissan they often have specific color markings that are easy to confuse. Find the wiring diagram for your specific model year as wire colors may vary.
If a break is detected, the wire must not just be twisted and wrapped with electrical tape, but properly soldered and insulated with heat shrink. Vibration in the engine compartment will quickly destroy the weak twist, and the problem will return. Also check the grounding: poor ground contact can cause false alarms of the sensor.
Sometimes the problem is oxidation of the contacts inside the sensor connector itself. Moisture and dirt can create an insulating layer that prevents signal transmission. In this case, it is enough to clean the contacts with a special aerosol and treat them with contact lubricant.
High-quality wiring repairs require soldering and heat shrinking, and not just twisting, since vibrations in the car will quickly destroy unreliable contact.
Effect of a malfunction on the operation of the variator
Electronic control unit CVT completely depends on the speed sensor data. Without the correct input shaft speed signal, the system cannot determine which mode the transmission is operating in. This causes the ECU to be unable to calculate the required oil pressure to secure the pulleys, causing the belt to slip.
When driving for a long time with an error P1722 the variator goes into emergency mode. In this mode, the transmission is fixed in one gear (usually second or third), and no shifts occur. The engine can run at high speeds, but the vehicle speed will be low. This is a protective mechanism that prevents complete failure of the variator.
Constant slipping or running in emergency mode with incorrect pressures leads to overheating of the transmission fluid. The overheated liquid loses its properties, and active wear of the bearings, gears and the belt itself begins. The result of such neglect is expensive repairs or complete replacement of the unit.
| Parameter | Normal value | Meaning for error P1722 | Consequences |
|---|---|---|---|
| Speed signal | Proportional to rpm | Missing or 0 | Shift lock |
| System pressure | Dynamic regulation | Maximum or minimum | Belt slippage |
| Operating mode | Normal | Emergency (Limp Mode) | Loss of dynamics |
| Oil temperature | 80-90°C | >110°C | Liquid degradation |
⚠️ Attention: Operating a vehicle with the Check Engine light on and error code P1722 is strictly not recommended. The risk of overhauling the variator increases significantly with every hundred kilometers traveled.
Prevention and Maintenance
To avoid the error P1722, it is necessary to comply with the maintenance regulations Nissan Teana J32. The main rule is to regularly change the transmission fluid. The old liquid loses its cleaning properties, and metal shavings begin to settle on the sensors and magnets.
It is recommended to carry out a partial oil change every 30-40 thousand kilometers. It is also worth periodically checking the condition of the speed sensor connector, especially if the car is operated in conditions with high humidity or frequent temperature changes. Simply cleaning the contacts can prevent serious damage.
Use only original consumables and sensors. Cheap analogues often have incorrect magnetic characteristics or poor quality of wire insulation, which leads to rapid failure. Investing in a quality original sensor will save you money on future CVT repairs.
- 🛢️ Change the transmission fluid every 40,000 km.
- 🔍 Inspect sensor connectors annually for oxidation.
- 🛡️ Use only original speed sensors from Nissan.
- 🌡️ Monitor the operating temperature of the variator, do not allow it to overheat.
Regularly changing the transmission fluid is the most effective way to prevent metal shavings from contaminating the sensors and causing the P1722 code to appear.
Frequently asked questions (FAQ)
Is it possible to drive a Nissan Teana J32 with error P1722?
Technically, the car will continue to move, but will go into emergency mode with limited speed and dynamics. However, operation in this mode is extremely dangerous for the variator, as this can lead to its complete failure due to incorrect oil pressure and overheating. It is better to stop driving and call a tow truck.
How much does it cost to replace a speed sensor on a Teana J32?
The cost of an original speed sensor varies depending on the supplier, but usually ranges from 3,000 to 6,000 rubles. Replacement work at the service center will cost an additional 1,500-3,000 rubles, since access to the sensor requires removing the protection and sometimes other elements of the engine compartment.
Is it possible to clean the sensor from chips instead of replacing it?
Yes, if the sensor is not physically damaged and its magnetic properties are not impaired, it can be cleaned of metal shavings and reinstalled. However, if the error returns immediately after cleaning, this indicates that the sensor is faulty or there is active wear inside the variator, requiring deeper repairs.
Do I need to do an adaptation after replacing the sensor?
Yes, after replacing the speed sensor, it is recommended to carry out the variator adaptation procedure through a diagnostic scanner. This will clear old errors and allow the control unit to relearn the transmission operating parameters with a new sensor, which will ensure smooth shifts.
How to distinguish an original sensor from a fake?
Original sensor Nissan has clear markings, high-quality packaging and even wire insulation. Counterfeits often have uneven body molding, blurry lettering and cheaper wiring material. It is recommended to purchase spare parts from authorized dealers or trusted suppliers with a guarantee.