Temperature sensor <em>Nissan Sunny</em>: diagnostics, replacement and errors

Nissan Sunny - a legendary car, known for its reliability and ease of maintenance. However, even with such machines, critical elements fail over time, for example, coolant temperature sensor (DTOZH). This small device is responsible for the correct operation of the engine, influencing the composition of the fuel mixture, fan activation and even fuel consumption. If the sensor starts to “lie”, the consequences can range from increased engine appetite to overheating and serious breakdowns.

In this article we will look at how determine the DTO fault on Nissan Sunny (including models B13, B14, B15), where it is located, how to check it with a multimeter and replace it yourself. We will also consider typical errors (for example, P0115, P0116), which indicate problems with the sensor, and we will give advice on choosing original and analog spare parts.

Where is the temperature sensor located on Nissan Sunny?

In most versions Sunny (gasoline engines GA14DE, GA16DE, SR20DE) coolant temperature sensor installed in the thermostat housing or on the top of the cylinder block next to it. The exact location depends on the year of manufacture and modification:

• 🔧 Nissan Sunny B13 (1990–1995): DTOZH is located on cylinder head on the driver's side, next to the thermostat. Access to it is difficult due to the pipes.
• 🔧 Nissan Sunny B14/B15 (1995–2004): Sensor moved to thermostat housing (top or side), making replacement easy.
• 🔧 Diesel versions (CD20): DTOZH may be located on intake manifold or near the fuel pump.

To accurately identify the sensor, pay attention to its appearance: it is a small metal cylinder with a thread and a two-pin connector. Often installed nearby temperature gauge sensor (for the instrument panel), which looks similar but is connected to a different wiring harness. On Nissan Sunny B14 with engine GA16DE The DTOZh has a green connector, and the pointer sensor is gray.

Signs of a malfunctioning temperature sensor

A faulty DTOZ does not immediately reveal itself, but ignoring the symptoms is dangerous - this can lead to engine overheating or increased wear of parts. Basic “bells”:

• ⚠️ The revolutions are floating at idle speed (especially on a cold engine). The ECU receives incorrect data and adjusts the fuel mixture incorrectly.
• ⚠️ Cooling fan does not turn on or runs constantly, even when the engine is cold.
• ⚠️ Increased fuel consumption - due to the rich mixture that the ECU forms, “thinking” that the engine is cold.
• ⚠️ Check Engine with errors P0115 (DTOZh circuit malfunction), P0116 (signal outside the permissible range).
• ⚠️ The engine takes a long time to warm up or, conversely, it quickly overheats for no apparent reason.

On Nissan Sunny B13 with carburetor engines (GA14S) a faulty sensor can cause detonation due to incorrect ignition timing. In injection versions, the problem often manifests itself through jerks during acceleration and unstable operation at idle.

⚠️ Attention: If the temperature gauge arrow on the dashboard is at zero or goes off scale, the problem may not be in the DTOZH, but in temperature gauge sensor (separate device) or wiring. Check both sensors!

How to check a temperature sensor with a multimeter

Diagnosis of DTOZh takes 10–15 minutes and does not require special skills. You will need:

• 🔧 Multimeter (in ohmmeter mode).
• 🔧 Thermometer (preferably electronic).
• 🔧 Container with water (for example, a kettle).
• 🔧 Key for 19 or 21 (to remove the sensor).

Verification algorithm:

1. Remove the sensor from the machine (after draining part of the coolant or disconnecting the pipe to minimize losses).
2. Load the working part of the DTOZH into the water and start heating it, while simultaneously measuring the resistance between the sensor contacts and the temperature of the liquid.
3. Compare readings with reference values (see table below).

Temperature (°C)	Resistance (Ohm) for Nissan Sunny
0	4800–6500
20	2300–3000
40	1000–1300
80	270–380
100	170–200

If the resistance does not change when heated or the values deviate greatly from the norm, the sensor is faulty. Also check the circuit for an open circuit: with the connector disconnected, the resistance between the contacts should be 5–10 kOhm (at room temperature).

Step-by-step instructions for replacing DTOZH

Replacing the temperature sensor with Nissan Sunny - a simple procedure, but requires care. Main rule: do not allow dirt to enter the cooling system and don't lose the o-ring (if there is one).

Drain the coolant (or place a container under the pipe)|Disconnect the negative terminal from the battery|Prepare a new sensor and o-ring (if required)|Check for the presence of a 19 or 21 key (depending on the model)-->

Instructions:

1. Drain the antifreeze (to a level below the sensor) or disconnect the upper radiator pipe, clamping it to minimize losses.
2. Disconnect the connector from the sensor by pressing the latch.
3. Unscrew the sensor key. Be prepared for liquid to pour out of the hole.
4. Install a new sensor with the O-ring (if equipped) and tighten firmly 15–20 Nm (do not overtighten!).
5. Connect the connector and add antifreeze to the level. Warm up the engine and check for leaks.

On Nissan Sunny B14 with engine SR20DE the sensor may be “stuck” - in this case, use WD-40 or light blows with a hammer through a wooden spacer. Never force the sensor body as this may damage its internal structure.

What should I do if a leak appears after replacing the sensor?

If, after installing a new DTOZh, antifreeze oozes from under it, the reason may be:

1) Damaged O-ring (replace it).

2) Insufficient tightening (tighten the sensor with a force of 15–20 Nm).

3) Distortion during installation (remove the sensor and screw it in smoothly, without distortion).

If the leak persists, check the threads in the cylinder block - repairs may be required by cutting a new thread.

Original and similar sensors: articles and prices

For Nissan Sunny Both original sensors and analogues from trusted brands are suitable. The main thing is the match in resistance and thread. Below is a table with article numbers and approximate prices (for 2026):

Manufacturer	Article	Applicability	Price (₽)
Original (Nissan)	22630-4M000	Sunny B13/B14 (GA14DE, GA16DE)	1200–1800
Original (Nissan)	22630-5M000	Sunny B15 (SR20DE)	1500–2200
Bosch	0 280 130 019	Universal (fits most Sunny)	800–1200
Hella	6PT 009 103-041	Sunny B13/B14 (GA-series)	900–1400
Febi	22630	Analogue of the original for Sunny B15	700–1100

When choosing an analogue, pay attention to:

• 🔍 Thread type (usually M12x1.5 or M14x1.5).
• 🔍 Working part length - it must match the original.
• 🔍 Resistance at 20°C (should be between 2300–3000 Ohms).

⚠️ Attention: Cheap sensors without a brand (for example, from AliExpress) often have a nonlinear resistance characteristic, which leads to errors in the operation of the ECU. Savings of 300–500 rubles can result in problems with the engine.

Common replacement mistakes and how to avoid them

Even experienced car owners sometimes make mistakes when working with DTOZH. Here are the most common:

• 🔧 Using thread sealant. This can lead to its particles entering the cooling system and clogging the radiator. Correct: use only the original O-ring or fum tape (thin layer).
• 🔧 Sensor re-stretching. Excessive force will deform the housing or damage the threads in the block. Correct: tighten with a force of no more than 20 Nm.
• 🔧 Ignoring check after replacement. It is not enough to simply install a new sensor - you need to reset the ECU errors and check the operation of the system. Correct: After replacement, warm up the engine to operating temperature and make sure that the fan turns on on time.
• 🔧 Replacing only the sensor without checking the wiring. Oxidized contacts or damaged wires can simulate a DTOZh malfunction. Correct: Before replacing, check the circuit with a multimeter (the resistance between the connector contacts should be close to zero).

On Nissan Sunny B15 with engine SR20DE a problem often occurs when, after replacing the DTOZH cooling fan does not turn on. The reason is the additional fan relay, which can fail in parallel with the sensor. Check the relay (usually located in the fuse box under the hood).

FAQ: Frequently asked questions about the temperature sensor Nissan Sunny

Is it possible to drive with a faulty DVT?

In the short term, yes, but it is fraught with consequences. The ECU will use average data, which will lead to:

• Increased fuel consumption (up to 10–15%).
• Risk of engine overheating (if the fan does not turn on).
• Unstable operation at idle.

On Sunny B13 With a carburetor, a faulty sensor can cause detonation and damage to the pistons.

How to distinguish DTOZH from a temperature indicator sensor?

On Nissan Sunny Usually two sensors are installed:

• DTOZH (for ECU) - connected to a thick wiring harness, goes to the control unit.
• Pointer sensor (for the instrument panel) - connected to a thin harness, goes to the dashboard.

On B14/B15 DTOZH often has a green connector, and the pointer sensor is gray or black.

What coolant should I add after replacing the diesel engine?

For Nissan Sunny It is recommended to use ethylene glycol based antifreeze (green or blue) with approval Nissan Coolant L248 or analogues:

• CoolStream A-110 (green).
• Sintec Unlimited (red, compatible with L248).
• Original Nissan Long Life Coolant (original).

Do not mix antifreezes of different colors and manufacturers!

Why is the temperature not shown on the panel after replacing the sensor?

Probable reasons:

• you replaced DTOZH, and not the temperature indicator sensor (they are different!).
• The wire from the pointer sensor to the instrument panel is broken.
• The instrument panel itself is faulty (check the fuse F10 on Sunny B14).

Is it possible to clean the old DTOZH?

Mechanical cleaning (for example, with sandpaper) is useless - the fault lies in the internal thermistor. If the sensor is dirty on the outside (for example, due to antifreeze deposits), it can be washed in isopropyl alcohol, but this is a temporary measure. If there are signs of malfunction, it is better to replace the sensor.