Nissan Sunny is a legendary car, known for its reliability, but even it is not immune to breakdowns. One of the most common problems is incorrect operation coolant temperature sensor (DTOZH). This small but critical element affects the operation of the engine, cooling fan and even fuel consumption. If your Sunny began to “lie” with temperature readings, stall at idle or overheat for no apparent reason - the sensor may be the culprit.
In this article we will not just show where is the temperature sensor on Nissan Sunny (models B14 and B15), but let’s also look at:
- 🔍 How to distinguish DTOZH from a temperature indicator sensor (they are different!)
- ⚠️ Signs of malfunction that are often confused with the thermostat
- 🛠️ Step-by-step replacement instructions with photos and nuances for Sunny
- 📊 Resistance table for checking with a multimeter
Important: the information is relevant for gasoline versions with engines GA14DE, GA15DE, GA16DE And SR20DE. For diesel Sunny (For example, CD20) the location and parameters of the sensors may vary.
Difference between temperature sensor and temperature gauge sensor
Many owners Nissan Sunny they confuse two different sensors that look similar, but perform completely different functions:
- 🔧 Coolant temperature sensor (DTOZH) - transmits data to Engine ECU to adjust the fuel mixture, ignition and fan operation. Located on in the cooling system inlet pipe near the thermostat.
- 📉 Temperature indicator sensor — is responsible only for the readings on the dashboard. Located in cylinder head (cylinder head) or on the upper radiator pipe (depending on the year of manufacture).
On Sunny B14 (1990–1995) both sensors are often located next to each other, but on B15 (1995–2000) they were demolished. If the temperature needle on the panel jumps, but the engine runs normally, the problem is in the pointer sensor. If the car stalls, has difficulty starting or consumes more fuel, the DTOZH is to blame.
- GA14DE/GA15DE (1.4–1.5 l)
- GA16DE (1.6 l)
- SR20DE (2.0 L)
- Diesel (CD20, etc.)
- I don't know
Where is the temperature sensor located on Nissan Sunny B14 And B15
The exact location depends on the model and year of manufacture, but the general layout is as follows:
| Model | Engine | Location of DTOZH | Photo/landmark |
|---|---|---|---|
| Sunny B14 (1990–1995) | GA14DE/GA15DE |
On the cooling system inlet pipe, next to the thermostat (battery side) | Under the plastic engine cover, next to the pipe tee |
| Sunny B15 (1995–2000) | GA16DE |
On the thermostat housing (upper part, closer to the radiator) | Often covered by the wiring harness, near the PCV valve |
| Sunny B15 (1998–2000) | SR20DE |
On the cylinder head (cylinder head), next to the 1st cylinder | Under the intake manifold, access is more difficult |
In practice, the easiest way to navigate is by thick black connector with two wires (usually gray and green). The temperature gauge sensor, on the other hand, has a single wire (usually white or yellow).
On Sunny B14 with air conditioning, the sensor may be hidden behind the compressor. To gain access, temporarily loosen the compressor and move it to the side (do not disconnect the hoses!).
If you are not sure which sensor is in front of you, remove the connector and check the number of contacts:
- 🔌 2 contacts — DTOZH (goes to the ECU)
- 🔌 1 contact — pointer sensor (goes to the instrument panel)
Signs of a malfunctioning temperature sensor on Nissan Sunny
A faulty DTOZh can manifest itself in different ways, but there is 5 Key Symptoms, which are often ignored, attributed to the thermostat or pump:
- ❄️ The engine takes a long time to warm up or does not reach operating temperature (especially in winter). The ECU “thinks” that the engine is cold and enriches the mixture.
- 🔥 Cooling fan does not turn on or works constantly. DTOZH can give false signals about overheating.
- 🚗 Floating idle speed (from 500 to 1500 rpm) after warming up. The ECU cannot adjust the fuel supply correctly.
- ⛽ Increased fuel consumption (1-2 liters more than usual). Associated with incorrect fuel/air ratio.
- 🔧 Error P0115 or P0116 (DTOZ circuit malfunction) on the scanner. But sometimes there are no errors, even if the sensor is lying!
Important: the same symptoms can cause thermostat, pump or air lock in the cooling system. Before replacing the sensor, check:
- Thermostat performance (it should open at 80–85°C).
- Level and quality of antifreeze (old or diluted antifreeze gives incorrect readings).
- The presence of air in the system (when warming up, feel the upper radiator pipe - if it is cold and the lower one is hot, there is a plug).
How to check the thermostat without removing it?
Start the cold engine and touch the upper radiator hose. It should remain cold until the temperature gauge rises to 80-85°C. If the pipe heats up immediately, the thermostat is stuck in the open position.
How to check the temperature sensor for Nissan Sunny multimeter
Checking the DTOZH takes 10 minutes and requires only a multimeter and a thermometer (you can use an infrared pyrometer or even a household thermometer). Algorithm:
- Remove the sensor (disconnect the connector, unscrew it with a 19 or 21 key).
- Immerse the working part into a container of water (for example, a kettle).
- Connect the multimeter in resistance measurement mode (20 kOhm) to the sensor contacts.
- Heat the water and record readings at different temperatures.
Compare results with reference values for Nissan Sunny:
| Temperature (°C) | Resistance (Ohm) for GA14DE/GA15DE | Resistance (Ohm) for SR20DE |
|---|---|---|
| 0 (ice water) | 4800–6500 | 5200–7000 |
| 20 (room) | 2300–3000 | 2500–3200 |
| 80 (working) | 270–380 | 300–400 |
| 100 (boiling) | 170–200 | 180–220 |
If resistance:
- 🔹 Above normal — the sensor “thinks” that the engine is colder than it actually is (the ECU enriches the mixture).
- 🔹 Below normal — the sensor shows false overheating (the fan runs constantly).
- 🔹 Doesn't change when heated, there is a break inside the sensor.
- 🔹 Shows 0 ohm - short circuit.
If the resistance of the sensor at 20°C is above 3500 Ohms or below 2000 Ohms, it needs to be replaced, even if there are no errors. ECU Nissan Sunny sensitive to deviations!
Step-by-step instructions for replacing the temperature sensor
Replacing DTOZH with Nissan Sunny - a simple procedure, but there are nuances that even experienced craftsmen miss. You will need:
- 🔧 Key for 19 or 21 (depending on the sensor model)
- 🛢️ New sensor (original number -
21022-4M000for GA14/15,21022-5M000for SR20) - 🧴 Thread sealant (for example, Loctite 577)
- 🧤 Gloves and rags (antifreeze is toxic!)
☑️ Preparation for replacing the DTOZH
Step 1: Drain the antifreeze
You don't have to drain all the antifreeze! Enough:
- Place a small container (0.5 l) under the sensor location.
- Unscrew the old sensor as quickly as possible and insert the new one.
- Add antifreeze to the level (through the expansion tank).
Step 2: Removing the old sensor
On Sunny B14 the sensor often “sticks” to the pipe. To avoid breaking the plastic:
- 🔧 Spray the threads with WD-40 and wait 5 minutes.
- 🔧 Use a socket wrench rather than an open-end wrench (less chance of tearing off the edges).
- 🔧 If the sensor doesn’t work, don’t pull it by force! Try screwing it back in a little and unscrewing it again.
Step 3: Install a new sensor
Important:
- 🔹 Apply a thin layer of sealant to the thread (but not to the working part!).
- 🔹 Tighten with force 15–20 Nm (do not overtighten!).
- 🔹 After installation, check for leaks (start the engine and warm up to operating temperature).
If after replacing the sensor with Sunny Check Engine light comes on, reset the error by disconnecting the battery for 10 minutes or using a scan tool. The ECU may “remember” old readings.
Common mistakes when replacing a sensor with Nissan Sunny
Even a simple operation can turn into problems if you do not take into account the features Sunny:
⚠️ Attention! On Sunny B15 with engine SR20DE The temperature sensor is located under the intake manifold. When replacing, it is easy to damage the manifold gasket if you do not remove it first (a torque wrench is required for reassembly!).
Other common mistakes:
- 🚫 Using non-original sensors. Cheap analogues (for example, from Febi or ERA) often give incorrect readings at low temperatures. Original sensor Nissan costs more, but will last longer.
- 🚫 Forgetting to reset ECU adaptations. After replacing the sensor with Sunny with
ECU Hitachi(installed on most B14s) long term fuel trims need to be reset. This can be done with a scanner or by disconnecting the battery for 30 minutes. - 🚫 Don't check the power supply. If the new sensor also does not work correctly, check:
- 🔹 The wires are broken (they often rub against the intake manifold).
- 🔹 Voltage on the connector (must be 5 V between “+” and ground).
On Sunny B14 with carburetor engine (GA14S) The temperature sensor only affects the fan. If the fan does not turn on, also check the relay and fuse F10 (10 A) in the block under the hood.
FAQ: Frequently asked questions about the temperature sensor Nissan Sunny
Is it possible to drive with a faulty DVT?
Technically possible, but not advisable. The ECU will use emergency temperature values (typically 80°C), which will result in:
- 🔹 Increased fuel consumption (by 10–15%).
- 🔹 Worsened dynamics (the engine becomes “stupid” when accelerating).
- 🔹 Risk of overheating (the fan may not turn on).
On Sunny B15 with SR20DE Ignoring the problem for a long time can lead to detonation and damage to the pistons.
Which temperature sensor is suitable for Nissan Sunny B14 1.4?
Original number - 21022-4M000. Analogues:
- 🔹 NGK NT301 (Japan, good quality).
- 🔹 Denso 550101 (original supplier for Nissan).
- 🔹 Bosch 0 280 130 017 (suitable, but may have an error of ±5°C).
Cost: original ~1500–2000 ₽, analogues ~800–1200 ₽.
Why does the temperature arrow on the panel not rise after replacing the sensor?
you replaced DTOZH, but the problem is temperature gauge sensor (one contact). It is located:
- 🔹 On Sunny B14 — in the upper radiator pipe.
- 🔹 On Sunny B15 — in the cylinder head (next to the 2nd cylinder).
Also check:
- 🔹 Fuse
F4(10 A) in the cabin unit. - 🔹 Integrity of the wire from the sensor to the instrument panel (often frays near the gas pedal).
How to reset P0116 after replacing the sensor?
On Nissan Sunny Error P0116 ("Invalid temperature sensor signal") is reset as follows:
- Disconnect the negative terminal of the battery for 10-15 minutes.
- Reconnect and start the engine.
- Warm up to operating temperature (the fan should turn on).
- Stop the engine and disconnect the battery again for 1 minute.
If the error returns, there is a problem in the circuit (open circuit, short circuit) or the new sensor is faulty.
Is it possible to clean an old temperature sensor?
No, it's pointless. DTOZH is thermistor, which changes resistance when heated. If it's broken, cleaning it won't help. The only thing you can do is:
- 🔹 Check the connector contacts (clean from oxidation).
- 🔹 Make sure that no oil or antifreeze gets on the sensor (this indicates a cylinder head gasket leak).