Resetting errors on Nissan Terrano Regulus: a complete guide with codes and instructions

Owners Nissan Terrano Regulus (known in Russia as Nissan Terrano II or Mistral) are often faced with the need to reset engine, ABS or other system errors. These errors can appear due to faulty sensors, bad fuel, electrical problems or after repairs. In most cases, you can reset errors yourself, without resorting to the help of a car service.

In this article we will look at all the current methods for resetting errors on Terrano Regulus (including models with engines TD27, TD27Ti, KA24E And SR20DE), we'll talk about the most common fault codes and give step-by-step instructions for different methods - from manual reset to using a scanner ELM327. You will also learn which errors can be ignored and which require immediate attention.

Why errors appear on Nissan Terrano Regulus and when they need to be reset

Electronic systems Terrano Regulus (especially models after 1995 with the system OBD-II) constantly monitor the operation of the engine, transmission, ABS and other components. If abnormalities are detected, memory ECU (electronic control unit) an error code is recorded and the indicator lights up on the dashboard CHECK ENGINE, ABS or 4WD.

The main causes of errors:

• 🔧 Sensor malfunctions (oxygen, crankshaft position, air flow, etc.).
• ⚡ Electrical problems: oxidized contacts, broken wiring, low battery voltage.
• ⛽ Bad fuel or clogged filtersleading to improper operation of the injectors.
• 🔥 Mechanical problems (for example, misfires, problems with the turbine on diesel versions).
• 🔄 Consequences of repair: if you changed spark plugs, high-voltage wires or sensors, but did not reset old errors.

Errors must be reset in the following cases:

• ✅ After eliminating the cause of the malfunction (for example, replacing the sensor).
• ✅ If the error appeared after refueling with bad fuel and disappeared after it was used up.
• ❌ Don't reset errors, if the cause is not eliminated, they will appear again, and in some cases this may worsen the problem (for example, if the catalyst is faulty).

⚠️ Attention: On diesel Terrano Regulus (especially with TD27Ti) frequent error resets without diagnostics can lead to failure EGR valve or turbines. If the error P0234 (excessive boost pressure) appears regularly - a check of the intercooler and turbocharger is required.

Common Nissan Terrano Regulus error codes and their interpretation

On Terrano Regulus found as universal OBD-II codes (starting with P0, P2), and specific for Nissan (For example, 0325 — malfunction of the knock sensor). Below is a table with the most common codes and their possible causes.

Error code	Description	Possible reasons	Is it possible to reset without repair?
P0100	Malfunction of the mass air flow sensor (MAF) circuit	The air flow sensor is dirty or faulty, the wiring is broken, the air filter is clogged	❌ No (diagnostics required)
P0300	Multiple misfires	Faulty spark plugs, high-voltage wires, coils, low compression	⚠️ You can reset, but the error will return without eliminating the cause
P0400	Exhaust gas recirculation (EGR) system malfunction	Clogged EGR valve, faulty solenoid, problems with vacuum hoses	❌ No (may cause engine overheating)
P0500	Speed sensor malfunction	Damaged sensor, broken wiring, problems with speedometer drive	✅ Can be reset after checking contacts
0325 (Nissan specific)	Knock sensor malfunction	Poor contact, damaged sensor, problems with the ECU	⚠️ Can be reset, but verification required

Critical errors that cannot be ignored: P0301-P0306 (misfire in a specific cylinder), P0234 (exceeding boost pressure on turbocharged diesel engines), P0420 (low catalyst efficiency). Resetting them without repair can lead to serious damage.

Methods for resetting errors on Nissan Terrano Regulus: from simple to complex

There are several methods for resetting errors, differing in complexity and required equipment. The choice of method depends on the year of manufacture of the car, the type of ECU and the available tools.

1. Reset errors by disconnecting the battery (for older models before 1998)

This is the simplest, but not always effective method. Suitable for Terrano Regulus with OBD-I (before 1996) or if it is not possible to use a scanner. Algorithm of actions:

1. Turn off the ignition and disconnect negative terminal battery
2. Press the brake pedal for 10-15 seconds (this will discharge the capacitors in the ECU).
3. Wait 15–20 minutes (at this time the ECU memory will be reset).
4. Reconnect the terminal and start the engine.

⚠️ Attention: On models with OBD-II (after 1996) this method may not work because errors are stored in non-volatile memory. In addition, after disconnecting the battery, the settings will be reset radio, hours and perhaps immobilizer (key retraining will be required).

2. Reset via on-board computer (for models with a panel display)

Some versions Terrano Regulus (For example, 1998–2000) were equipped with an on-board computer with an error reset function. Instructions:

1. Turn on the ignition (do not start the engine).
2. Press and hold the button TRIP RESET (reset daily mileage) for 10 seconds.
3. If the diagnostic menu appears on the display, select ERASE CODES or CLEAR DTC.
4. Confirm the reset (usually with a long press of the same button).

If the on-board computer does not support this function, try the combination:

1. Включите зажигание.
2. Нажмите и удерживайте кнопку сброса пробега.
3. Поворотом ключа включите зажигание (не заводите двигатель).
4. Удерживайте кнопку 10–15 секунд, пока не моргнёт CHECK ENGINE.

Check battery voltage (must be at least 12.4V)

Connect the scanner to the OBD2 connector (located under the steering wheel or in the glove compartment)

Turn on the ignition (do not start the engine)

Make sure the scanner has detected the communication protocol (ISO 9141 or KWP2000)

Save current error codes before resetting -->

3. Reset errors via OBD2 scanner (ELM327, ScanTool, etc.)

The most reliable and universal method, suitable for all models Terrano Regulus with OBD-II (1996 and newer). You will need:

• 📱 Scanner ELM327 (Wi-Fi or Bluetooth) or a specialized diagnostic tool (for example, Launch CReader).
• 📲 Smartphone/tablet with the program Torque Pro, OBD Auto Doctor or Nissan Consult.
• 🔌 Connector OBD-II (located under the steering wheel, sometimes hidden by a plastic plug).

Step by step instructions:

1. Connect the scanner to the connector OBD-II.
2. Turn on the ignition (do not start the engine).
3. Pair the scanner with your smartphone via Bluetooth/Wi-Fi.
4. Launch the program and select a function Reading Error Codes (DTC).
5. When the list of errors is displayed, select Erase codes (Clear DTC).
6. Confirm the action and wait for a message indicating a successful reset.
7. Turn off the ignition for 30 seconds, then start the engine and check if the errors appear again.

If the errors return, the problem is not resolved. For example, code P0171 (lean mixture) often indicates an air leak or faulty Mass air flow sensor.

What to do if the scanner does not connect?

If the scanner does not detect the ECU, check:

1. **Scanner power** - the indicator (usually red or green) should light up.

2. **Communication protocol** - for Nissan Terrano Regulus most often used ISO 9141-2 or KWP2000. In the program settings, select manual mode and go through the protocols.

3. **OBD-II connector condition** - oxidized contacts can block communication. Clean them with alcohol.

4. **Problems with the ECU** - if the scanner does not connect to any protocol, the control unit may be faulty (diagnostics at the service center is required).

Resetting ABS errors on Nissan Terrano Regulus

System errors ABS on Terrano Regulus (codes C11xx, C12xx) are reset separately from engine errors. Most often they arise due to:

• 🔄 ABS sensor malfunctions on wheels (breakage, pollution).
• ⚡ Wiring problems (frayed wires near the hubs).
• 🛠️ Low brake fluid level or faulty hydraulic unit ABS.

To reset ABS errors:

1. Check the brake fluid level and add if necessary.
2. Clean the ABS sensors from dirt (they are located next to the hubs).
3. Connect a scanner with support ABS (not all are cheap ELM327 know how to reset these errors).
4. Select a section in the program ABS → Clear DTC.
5. If the scanner does not see the ABS unit, try alternative method:

Alternative method (for models before 2000):

1. Выключите зажигание.
2. Нажмите и удерживайте педаль тормоза.
3. Включите зажигание (не заводите двигатель).
4. Удерживайте педаль 10–15 секунд, пока не погаснет лампа ABS.
5. Отпустите педаль и выключите зажигание.

⚠️ Attention: If after reset the lamp ABS lights up again when driving, don't ignore the problem - this can lead to brake failure on slippery roads. Most often, the sensors on the rear wheels are to blame (codes C1130, C1135).

Common problems when resetting errors and their solutions

Even with the right actions, owners Terrano Regulus encounter difficulties. Let's look at typical situations and ways to solve them.

Problem	Possible reason	Solution
Errors return after reset	The root cause has not been eliminated (for example, the sensor is faulty)	Carry out a full diagnosis or check the most likely components (spark plugs, mass air flow sensor, wiring)
The scanner does not see the ECU	Incompatible protocol, open circuit in K-line circuit, faulty ECU	Try another scanner or check the fuse ECU (usually 10A)
Lights up after reset CHECK ENGINE with new code	The reset resets the ECU adaptations, "learning" is required	Drive 10–15 km with smooth acceleration and braking
ABS errors do not reset	ABS unit is blocked or faulty	Try resetting via Nissan Consult or contact service

If the scanner shows an error U1000 (loss of connection with other units), check:

• 🔌 Fuses ECU, ABS, COM (located in the block under the hood).
• 🔧 Engine and body weight — oxidized contacts can block communication between blocks.
• 📡 CAN bus (for models after 2000) - break or short circuit in the wires CAN-H And CAN-L.

1. Turn on the ignition for 3 seconds.

2. Turn off the ignition for 10 seconds.

3. Repeat steps 1-2 2 more times.

4. Start the engine and let it idle for 5 minutes.-->

When resetting errors does not help: signs of serious malfunctions

Some errors on Nissan Terrano Regulus cannot be resolved with a simple reset - they indicate critical faults that require repair. Pay attention to the following symptoms:

• 🚨 The engine stalls or stalls (codes P0300-P0306) - there may be problems with ignition coils, injectors or compression.
• 💨 Black or blue smoke from the exhaust pipe (codes P0171, P0172) - faulty lambda probes, Mass air flow sensor or there is an air leak.
• 🔥 Engine overheating (code P0217) - check thermostat, pump And cooling fan.
• 🛑 Locking the gearbox in emergency mode (codes P0730-P0750) - problems with solenoids or automatic transmission valve body.

If after resetting the errors:

• 🔴 Lamp CHECK ENGINE lights up immediately after starting the engine - the problem is sensors or wiring.
• 🔴 The engine does not develop full power - problems with turbine (on diesel engines) or fuel pump.
• 🔴 New errors appear that were not there before - this may indicate ECU malfunction.

⚠️ Attention: On diesel Terrano Regulus with TD27Ti ignoring the error P0234 (exceeding boost pressure) can lead to turbine destruction and its fragments getting into the engine. If the error appears regularly, check vacuum hoses, intercooler And wastegate.

FAQ: Frequently asked questions about resetting errors on Nissan Terrano Regulus

Is it possible to reset errors on Terrano Regulus without a scanner?

Yes, on models before 1998, you can try a reset by disconnecting the battery or through the on-board computer (if it supports this function). However, on OBD-II cars (1996+) without a scanner, a reset is unlikely.

Why did the engine run worse after resetting the errors?

This is due to the fact that the ECU has reset adaptive settings (for example, fuel supply correction). To return to normal operation, you need to:

1. Drive 10–15 km at a leisurely pace.
2. Avoid sudden acceleration and braking.
3. Wait until the ECU “learns” again (usually takes 1–2 days).

Which errors can you reset yourself and which cannot?

Safe to reset:

• Errors related to bad fuel (P0171, P0172).
• Errors sensors, if you are sure that they are working properly (for example, P0130 — lambda probe).
• Errors ABS, if they appeared after replacing pads or discs.

Do not discard without repair:

• Errors misfires (P0300-P0306).
• Errors catalyst (P0420).
• Errors turbines (P0234, P0251).

Where is the OBD-II connector located on the Nissan Terrano Regulus?

On most models the connector is located:

• 🔌 Under the steering wheel (to the left of the column, sometimes closed with a plastic plug).
• 🔌 In the glove compartment (on some Japanese versions).
• 🔌 Behind the ashtray (rare, but found on early models).

If there is no connector, your car is equipped OBD-I, and for diagnostics you will need an adapter for 14-pin connector Nissan (located under the hood next to the ECU).

What should I do if the CHECK ENGINE lamp does not disappear after resetting the errors?

Possible reasons:

1. Error didn't reset (try another scanner).
2. Error constant (for example, open circuit of the sensor).
3. Problems with immobilizer (the lamp may be on due to key incompatibility).

Solution:

• Check with a scanner current errors (maybe new ones have appeared).
• If the error code starts with U (For example, U1000) - the problem is connections between blocks.
• On diesel models, check glow plugs (code P0380).