Automatic transmission self-diagnosis <em>Nissan Terrano 1</em> (R20): how to identify faults without a scanner

Nissan Terrano 1 (internal designation R20) is a reliable SUV, but its automatic transmission (RE4R01A or RE4R03A) requires attention over time. If you notice jerks when switching, delays or slipping, do not rush to go to the service station. In 80% of cases, primary diagnosis can be carried out independently, using the built-in self-diagnosis system and simple tests.

In this article you will learn how to run self-diagnosis mode Automatic transmission Terrano 1, decipher error codes, check the oil level and identify common faults without expensive equipment. We'll also look at what symptoms to ignore. it's impossible - this can save the box from major repairs.

How to activate automatic transmission self-diagnosis mode on Nissan Terrano 1

B Nissan Terrano 1 (as with most models Nissan 90s) there is a hidden diagnostic mode that displays error codes through the blinking lamp OD OFF (or CHECK ENGINE, if a scanner is connected). To run it, follow these steps:

1. Make sure the engine is off and the key is in the OFF.
2. Press and hold the button OD OFF (located on the automatic transmission lever).
3. Turn the key to position ON (do not start the engine!).
4. After 2 seconds, release the button OD OFF — the lamp will start flashing.

Error codes are read by the number of long and short blinks. For example, 3 long + 5 short = error P0730 (incorrect gear ratio). If there are no errors, the lamp will light continuously for 5 seconds.

Deciphering error codes for automatic transmission Terrano 1 (RE4R01A/RE4R03A)

Error codes in Nissan Terrano 1 are divided into two groups: mechanical (related to wear of parts) and electronic (problems with sensors or solenoids). Below is a table of the most common codes and their possible causes.

Error code	Description	Possible reason	Recommendations
P0705	Selector lever position sensor malfunction	Oxidation of contacts, broken wiring, sensor failure	Check the sensor connector, clean the contacts
P0730	Wrong gear ratio	Worn clutches, valve body malfunction, low oil level	Check the oil, diagnose the valve body
P0740	Torque converter lock-up malfunction	Worn lockup clutch, faulty solenoid	Solenoid check, oil change
P0750	Shift solenoid malfunction	Solenoid contamination, open circuit, worn wiring	Cleaning solenoids or replacing
P0760	Pressure solenoid malfunction	Valve block clogged, solenoid worn	Flushing the valve body or replacing the solenoid

If you received the code P0730 or P0740, do not delay diagnosis - these mistakes often lead to accelerated wear of the clutches and gearbox repairs costing from 50,000 rubles.

⚠️ Attention: Codes P0705 And P0750 may appear due to oxidation of contacts in the connector TCM (automatic transmission control unit). Before replacing sensors, check the integrity of the wiring!

Checking the oil level and condition in the Terrano 1 automatic transmission

Low level or contaminated oil is the cause of 60% of malfunctions Automatic transmission in Nissan Terrano 1. The check must be carried out on a warm box (oil temperature 60–80°C). Algorithm:

Warm up the engine to operating temperature (10–15 minutes drive)

Place the car on a flat surface

Switch the selector through all positions (P-R-N-D-2-L) with a delay of 3 seconds

Remove the dipstick (located to the right of the engine, cylinder cap)

Wipe the dipstick, put it back in and take it out again-->

The oil level should be between the marks HOT (hot). If oil:

• 🔴 Below the minimum - top up Nissan Matic-D or an analogue (for example, Idemitsu ATF Type-J).
• 🟠 Dark with a burning smell — a complete oil change and flushing of the valve body is required.
• 🟢 Clean, but with metal shavings — wear of clutches or bearings (needs troubleshooting).

B Terrano 1 oil volume in automatic transmission - 8.5–9 liters (with complete replacement). For partial replacement, it is enough 3–4 liters.

Typical symptoms of automatic transmission malfunctions and their causes

Even without a scanner, you can identify problems by the behavior of the box. Below are the symptoms and their probable causes:

• 🚗 Jerks when shifting from 1st to 2nd gear - wear of clutch clutches K1, solenoid fault SL1.
• 🔄 Delay when downshifting - low oil pressure, dirty filter.
• 🔥 Slipping during acceleration — wear of the torque converter clutch or clutches.
• 🛑 Reverse gear does not engage - problem with the package B2 or solenoid SL4.
• ⚡ Shocks when shifting from 3rd to 4th — malfunction of the speed sensor or control unit.

If Terrano 1 does not move forward or backward, but the engine is running - most likely a problem has occurred open circuit between selector and gearbox or out of order torque converter.

⚠️ Attention: If after warming up the box starts to “kick” when cold, and then works normally, this is a sign friction wear. Ignoring the problem will lead to the destruction of steel disks and repairs from 80,000 rubles.

Diagnostics of solenoids and valve body without disassembly

Solenoids in Nissan Terrano 1 control oil flows and pressure in the valve body. Their malfunction manifests itself as:

• 🔧 Gear shift delays.
• 🔄 One of the gears does not turn on (for example, 4th).
• 💥 Hard impacts when switching.

You can check the solenoids without removing the valve body:

1. Remove the automatic transmission pan (after draining the oil).
2. Disconnect the valve body connector (located on the box body).
3. Measure the resistance of each solenoid with a multimeter (standard: 10–15 Ohm).
4. If resistance 0 ohm or ∞ - solenoid is faulty.

Also pay attention to the condition of the oil in the pan: if there is metal shavings or black residue, the valve body requires flushing or replacement.

How to wash the hydraulic unit without removing it from the box?

To wash the valve body without completely dismantling it, use a special cleaner (for example, Liqui Moly ATF Reiniger). Algorithm:

1. Drain the old oil.

2. Fill in the cleaner (1 can per 4–5 liters of oil).

3. Start the engine and let it idle for 10–15 minutes, switching the selector through all positions.

4. Drain the flushing fluid and fill with new oil.

⚠️ This method only helps with light contamination! If chips or sediment are present in large quantities, the hydraulic unit must be removed and cleaned with ultrasound.

When self-diagnosis is useless: signs of serious damage

Some malfunctions Automatic transmission Terrano 1 cannot be detected without disassembly or a professional scanner. Contact the service station if:

• 🚨 Box doesn't respond to selector (no forward/backward movement).
• 🔥 Comes out of the box strong burning smell (clutches burned out).
• 💧 There is a puddle under the car red oil (automatic transmission oil seal or radiator is destroyed).
• 🔧 Can be heard when moving metallic grinding (wear of bearings or gears).

In these cases, self-diagnosis will only confirm the presence of the problem, but will not help eliminate it. For example, if the box “goes into emergency mode” (lit CHECK AT and only 3rd gear is engaged), this may mean:

• 🔌 Open circuit of the input/output speed sensor.
• 🔧 Mechanical destruction of the planetary gear.
• 💻 Control unit malfunction (TCM).

Prevention of automatic transmission problems: 5 rules for Terrano 1 owners

To extend the life of your automatic transmission, follow these recommendations:

1. Change oil every 60,000 km (or once every 4 years if the mileage is low). Use only Nissan Matic-D or its certified analogues.
2. Warm up the box in winter before driving: after starting the engine, keep your foot on the brake and turn on all selector modes one by one (5 seconds each).
3. Avoid towing over a distance of more than 50 km - this leads to overheating of the oil and wear of the clutches.
4. Don't overload the car — Terrano 1 designed to tow a trailer up to 1.5 tons. Excess weight accelerates wear on the torque converter.
5. Keep an eye on the automatic transmission radiator — its contamination leads to overheating of the oil. Flush the radiator every 100,000 km.

If you buy Nissan Terrano 1 with mileage, be sure to check:

• 📝 Service history (availability of records of automatic transmission oil changes).
• 🔧 Oil condition (if it is black and smells of burning, the box is on the verge of being repaired).
• 🚗 Test drive behavior (jerking, slipping, delays are signs of wear).

Frequently asked questions (FAQ)

Is it possible to reset automatic transmission errors without a scanner?

Yes, in Nissan Terrano 1 errors are reset automatically after 50 ignition on/off cycles without reoccurrence of the fault. You can also reset errors manually:

1. Turn on the ignition (do not start the engine).
2. Press and hold the button OD OFF 10 seconds.
3. Release the button and turn off the ignition.

If the error appears again, the problem has not been resolved.

What kind of oil should I fill in the Terrano 1 automatic transmission?

Manufacturer recommends Nissan Matic-D (article KLE52-00004). Acceptable analogues:

• Idemitsu ATF Type-J
• Mobil ATF 3309
• Castrol Transmax J

⚠️ Do not use all-purpose oils (e.g. Dexron III) - this will lead to slipping of the clutches!

Why does the automatic transmission kick when cold?

Reasons:

1. Thickened oil (needs replacement).
2. Solenoid wear (does not hold pressure when cold).
3. Torque converter problems (lock-up clutch wear).

If the problem disappears after warming up, start by changing the oil and filter.

How much does it cost to repair a Terrano 1 automatic transmission?

The cost depends on the fault:

• Oil change + filter: 5 000–8 000 ₽.
• Valve block repair: 20 000–40 000 ₽.
• Replacing clutches: 50 000–80 000 ₽.
• Major renovation: 100 000–150 000 ₽.

Prices are relevant for Moscow and regional service stations (2026).

Is it possible to drive with P0730?

Short term - yes, but this will speed up the wear of the box. Error P0730 means that the gear ratio is not as expected, resulting in:

• Increased wear of friction clutches.
• Overheating of oil.
• Jerking and slipping.

It is recommended to carry out diagnosis within 1–2 weeks.