Error P1778 on Nissan Murano: what it means and how to fix it

Fault code P1778 on Nissan Murano is one of the most common transmission problems that often baffles owners. This error is related to the operation gear shift solenoid (Step Motor) and can manifest itself either as jerks when switching, or as a complete failure of the box to switch to certain speeds. Unlike many other codes, P1778 on Murano Z51 (2009–2014) and Z52 (2015–2021) often occurs due to simple contamination of the automatic transmission oil, but it cannot be ignored - this is a direct path to expensive repairs.

In this article we will analyze not only the standard causes of the error, but also hidden nuances, which are not mentioned in the official manuals. For example, why P1778 may appear after changing the oil in an automatic transmission or how this code is related to faulty transmission fluid temperature sensor. You will also find step-by-step instructions for self-diagnosis, a spare parts compatibility table and answers to frequently asked questions from owners Murano with a mileage of 150,000 km.

What does error code P1778 mean on Nissan Murano?

Code P1778 stands for "Step Motor Circuit Malfunction" — a malfunction in the gear shift motor (solenoid) circuit. This solenoid is responsible for smooth gear shifting in an automatic transmission. RE0F10A (installed on Murano Z50/Z51/Z52). When the transmission ECU detects an incorrect signal from the solenoid or a mechanical fault, it will activate automatic transmission emergency mode (usually blocks shifting above 3rd gear) and records an error.

Feature P1778 on Nissan Murano is that she can be like primary (independent malfunction of the solenoid), and secondary - a consequence of other problems:

• 🔧 Contamination or low oil level in automatic transmission (most often at mileage of 100,000+ km).
• ⚡ Wiring problems or oxidation of contacts on the solenoid connector.
• 🔥 Transmission overheating due to a faulty oil cooler.
• 🛠️ Mechanical wear the stepped motor itself or its gears.

Unlike the error P0730 (general transmission fault), P1778 always points to a specific element - solenoid Step Motor. However, diagnosing it only by code is not enough: for example, on 2012–2014 Murano this error is often accompanied P0740 (malfunction of the torque converter lock-up clutch), which complicates the search for the root cause.

Symptoms of error P1778: how they manifest themselves in practice

Error P1778 rarely occurs “out of the blue” - it is usually preceded by noticeable changes in the behavior of the automatic transmission. Here are the key signs to look out for:

• 🚗 Jerks when switching from 1st to 2nd or from 2nd to 3rd gear (especially when cold).
• ⚠️ "Check Engine" light comes on and/or indicator AT on the dashboard.
• 🔄 Automatic transmission freezes in one gear (usually on 3rd) and does not switch up/down.
• 🛑 Switching delays (up to 2–3 seconds) or slipping.
• 🔥 Extraneous sounds out of the box (grinding, humming) when driving.

On Nissan Murano Z51 (2009–2014) error P1778 is often accompanied by hard blows when switching to a lower gear (for example, when overtaking). On models Z52 (2015+) symptoms may be less pronounced - for example, it only lights up Check Engine, but there are no jerks. This is due to the modified firmware of the transmission ECU.

⚠️ Attention: If errors appear along with P1778 P0715 (input shaft sensor) or P0720 (output shaft sensor), this may indicate mechanical wear of plate couplings in automatic transmission. In this case, you will need to open the box.

Interesting fact: on Murano with a mileage of more than 200,000 km, error P1778 sometimes disappears after complete automatic transmission oil change with flushing, even if the solenoid is already worn out. This is due to the fact that fresh fluid temporarily restores the mobility of the gears of the stepped motor. However, the effect does not last long - after 500–1000 km the problem returns.

Causes of error P1778

To accurately determine the cause of P1778, you need to analyze not only the error code, but also car service history, mileage, as well as accompanying symptoms. Below is a complete list of possible causes, ranked by frequency of occurrence on Nissan Murano:

Reason	Frequency (%)	Characteristic signs
Contaminated oil in automatic transmission	45%	Jerks, the error appears after the oil warms up. The color of the liquid is dark, with a burning smell.
Step Motor Solenoid Malfunction	30%	Hard impacts when switching, the error is permanent (cannot be reset).
Wiring/connector problems	15%	The error appears periodically, depending on humidity or vibration.
Transmission ECU malfunction	7%	Multiple errors (P0700, P0730), the box is unstable.
Mechanical wear of automatic transmission	3%	Noise in the box, the error is accompanied by P0731–P0736 (gear faults).

On Murano Z50 (2003–2007) error P1778 is often associated with oxidation of contacts on the solenoid connector — due to their close location to the exhaust manifold, the wires overheat. On newer models (Z51/Z52) the main reason is oil contamination, since the manufacturer recommends replacing it every 90,000 km, but in practice the interval should be reduced to 60,000 km.

One more nuance: if an error appears immediately after changing the automatic transmission oil, it is likely that a non-original filter was used or the wrong type of fluid was used (for example, Dexron VI instead of Nissan Matic S). In this case, the solenoid may become stuck due to incompatible additives.

Diagnosing error P1778: step-by-step instructions

To accurately determine the cause of P1778, a comprehensive diagnosis will be required. Below is an algorithm of actions that will help narrow down the range of problems without disassembling the box.

Step 1: Read Errors

Use a scanner that supports the protocol OBD-II with advanced functions for automatic transmissions (for example, Launch X431 or Autel MaxiCOM). Important:

• 📋 Write it down all error codes, even if they seem unrelated to the transmission.
• 🔍 Check the settings Transmission Fluid Temperature (normal: 70–90°C).
• 📊 Remove the data log (Freeze Frame) - this will help you understand under what conditions the error appeared.

Step 2: Checking the automatic transmission oil

On Nissan Murano oil level is checked with the engine running and a heated box (liquid temperature 60–70°C). Use the original dipstick (on Z51/Z52 it is yellow). Please note:

• 🟢 Normal oil color: red or light brown.
• ⚠️ Critical sign: black color, metal shavings or burning smell.
• 🔧 If the oil is dirty, it is required complete replacement (not partial!) with washing.

Step 3: Step Motor Solenoid Test

The solenoid is located inside the box, but its connector is accessible without dismantling the automatic transmission. To check the circuit:

1. Disconnect the solenoid connector (located on the driver's side of the automatic transmission housing).
2. Measure the resistance between the connector contacts: standard for Murano — 10–14 Ohm.
3. Check the voltage at the connector with the ignition on: there should be 12 V.

If the resistance is below 8 ohms or above 16 ohms, the solenoid is bad. If there is no voltage, there is a problem in the wiring or the ECU.

⚠️ Attention: On Nissan Murano Z52 (2015+) solenoid Step Motor integrated into the valve block (valve body). Replacing it requires removing the automatic transmission pan and may require adapting the transmission through diagnostic equipment.

Step 4: Transmission ECU Check

If the solenoid and wiring are ok but the P1778 code remains, it may be faulty. automatic transmission control unit. Signs:

• 🔄 The error appears even after replacing the solenoid.
• 📉 The voltage at the solenoid connector “floats” (for example, 8–12 V instead of stable 12 V).
• 🚨 There are errors along with P1778 P0700, P0730, P0841.

On Murano The transmission ECU is located under the center console. It can only be checked by replacing it with a known good one or using a specialized tester (for example, Nissan Consult-III).

How to fix error P1778: repair methods

The repair method depends on the cause of the error. Below are step-by-step instructions for each case, from the simplest to the most complex.

1. Changing the automatic transmission oil

If the oil is dirty or its level is not correct, perform complete replacement (not partial!). For Nissan Murano you will need:

• 🛢️ 8–10 liters oils Nissan Matic S (original) or analogue (Idemitsu ATF Type-J).
• 🔧 New automatic transmission filter (Nissan 31726-31X00 or Beck Arnley 044-1010).
• 🛠️ Pan gasket (Nissan 31397-31X02).

Replacement algorithm:

1. Warm up the oil to 60–70°C (drive 10–15 km).
2. Drain the liquid through the plug on the pan, then remove the pan and replace the filter.
3. Wash the tray and magnets from metal shavings.
4. Fill in new oil through the filler neck (on Z51/Z52 it is located to the right of the engine).
5. Adapt the automatic transmission using a scanner (required!).

Cost of service work: 8,000–12,000 ₽ (excluding oil). Self-replacement will take 3-4 hours.

2. Replacing the Step Motor solenoid

If the diagnostics showed a faulty solenoid, it needs to be replaced. On Murano Z50/Z51 this can be done without removing the box:

• 🔧 Remove the automatic transmission pan and drain the oil.
• 🔍 Find the solenoid block (it is attached to the valve body).
• 🔄 Replace the solenoid Step Motor (original article number: Nissan 31340-31X00).
• 🔧 Install a new filter and pan gasket.

Cost of the original solenoid: 12,000–15,000 rubles. Analogs (for example, ATP Z-250) will cost 6,000–8,000 rubles, but their resource is lower.

⚠️ Attention: On Murano Z52 (2015+) solenoid Step Motor part of the valve block (valve body). Replacing it requires a special tool and setting the adaptive parameters of the automatic transmission. Without this, the box will not work correctly.

3. Repairing wiring or connector

If the problem is in the wiring, follow these steps:

• 🔍 Inspect the solenoid connector for oxidation or damage.
• 🔧 Clean contacts (use WD-40 Contact Cleaner).
• 📏 Check the integrity of the wires from the connector to the ECU (use a multimeter in the “test” mode).

A common problem on Murano Z50 — chafing of wires on the exhaust manifold bracket. In this case, you will need to insulate the wires with heat shrink tubing.

4. Replacing the transmission ECU

If the control unit is faulty, you can:

• 🔄 Replace with a new one (original: Nissan 28520-4M000, price: 40,000–50,000 ₽).
• 🔧 Repair (resolder capacitors or microcircuits).
• 📋 Reflash (if the error is caused by a software failure).

After replacing the ECU you will need automatic transmission adaptation using diagnostic equipment (Nissan Consult-III or Launch X431).

What happens if you don't fix P1778?

Ignoring error P1778 leads to accelerated wear of the friction discs, bearings and planetary gear of the automatic transmission. After 5,000–10,000 km, a major overhaul of the gearbox may be required (cost: 80,000–150,000 rubles).

Preventing error P1778 on Nissan Murano

To avoid recurrence of P1778, follow these guidelines:

• 🔧 Change the automatic transmission oil every 60,000 km (despite the official 90,000 km). Use only Nissan Matic S or Idemitsu ATF Type-J.
• ⚡ Check the oil level every 10,000 km (especially if there are leaks).
• 🔥 Monitor the automatic transmission temperature: If it exceeds 100°C, check the oil cooler.
• 🚗 Avoid aggressive driving (sharp starts, towing trailers) - this accelerates the wear of the solenoids.
• 🔍 Inspect connectors regularly on the box (especially after washing the engine).

On Murano Z52 (2015+) it is recommended to carry out every 100,000 km automatic transmission adaptation through diagnostic equipment. This allows you to reset accumulated adaptive learning errors and extend the life of the solenoids.

If your Murano frequently used in the city (traffic jams, short trips), reduce the oil change interval to 40,000–50,000 km. Under such conditions, the transmission fluid oxidizes faster and loses its properties.

Frequently asked questions about error P1778

Is it possible to drive with P1778?

Short-term - yes, but no more than 500–1000 km. Long-term driving with this error leads to accelerated wear of the friction discs and planetary gear. If the transmission goes into emergency mode (does not shift above 3rd gear), it is better to limit the speed to 80–90 km/h.

Will P1778 clear after an oil change?

If the reason was contaminated oil, yes, but not right away. After changing the fluid you need to:

1. Reset errors using the scanner.
2. Drive 50–100 km in gentle mode (without sudden acceleration).
3. Recount errors. If P1778 does not return, the problem is solved.

If the error remains, diagnostics of the solenoid or ECU is required.

How much does it cost to repair a P1778 in service?

The cost depends on the reason:

• Oil change + filter: 8,000–12,000 ₽ (labor) + 6,000–8,000 ₽ (oil).
• Step Motor Solenoid Replacement: 15,000–20,000 ₽ (work) + 6,000–15,000 ₽ (part).
• ECU repair/replacement: 20 000–40 000 ₽.
• Automatic transmission overhaul: 80 000–150 000 ₽.

On Murano Z52 (2015+) the cost is higher due to the need to adapt the box.

Can I replace the Step Motor Solenoid myself?

On Murano Z50/Z51 - yes, if you have experience working with automatic transmissions. You will need:

• Remove the box tray (you need a 10mm wrench and sealant for the gasket).
• Disconnect the solenoid block connector.
• Replace the faulty solenoid (they are secured with bolts or latches).
• Install a new filter and fill with oil.

On Z52 Self-replacement is not recommended - the solenoid is integrated into valve body, and special tools are needed to replace it.

What kind of oil should I put in my Murano automatic transmission to avoid P1778?

Only Nissan Matic S (original) or its 100% analogues:

• Idemitsu ATF Type-J (item: 30050011-770466).
• Ravenol ATF J1 Fluid (item: 4014835716118).

Do not use Dexron VI, Mercon LV or other universal oils - they are not compatible with solenoids RE0F10A.