Error code P1122 on Nissan Primera P12: interpretation and solutions

Error P1122 on Nissan Primera P12 (2002–2007) is one of the most common problems faced by owners of this car. It is connected to the engine management system and often causes panic among drivers due to unstable engine operation, increased fuel consumption, or even refusal to start. Unlike obvious malfunctions such as a non-working light bulb, this code requires careful diagnosis, as it can indicate both minor failures and serious breakdowns.

In this article we will look at what exactly is hidden behind the error. P1122, what symptoms accompany it, and most importantly, how to independently identify and eliminate the cause. You will learn which sensors and components need to be checked first, what tools are needed for diagnostics, and when to turn to professionals. We will pay special attention to the nuances Primera P12 with engines QR20DE And QR25DE, since they have specific “weak points”.

If your car starts to feel “stupid” at idle, jerk when accelerating, or show Check Engine with code P1122 - do not rush to change expensive parts. In 70% of cases, the problem is solved by simple cleaning or replacing consumables. But for this you need to clearly understand the algorithm of actions.

What does error code P1122 mean on Nissan Primera P12?

Code P1122 in the system OBD-II stands for «Throttle Position Sensor (TPS) Circuit Intermittent Interruption» - intermittent open circuit of the throttle position sensor (TPDZ). Translated into simple language: engine control unit (ECU) records an unstable signal from the sensor, which is responsible for the throttle position. This is critical because ECU uses this data to calculate the fuel mixture and ignition timing.

On Primera P12 The throttle position sensor is integrated into the throttle assembly and is a potentiometer. Over time, its contacts wear out, oxidize or become dirty, resulting in “floating” readings. However, the error P1122 may appear for other reasons:

• 🔧 Malfunction of the TPS sensor itself (wear, mechanical damage).
• 🔌 Wiring problems: breaks, contact corrosion, poor ground.
• 💻 ECU malfunctions (rare, but possible during flashing or power surges).
• 🔥 Throttle assembly contamination (carbon deposits, oil deposits).
• ⚡ Unstable on-board voltage (for example, due to a discharged battery).

It is important to understand that P1122 - this is not a sentence. Most often it appears sporadically, especially in wet weather or during a cold start. But if you ignore it for a long time, it can lead to more serious problems: from increased wear of the catalyst to breakdown ECU.

Symptoms of error P1122: how to recognize it?

Error P1122 rarely comes alone. It is usually accompanied by noticeable changes in the behavior of the car. Here are the key signs that should alert you:

• ⚠️ Unstable idle speed: the engine “floats” at idle (from 500 to 1500 rpm).
• 🚗 Jerks during acceleration, especially at low and medium speeds.
• 🛑 Delayed response to the gas pedal (the so-called “turbojam”).
• 💨 Increased fuel consumption (10–20% higher than usual).
• 🔥 Check Engine Lights On and Off or stays on constantly.
• 🔄 Engine stalls when changing gears (on mechanics) or when stopping.

On Primera P12 with automatic transmission (AT) error P1122 may also appear jerking when changing gears, since ECU incorrectly calculates the load on the engine. В самых запущенных случаях автомобиль может переходить в emergency mode (Limp Mode), limiting the speed to 2000–2500 rpm.

If you notice at least 2-3 symptoms from the list, you should connect a diagnostic scanner and check for errors. Но даже если сканер показывает только P1122, это не значит, что проблема только в датчике. A comprehensive examination is needed.

⚠️ Attention! On Nissan Primera P12 with engine QR25DE error P1122 sometimes accompanied by code P0100 (неисправность цепи датчика массового расхода воздуха — Mass air flow sensor). Если у вас оба кода — начинайте диагностику с проверки Mass air flow sensor, так как он может «обманывать» ECU, вызывая ложные срабатывания P1122.

Step-by-step diagnosis of error P1122

To pinpoint the cause P1122, нужно пройти несколько этапов проверки. Начнём с самого простого и постепенно перейдём к более сложным шагам.

1. Проверка датчика положения дроссельной заслонки (ДПДЗ)

Sensor TPDZ on Primera P12 расположен на дроссельном узле. To check it you will need a multimeter. Algorithm of actions:

1. Remove the connector from the sensor (after turning off the ignition!).
2. Set the multimeter to resistance measurement mode (20 kOhm).
3. Measure the resistance between the contacts 1 and 2 (nutrition and weight) - should be 4–6 kOhm.
4. Measure the resistance between the contacts 1 and 3 (signal) when the damper is closed - 0.5–4.5 kOhm.
5. Smoothly open the damper manually and watch the readings: the resistance should increase evenly no jumps.

If the resistance “jumps” or is missing, the sensor is faulty and requires replacement. Также осмотрите контакты разъёма на предмет окисления или повреждений.

Отключить зажигание и снять разъём датчика|

Check resistance between pins 1 and 2 (4–6 kOhm)|

Check the resistance between pins 1 and 3 (0.5–4.5 kOhm with the damper closed)|

Убедиться в плавном изменении сопротивления при открытии заслонки|

Осмотреть контакты на окисление и повреждения-->

2. Checking wiring and connectors

Often the problem lies not in the sensor itself, but in the wiring. On Primera P12 wires to TPDZ go through a tourniquet, which can fray or get wet. What to do:

• 🔍 Inspect the wiring harness from the sensor to ECU for damage.
• 🔌 Check the “ground” of the throttle body (usually a bolt on the intake manifold).
• 💧 Убедитесь, что в разъёмы не попадает влага (особенно актуально после мойки).

If you find a break or corrosion, restore contact and insulate the problem area. Sometimes simply cleaning the contacts helps. WD-40 or contact cleaner.

3. Cleaning the throttle body

Carbon and oil deposits on the valve may interfere with normal operation. TPDZ. For cleaning you will need:

• Throttle body cleaner (eg LIQUI MOLY Pro-Line).
• A soft brush or lint-free cloth.
• Screwdriver for dismantling the assembly (if required).

Remove the throttle assembly (disconnect the pipes and unscrew the 4 bolts), then thoroughly clean the valve and channels. Do not use metal brushes - they will damage the special coating of the damper! After cleaning, be sure to throttle adaptation (more on this below).

4. Checking the on-board voltage

Unstable voltage (for example, due to a weak battery or faulty alternator) can cause false alarms P1122. Check:

• 🔋 The voltage on the battery when the engine is off should be 12.4–12.7 V.
• ⚡ Voltage when the engine is running - 13.8–14.4 V.
• 🔌 Condition of the “mass” of the engine and body.

If the voltage is below normal, charge the battery or check the generator.

Adaptation of the throttle valve after cleaning or replacing the TPS

After any manipulations with the throttle assembly (TPDZ, cleaning, replacement) to Nissan Primera P12 must be carried out damper adaptation. This is a "learning" procedure. ECU new parameters. Without it, the engine will work unstably, and the error P1122 may come back.

Adaptation algorithm:

1. Make sure the battery is fully charged (voltage is at least 12.5 V).
2. Turn the ignition on (without starting the engine) to 3 seconds.
3. Turn off the ignition 10 seconds.
4. Repeat steps 2–3 more 2 times (3 cycles in total).
5. Start the engine and let it idle 5–10 minutes without pressing the gas pedal.

If the adaptation was successful, the idle speed will stabilize, and the error P1122 will disappear. If not, repeat the procedure or check the quality of cleaning of the damper.

⚠️ Attention! On some versions Primera P12 with ECU Hitachi adaptation may require the use of a diagnostic scanner (e.g. Nissan Consult or Launch X431). If the manual procedure does not help, contact a diagnostician.

Replacing the throttle position sensor (TPS)

If diagnostics show that the sensor is faulty, it must be replaced. On Nissan Primera P12 Sensors with article numbers are installed:

Manufacturer	Article	Note	Price, rub.
Nissan (original)	22680-AL500	For engines QR20DE/QR25DE	3 500–4 200
Hitachi	TPS003	Similar to the original, good quality	2 800–3 300
Blue Print	ADT33303	Budget option, average quality	1 500–2 000
Febi	27316	Good reviews, suitable for P12	2 200–2 600

To replace you will need:

• New sensor TPDZ.
• Phillips head screwdriver.
• Socket wrench on 10 mm (to remove the throttle assembly, if necessary).

Procedure:

1. Disconnect the negative terminal of the battery.
2. Remove the connector from the sensor.
3. Unscrew the 2 sensor mounting bolts (usually a Phillips screwdriver).
4. Remove the old sensor and install the new one (make sure the damper is closed!).
5. Connect the connector and return the terminal to the battery.
6. Swipe throttle adaptation (see previous section).

Error after replacement P1122 must disappear. If not, check the wiring or ECU.

Additional causes of error P1122 and their solutions

If after replacing the sensor and cleaning the throttle the error P1122 continues to appear, the reasons may be more serious. Let's look at less obvious but possible problems.

1. Malfunction of the engine control unit (ECU)

In rare cases, an error P1122 occurs due to malfunctions ECU. This may happen after:

• 🔌 Incorrect disconnection of the battery (without removing the terminal while the engine is running).
• 💻 Unsuccessful flashing.
• ⚡ Moisture gets into the block.

To check ECU:

• Remove the unit (located under the glove compartment or behind the center console).
• Inspect the board for burnt elements or signs of corrosion.
• Check the voltage at the connector ECU (must match the diagram).

If the unit is faulty, it can be:

• 🔧 Repair (resolder damaged elements).
• 💻 Reflash (sometimes resetting adaptations helps).
• 🆕 Replace with a new or used one (original article number - 28490-AL500 for QR20DE/QR25DE).

⚠️ Attention! On Primera P12 with ECU Hitachi It is not recommended to install blocks from other models Nissan (for example, from Almera or X-Trail), even if they are externally identical. This can lead to incorrect engine operation and new errors.

2. Problems with the gas pedal (if an electronic throttle is installed)

On some versions Primera P12 (especially after 2005) was installed electronic throttle (ETCS). In this case the error P1122 may be related to:

• 🎛️ Malfunction of the gas pedal position sensor.
• 🔌 Broken wiring from pedal to ECU.
• 🛠️ Mechanical wear of the pedal.

For diagnostics:

1. Check the resistance of the gas pedal sensors (similar to TPDZ).
2. Inspect the connectors and wiring.
3. Make sure the pedal moves smoothly without sticking.

3. Problems with the fuel system

It would seem, what does fuel have to do with it? The point is that ECU calculates the composition of the mixture based on data from TPDZ, Mass air flow sensor and lambda probes. If, for example, injectors clogged or fuel pump faulty, the engine may be unstable and ECU will “think” that the problem is in the damper sensor.

What to check:

• 🔥 Fuel rail pressure (standard: 3–3.5 bar).
• 💦 Condition of the fuel filter (replace every 20–30 thousand km).
• 🔬 Performance of lambda probes (errors P0130–P0167).

How to check fuel rail pressure without a pressure gauge?

If you don’t have a pressure gauge at hand, you can use the “old-fashioned” method:

1. With the engine running, press the spool valve on the fuel rail (it looks like a nipple on a wheel).

2. If a strong stream of gasoline sprays out from under it, the pressure is normal.

3. If the stream is weak or absent, the problem is in the fuel pump or clogged filter.

⚠️ Be careful: gasoline under pressure may splash into your eyes!

When to turn to professionals?

Most causes of error P1122 on Nissan Primera P12 you can fix it yourself. However, there are situations when it is better to trust specialists:

• 🔧 If after replacement TPDZ, cleaning the throttle and adapting, the error remains.
• 💻 If you suspect a malfunction ECU (diagnostics on the stand is required).
• ⚡ If the error is accompanied by other codes (for example, P0300 — misfires).
• 🔥 If the engine goes into emergency mode and does not come out of it.
• 🛠️ If you have no experience working with car electronics (risk of damaging ECU).

The cost of diagnostics in the service is usually 1,000–2,500 rubles, and repair ECU - from 3,000 to 10,000 rubles, depending on the complexity. You can do it yourself by replacing sensors or cleaning the throttle, but if the problem is deep-rooted (for example, in the firmware of the unit), you cannot do without specialists.

When choosing a service, give preference to those who specialize in Nissan or Japanese cars. They have the necessary equipment (Nissan Consult III) and experience with Primera P12.

FAQ: Frequently asked questions about error P1122

Is it possible to drive with error code P1122?

Short term - yes, but not recommended. Driving for a long time with this error can lead to:

• Increased wear of the catalyst.
• Deterioration of dynamics and increased fuel consumption.
• The engine goes into emergency mode.

If the error appears rarely (for example, only during a cold start), you can postpone the repair, but it is better to eliminate the cause as soon as possible.

How to reset error P1122 without a scanner?

There are two ways:

1. Remove the battery terminal at 10–15 minutes (this will reset all errors, but will also erase adaptations, for example, windows and radio).
2. Carry out throttle adaptation (see section above) - sometimes the error disappears after this.

However, if the cause of the error is not resolved, it will appear again.

Is the TPS sensor from Nissan Almera suitable for Primera P12?

No, it won't do. Although the sensors may look the same externally, they have different calibrations and resistances. Installing the sensor from Almera (or another model) will lead to incorrect engine operation and new errors. Use only original spare parts or certified analogues for Primera P12.

Can P1122 be caused by bad gasoline?

No, it's an error P1122 It's related to the throttle position sensor, not the fuel. However, bad gasoline can:

• Clog the injectors, which will lead to unstable engine operation and indirect errors.
• Damage the catalytic converter causing other fault codes (eg P0420).

If problems arise after refueling, try draining the bad gasoline and refilling with high-quality fuel (for example, AI-95 from a proven gas station network).

How much does it cost to fix error P1122 in the service?

The cost depends on the reason:

Type of work	Price, rub.
Diagnostics	1 000–2 500
Cleaning the throttle body	1 500–2 500
Replacing TPS (with work)	3 000–5 000
ECU repair/replacement	5 000–15 000

Prices are indicated for Moscow and the Moscow region. In the regions, the cost may be 20–30% lower.