Mitsubishi Lancer IX - a legendary car that still remains popular among motorists due to its reliability and maintainability. But even these machines have weaknesses, and one of them is: idler. This small detail is responsible for the stable operation of the engine at idle speeds, and its malfunction can cause a lot of trouble: from floating revolutions to a complete stop of the engine.

In this article, we will discuss what is RX in Lancer 9How it is arranged, what signs indicate its failure, and how to independently check and replace the regulator. We'll pay special attention. Common errors in diagnosisThis often leads to unnecessary spending of money on replacing the correct parts. If you Lancer 9 began to stall at idle or the turns “walk” for no apparent reason – this instruction will help to understand the problem without contacting the service.

What is RX and how does it work in Mitsubishi Lancer 9?

The idle regulator (RXX), aka Idling Air Control Valve (IACV)It is an electromechanical device that controls the air supply bypassing the throttle. Its main task is to maintain stable engine speeds when the gas pedal is not pressed (for example, at traffic lights or when warming up). V Lancer 9 motorized 4G18 (1.6 l) and 4G94 (2.0 L) RX plays a key role in the engine control system, as it directly affects the composition of the fuel-air mixture.

Structurally, the regulator is a stepping electric motor with a cone needle. When the engine control unit (CD)ECU) detects a fall in revolutions below normal, it sends a signal to the RX, and it opens the bypass channel, allowing additional air to pass. Thus, the turnovers are stabilized. V Lancer 9 RX is integrated into the throttle assembly body and connected to ECU through a connector with 4 contacts.

It is important to understand that RXX is actuatorNot a sensor. He doesn't send data to ECUHe just keeps his commands. Therefore, in the diagnosis of malfunctions The RX test should be carried out in conjunction with the testing of the throttle, crankshaft position sensor and ignition system Often the symptoms of their breakdowns coincide.

  • 🔧 Where is RXX in Lancer 9: on the throttle assembly, next to the throttle position sensor (TPS). He's got two screws under the screwdriver.
  • ⚡ Principle of work: The stepper motor moves the needle, adjusting the cross section of the bypass channel. The more the channel is open, the higher the idling turns.
  • 📊 Nominal turnovers XX: for 4G18 750–850 rpm, for 4G94 - 650-750 rpm (with the engine warmed up).
📊 What engine is installed in your Lancer 9?
4G18 (1.6 l)
4G94 (2.0 l)
4G63 (2.4 l)
Other
I don't know.

Signs of malfunction of the RXX on the Mitsubishi Lancer 9

A faulty idle regulator manifests itself as clear symptoms that are difficult to confuse with other problems. However, many car owners mistakenly write them off. air mass flow sensor (MADR) or throttle. To avoid spending money on unnecessary details, pay attention to the following signs:

1. Floating velocities idling. The turns spontaneously rise to 1500-2000 rpm, then fall to 500-600, sometimes the engine stalls. This is the most common symptom that indicates needle-jamming Or a break in the windings of a stepping motor.

2. The engine will stop when the gas is discharged. For example, when braking or changing gears. This is because the RX does not have time to compensate for the drop in revs, and the engine “choked” from lack of air.

3. Difficult launch "cold". With faulty RX ECU cannot properly adjust the speed during warming up, because of which the engine starts from the third to fifth attempt or requires a gaze.

4. Increased turnovers of XX (more than 1000 rpm). If the regulator is jammed in the open position, the engine constantly receives excess air, which leads to overconsumption of fuel.

5. Check Engine won't catch fire. Unlike sensors, RX rarely causes errors in the ECUBecause it is not a sensor. The exception is a chain break, which can be fixed as P0505 ("Idle control system malfunction").

⚠️ Attention: If the turnovers float only with the air conditioner on or powerful electric consumers (Heat, lights, glass heating), the problem may lie in the generatorNot in RX. Before replacing the regulator, check the voltage of the onboard network!
  • 🔥 A common mistake of diagnosticians: write off floating revolutions to DMRC. Before the sensor is replaced be sure to check the RX - it's cheaper and easier.
  • ❄️ Winter nuance: If the speed is galloping only on a cold engine, it may not be the fault of RX, but ventilator (PCV).
  • 🛠️ Mechanical check: when switched off ignition, the RX should "click" when touching with a finger. If not, the winding break or jamming.

How to Check RXX for Lancer 9:3 Reliable Methods

Diagnostics of the idling regulator does not require complex equipment. Multimeter and basic skills of working with electricity are enough. Below are three methods of verification, from the simplest to the most accurate.

1. Visual inspection and mechanical inspection

Remove the RX from the throttle node (unscrew two screws) and examine it:

  • 🔍 The needle should be clean, without scorching and mechanical damage.
  • 🧲 The spring inside the body is intact, without deformations.
  • 🔌 The connector must not have traces of oxidation or burning of contacts.

Connect the connector back and turn on the ignition (without starting the engine). A correct RX should "click" - this is the sound of the stepper motor. If there is no click, a chain break or malfunction ECU.

2. Multimeter check

Transfer the multimeter to resistance measurement mode (200 ohms) and check the pairs of RXX contacts:

Contacts Normal resistance (OM) What does deviation mean?
A-B, C-D 40–80 Break or short circuit in the windings
A-C, B-D Infinity (∞) Inter-turn closure
Any contact on the "mass" Infinity (∞) Break-through on the hull

If at least one parameter does not meet the norm, the RX should be replaced.

3. Diagnostics with scanner (ELM327)

Connect the adapter. ELM327 To the diagnostic connector and check the parameters:

  • 📉 Rotate XX: should be stable in the range of 700-900 rpm (for 4G18/4G94).
  • 🔧 Position RX: in the programme (e.g. Torque Pro) the parameter shall be displayed IAC Position (usually 20 to 50 units). If the value jumps or is equal to 0, the regulator is faulty.

Remove the battery terminal for 10 minutes (reset ECU adaptations)

Clean the throttle node of the scorching

Check the integrity of the RX sealing ring

Connect the connector to install the regulator (click check)

Start the engine and let it work for 5 minutes to adapt.

Step by step instructions for replacing the RXX with the Mitsubishi Lancer 9

Replacement of the idling regulator by Lancer 9 It takes no more than 30 minutes and does not require special tools. The main thing is to observe the sequence and not damage the throttle node. Below is a detailed instruction with nuances for engines 4G18 and 4G94.

Required tools and materials

  • ⚒️ Cross screwdriver (PH2).
  • 🧴 Carburettor or throttle cleaner (LIQUI MOLY Pro-Line Drosselklappen-Reiniger).
  • 🔌 Multimeter (to check new RX before installation)
  • 🛠️ New sealing ring (goes with RX or bought separately, art). MD360423).

Step-by-step replacement process

  1. Turn off the battery. Remove the negative terminal for 10-15 minutes to reset the adaptations ECU. This is a must-do step, otherwise the new RX may not work properly.

  2. Remove the throttle knot. Nana 4G18 It is enough to loosen the air duct clamps and disconnect the connector TPS. Nana 4G94 It may be necessary to remove the intake manifold (4 bolts by 10).

  3. Dismantle the old RXX. Unscrew the two screws of the mount (don't lose the spring washers!) and carefully remove the regulator. Clear the seat of the stain.

  4. Install a new RX. Before installation, check the resistance of the windings with a multimeter (see para. "Verification" section. The sealing ring should sit tightly, without distortion.

  5. Connect the connector and check the work. Turn on the ignition (without starting the engine) - a click should sound. Start the engine and let it work for 5-10 minutes to adjust.

⚠️ Attention: Nana Lancer 9 s ECU Mitsubishi MUT-III after replacement of RX throttle-training. For this:

1. Turn off the engine, turn off the ignition for 10 seconds.

2. Turn on the ignition (without starting the engine), wait 3 seconds.

3. 5 times fully press and release the gas pedal for 5 seconds.

4. Wait 7 seconds, then press the gas pedal to the end and hold for 20 seconds until it blinks. Check Engine.

5. Release the pedal, start the engine and check the revs.

💡

If the RXX is unstable after replacement, check leakiness. Often, air suction through cracked hoses or a manifold gasket simulates a malfunction of the regulator.

Which RX to choose for Lancer 9: original vs analogues

There are many options on the market for RCX Mitsubishi Lancer IXFrom original to budgetary counterparts. The main rule is: Don’t buy regulators of unknown brands They often fail in 1-2 months. Below are the proven options with articles and average prices (for 2026).

Type Articulum Brand Price (rupe) Notes
Original MD360423 Mitsubishi 4500–6000 Best quality, resource of 100+ thousand. km
Analogue (premium) 25800-77010 Hitachi 3200–4000 Japanese production, a complete analogue of the original
Analogue (budget) IAC003 ERA 1200–1800 Suitable for temporary replacement, resource ~30 thousand. km
Analogue (China) 25800-77010 (clone) No brand. 800–1200 30-40% risk of marriage, often throwing a needle

When choosing, pay attention to:

  • 🔍 Marking on the shell: original Mitsubishi And the catalog number, which is laser-engraved.
  • 📦 Package: In the box there should be a sealing ring and instructions (for analogues).
  • 🛒 Place of purchase: Avoid markets and unverified online stores. The best option is for official dealers or Exist.ru, Autodoc.
How to distinguish a fake RXX from the original?

1. Weight: The original weighs ~150 g, a fake - 100-120 g (less massive body).

2. Needle: The original cone is perfectly polished, the fake - burrs and roughness.

3. Packaging: The original is packed in a dense cardboard with a hologram, a fake - in a bubble film.

4. Price: if RX is cheaper than 2500 rubles, it is 100% fake or used.

Typical Errors in Replacing RXX and How to Avoid Them

Even experienced car owners make mistakes when working with the idle regulator. Here are the most common ones and ways to prevent them:

  1. Non-cleanliness. Dust or fine debris trapped in the throttle assembly when replaced can jam the needle of the new RX. Decision: Before installation, blow the seat with compressed air and wipe with a lilaless napkin.

  2. Ignoring the ECU adaptation. After replacement ECU The new regulator should be “trained.” If you don’t, the swelling will float. Decision: complete the training procedure (see para. section “Replacement of RXX”).

  3. Damage to the O-ring. A skewed or torn ring leads to air sucking and unstable turnovers. Decision: Always use a new ring and lubricate it with a thin layer of engine oil before installation.

  4. Buying incompatible RX. Regulators for 4G18 and 4G94 They look similar but have different calibrations. Decision: Check the article with the VIN number of the car through Mitsubishi Parts Catalog.

  5. Eye diagnostics. Many people change RXC without checking, focusing only on symptoms. Decision: Always test the regulator with a multimeter or scanner before replacing.

1. Throttle position sensor (TPS) - its malfunction gives the same symptoms.

2. The tightness of the inlet tract (hoses, gaskets).

3. The state of spark plugs and high-voltage wires - ignition skips also cause floating turns.

Prevention and increase of RX resource

Average idling regulator resource per Lancer 9 - 80 to 120 thousand. km, but with proper care, this period can be increased by 1.5-2 times. Here are the key prevention measures:

  • 🧹 Cleaning the throttle. Every 30,000. Take off the throttle and clean it. carburettor (Do not use metal brushes!) Pay special attention to the RX channel - it can be blown with compressed air.
  • ⛽ Fuel quality. Bad gasoline with a high sulfur content accelerates the formation of sodium on the needle of RXX. Refuel at checked gas stations (for example, Gazpromneft, LUKOIL).
  • 🔋 Timely replacement of the air filter. A clogged filter increases the load on the RX, as the engine requires more air for stable operation.
  • 🚗 Proper operation. Avoid long-term engine operation at idle speeds (more than 10 minutes) - this leads to overheating of the RXX.

If you Lancer 9 Often stands in traffic jams or is operated in high humidity conditions, it is recommended:

  • 🌧️ Once a year, process RX contacts contact-lubrication (e.g., CRC 2-26) to protect against oxidation.
  • 🔥 Use it. fuel-cleaning (e.g., Wynns Injector Cleaner) every 10,000 km.
💡

If you often drive off-road, install an air intake dust-separator (e.g., Mann C 29 003). This will reduce the ingress of abrasive particles into the throttle node and prolong the life of RXX.

FAQ: Frequent questions about RX on Mitsubishi Lancer 9

Can I drive with a faulty RX?

Technically possible, but it can be:

  • Increased fuel consumption (up to +2 l / 100 km).
  • Snap when driving at low speeds (for example, in traffic jams).
  • Risk of stalling at traffic lights or when braking.

If the RX wedges in the open position, the engine will constantly work at increased speeds (1200-1500 rpm), which will accelerate the wear of the engine.

How to reset the ECU adaptation after replacing the RXX?

There are two ways:

  1. Hardware discharge: remove the battery terminal for 10-15 minutes.
  2. Programme reset: perform the procedure for training the throttle (see para. section “Replacement of RXX”).

After discharge ECU The first 5-10 km engine can work unstable - this is normal (retraining is underway).

Why is the new RXX not working properly?

Reasons:

  • The training procedure has not been completed ECU.
  • Sucking air through a damaged sealing ring.
  • Regulator marriage (especially in cheap analogues).
  • Contaminated throttle node (nagar interferes with the normal operation of the needle).

Decision: repeat the training, check the tightness of the intake tract and clean the throttle.

Can I repair the RCX or just replace it?

Repairs are only possible in two cases:

  • Oxidating contacts – clean them contact-lubrication.
  • Switching the needle due to the scorching - wash the regulator in carburettor (nothing to disassemble)

If the winding of the stepping engine is burned or the needle thread is worn out - only a replacement. The cost of repair in the service (rewinding windings) is comparable to the price of a new RX.

What other sensors can affect idling?

In addition to RXX, the stability of turnovers XX affect:

  • Throttle position sensor (TPS). When a malfunction is made, it makes an error. P0120.
  • Air mass flow sensor (DMRV). Signaling an error P0100.
  • Coolant temperature sensor (ECT). In false testimony. ECU Incorrectly adjusts the composition of the mixture.
  • Crackcase ventilation valve (PCV). A clogged valve leads to oil vapor sucking and unstable turnovers.

Before replacing the RXX, check these sensors with a scanner or multimeter.