Why Does My Infiniti G35 Shuts Off While Driving

If your Infiniti G35 shuts off while driving, it’s often due to electrical issues, fuel system problems, or a failing crankshaft position sensor. Ignoring these symptoms can lead to dangerous situations, so early diagnosis and repair are crucial for safety and reliability.

Key Takeaways

• Crankshaft Position Sensor Failure: A faulty crankshaft position sensor is one of the most common reasons the G35 stalls while driving. It disrupts engine timing and fuel delivery.
• Electrical System Issues: Loose wiring, corroded connectors, or a failing alternator can cause sudden power loss and engine shutdowns.
• Fuel Pump or Filter Problems: A weak fuel pump or clogged fuel filter restricts fuel flow, leading to stalling, especially under load or at low speeds.
• Idle Air Control Valve Malfunction: A dirty or failed IACV can cause erratic idling and stalling when coming to a stop or accelerating.
• Mass Air Flow Sensor (MAF) Issues: A dirty or defective MAF sensor sends incorrect air intake data, causing the engine to run too lean or rich and shut down.
• Ignition System Failures: Worn spark plugs, bad coils, or damaged ignition components can lead to misfires and sudden engine cutoffs.
• Check Engine Light and Diagnostic Codes: Always scan for OBD2 codes when your G35 stalls—this helps pinpoint the exact cause and avoid guesswork.

Why Does My Infiniti G35 Shuts Off While Driving?

Picture this: You’re cruising down the highway in your sleek Infiniti G35, enjoying the smooth purr of the V6 engine. Then, without warning, the engine sputters, the dashboard lights flicker, and your car shuts off completely. Your heart races as you coast to the shoulder, hoping it’s just a fluke. But if this has happened more than once, you’re not alone—and it’s not something to ignore.

The Infiniti G35, especially models from 2003 to 2007, is a beloved sports sedan known for its performance and reliability. However, like any aging vehicle, it’s prone to certain mechanical and electrical issues that can cause sudden engine shutdowns while driving. These stalling incidents aren’t just annoying—they’re dangerous. Losing power steering, brakes, and acceleration at speed can put you and others at serious risk.

Understanding why your Infiniti G35 shuts off while driving is the first step toward fixing it. The causes range from simple maintenance oversights to more complex electrical failures. The good news? Most of these problems are diagnosable and fixable with the right knowledge and tools. In this guide, we’ll walk you through the most common reasons your G35 might stall, how to identify them, and what you can do to prevent it from happening again.

Common Causes of Engine Stalling in the Infiniti G35

When your Infiniti G35 shuts off while driving, it’s usually a symptom of an underlying issue that’s disrupting the engine’s ability to run smoothly. The engine needs three key things to operate: fuel, air, and spark. If any of these are compromised—or if the engine’s sensors and control systems fail—your car can stall unexpectedly.

Let’s break down the most frequent culprits behind this frustrating problem.

1. Crankshaft Position Sensor Failure

One of the top reasons your Infiniti G35 shuts off while driving is a failing crankshaft position sensor (CKP sensor). This small but critical component monitors the position and rotational speed of the crankshaft, sending real-time data to the engine control unit (ECU). The ECU uses this information to control fuel injection and ignition timing.

When the CKP sensor goes bad, it can send incorrect or no signals at all. This confuses the ECU, which may cut fuel or spark, causing the engine to stall—often without warning. You might notice the car stalling at idle, when accelerating, or even while cruising.

Symptoms of a bad crankshaft position sensor include:
– Sudden engine shutdown
– Difficulty starting the car
– Intermittent stalling
– Check Engine Light (CEL) with codes like P0335 or P0336

The CKP sensor on the G35 is located near the harmonic balancer on the front of the engine. Over time, heat and vibration can damage the sensor or its wiring. Replacing it is relatively straightforward and costs between $50 and $150 for the part, plus labor if you don’t do it yourself.

2. Fuel System Problems

Your G35’s engine needs a steady supply of fuel to run. If that flow is interrupted, the engine will shut off. Two common fuel system issues are a failing fuel pump and a clogged fuel filter.

The fuel pump, located inside the gas tank, sends pressurized fuel to the engine. As it wears out, it may struggle to maintain proper pressure, especially under load or at higher speeds. You might notice your G35 stalling when going uphill, accelerating quickly, or after driving for a while (when the pump gets hot).

A clogged fuel filter is another issue. While the G35 doesn’t have a traditional inline fuel filter, it does have a filter screen inside the fuel pump assembly and a fuel pressure regulator. Over time, debris and sediment can clog these components, restricting fuel flow.

Signs of fuel system trouble include:
– Engine sputtering or hesitation
– Loss of power during acceleration
– Stalling when the tank is low on gas
– Hard starting

Replacing the fuel pump is more involved and may cost $300–$600, depending on labor. Regular maintenance—like using quality fuel and keeping the tank above a quarter full—can help extend the pump’s life.

3. Electrical and Wiring Issues

Modern cars like the Infiniti G35 rely heavily on electrical systems. A loose connection, corroded wire, or failing component can cause sudden power loss and engine shutdown.

Common electrical problems include:
– Loose or corroded battery terminals
– Faulty alternator
– Damaged wiring harnesses
– Bad ground connections

The alternator charges the battery and powers the car’s electrical systems while the engine runs. If it fails, the battery will drain, and the engine may shut off once the charge drops too low. You might notice dimming headlights, flickering dashboard lights, or a battery warning light before the stall.

Corrosion on battery terminals or ground points can also disrupt the electrical flow. The G35 has several ground points, including one near the transmission and another on the engine block. If these become corroded or loose, it can cause intermittent stalling.

Always check your battery and alternator first if your G35 shuts off while driving. A simple multimeter test can tell you if the alternator is charging properly (should be 13.5–14.5 volts with the engine running).

4. Idle Air Control Valve (IACV) Malfunction

The idle air control valve (IACV) manages the engine’s idle speed by regulating how much air bypasses the throttle plate when the throttle is closed. If the IACV is dirty, stuck, or failing, it can cause erratic idling, stalling at stoplights, or even shutdowns when decelerating.

On the G35, the IACV is part of the throttle body assembly. Over time, carbon buildup from oil vapors and fuel residue can clog the valve, preventing it from opening or closing properly.

Symptoms of a bad IACV include:
– Rough or fluctuating idle
– Stalling when coming to a stop
– High idle (above 1,500 RPM)
– Engine dying when the A/C is turned on

Cleaning the throttle body and IACV with carburetor cleaner can often resolve the issue. If cleaning doesn’t help, the valve may need replacement. This is a relatively inexpensive fix, typically under $100 for the part.

5. Mass Air Flow (MAF) Sensor Problems

The mass air flow (MAF) sensor measures how much air is entering the engine. This data helps the ECU calculate the correct amount of fuel to inject. If the MAF sensor is dirty or faulty, it can send incorrect readings, causing the engine to run too lean (not enough fuel) or too rich (too much fuel).

A malfunctioning MAF sensor can lead to:
– Hesitation or stumbling during acceleration
– Poor fuel economy
– Rough idle
– Sudden stalling, especially at low speeds

The MAF sensor on the G35 is located in the air intake duct, between the air filter box and the throttle body. It’s a delicate component that can be easily contaminated by oil, dirt, or debris.

Cleaning the MAF sensor with a dedicated MAF cleaner (never use regular spray cleaners) can often restore proper function. If cleaning doesn’t work, replacement is recommended. A new MAF sensor costs around $100–$200.

Diagnosing the Problem: What to Do When Your G35 Shuts Off

If your Infiniti G35 shuts off while driving, the first thing you should do is stay calm and safely pull over. Once you’re in a safe location, here’s a step-by-step approach to diagnosing the issue.

Step 1: Check for Warning Lights

When the engine stalls, check the dashboard for any warning lights. The most important one is the Check Engine Light (CEL). If it’s on, it means the ECU has detected a problem and stored a diagnostic trouble code (DTC).

Even if the light isn’t on during the stall, it may have flashed briefly. Some codes only appear under certain conditions, so it’s worth scanning for them.

Step 2: Use an OBD2 Scanner

An OBD2 scanner is a must-have tool for any G35 owner. Plug it into the OBD2 port (usually under the dashboard, near the steering column) and read the codes. Common codes related to stalling include:
– P0335/P0336: Crankshaft Position Sensor
– P0171/P0174: System Too Lean (often MAF or vacuum leak)
– P0300–P0306: Random/Multiple Cylinder Misfire
– P0505: Idle Air Control System Malfunction

These codes can point you directly to the source of the problem. For example, a P0335 code strongly suggests a crankshaft position sensor issue.

Step 3: Inspect Basic Components

Before diving into complex repairs, check the basics:
– Battery terminals: Are they tight and free of corrosion?
– Alternator output: Is it charging properly?
– Fuel level: Is the tank low? (A failing fuel pump may struggle with low fuel)
– Air filter: Is it dirty or clogged?

These simple checks can save you time and money.

Step 4: Test Drive and Monitor

After addressing any obvious issues, take the car for a test drive. Pay attention to:
– When the stalling occurs (idle, acceleration, cruising)
– Any unusual noises or vibrations
– Dashboard warning lights

Keep a log of when and how the stalling happens. This information can help a mechanic diagnose the problem faster.

Preventive Maintenance to Avoid Stalling

The best way to prevent your Infiniti G35 from shutting off while driving is through regular maintenance. Many stalling issues can be avoided with simple, proactive care.

Follow the Maintenance Schedule

Infiniti provides a recommended maintenance schedule for the G35. Stick to it. Key items include:
– Oil and filter changes every 5,000–7,500 miles
– Spark plug replacement every 60,000–100,000 miles (depending on type)
– Air filter replacement every 15,000–30,000 miles
– Fuel system cleaning every 30,000 miles

Using high-quality parts and fluids can also extend the life of critical components.

Use Quality Fuel and Additives

Cheap or contaminated fuel can clog injectors and damage the fuel pump. Use top-tier gasoline with detergents to keep the fuel system clean. Occasionally, add a fuel system cleaner (like Techron or Sea Foam) to remove deposits.

Keep the Battery and Electrical System in Good Shape

Clean battery terminals regularly and check for loose or corroded connections. Have the alternator and battery tested annually, especially if your G35 is over 10 years old.

Address Warning Signs Early

Don’t ignore rough idling, hesitation, or occasional stalling. These are early warning signs of a bigger problem. The sooner you address them, the less likely you are to experience a dangerous shutdown on the road.

When to See a Mechanic

While many G35 stalling issues can be diagnosed and fixed at home, some problems require professional help. See a qualified mechanic if:
– The Check Engine Light is on and you’re unsure of the cause
– You suspect a fuel pump or electrical issue
– The car stalls repeatedly despite basic repairs
– You’re not comfortable working on the engine or electrical system

A mechanic with experience in Nissan/Infiniti vehicles will have the tools and knowledge to perform advanced diagnostics, such as fuel pressure testing, oscilloscope analysis of sensor signals, and wiring inspections.

Conclusion

If your Infiniti G35 shuts off while driving, it’s a serious issue that demands immediate attention. While it can be alarming, the good news is that most causes are identifiable and fixable. From a failing crankshaft position sensor to a clogged fuel filter, the root of the problem often lies in one of a handful of common components.

The key is to act quickly. Use an OBD2 scanner to read diagnostic codes, inspect basic systems, and don’t ignore warning signs like rough idling or hesitation. Regular maintenance—like changing spark plugs, cleaning the MAF sensor, and using quality fuel—can go a long way in preventing stalling.

Remember, your safety is the top priority. If you’re ever unsure about a repair or feel uncomfortable working on your car, don’t hesitate to consult a professional. With the right care, your Infiniti G35 can continue to deliver the performance and reliability you love for many more miles.

Frequently Asked Questions

Why does my Infiniti G35 shut off when I come to a stop?

This is often due to a dirty or failing idle air control valve (IACV) or a vacuum leak. The IACV regulates idle speed, and if it’s clogged, the engine may stall when decelerating. Cleaning the throttle body and IACV can usually fix the issue.

Can a bad alternator cause my G35 to shut off while driving?

Yes. A failing alternator can’t charge the battery properly, leading to a loss of electrical power. This can cause the engine to shut off, especially if the battery drains completely. Look for dimming lights or a battery warning light as early signs.

How much does it cost to fix a stalling G35?

Costs vary depending on the cause. Replacing a crankshaft position sensor costs $100–$200, while a fuel pump replacement can run $300–$600. Electrical repairs may be less expensive if it’s a simple fix like cleaning terminals.

Is it safe to drive my G35 if it stalls occasionally?

No. Stalling while driving is dangerous and can lead to accidents. Even occasional stalling indicates an underlying issue that could worsen. Have the car inspected as soon as possible.

Can a dirty air filter cause my G35 to shut off?

A severely clogged air filter can restrict airflow, causing poor engine performance and stalling. However, it’s more likely to cause hesitation or rough running than a complete shutdown. Still, replacing a dirty filter is an easy and inexpensive fix.

How do I reset the ECU on my Infiniti G35?

To reset the ECU, disconnect the negative battery terminal for 10–15 minutes. This clears stored codes and resets adaptive learning. Reconnect the battery and drive the car to allow the ECU to relearn idle and fuel trim settings.