Infiniti Qx4 Code 1491 Can You Continue to Drive

Is the Check Engine Light on or Service Engine Soon illuminating on your Infiniti dashboard? Learn the common problems causing the warning light to come on and know possible solutions to fix the problem by following the procedures below.

Infiniti check engine light will come on and remain on when the On-Board Diagnostic (OBD) system detects a problem related to the engine or emission system. In this guide, you will learn about common problems that trigger Infiniti to come on and how to read the fault codes yourself with a YOUCANIC scanner.

What does Check Engine Light or Service Engine Soon mean on an Infiniti?

Infiniti Check Engine Light Service Engine Soon Infintiy G35 G37 JX35 Q50 QX60 Qx 56

Suppose the check engine light comes on in your Infiniti. In that case, the onboard diagnostics system (or OBD II) has detected a malfunction in the vehicle's emissions, ignition, fuel, or exhaust systems. In some cases, the Infiniti check engine light may also be triggered by transmission issues.

All 1996 and newer Infiniti vehicles have a Check engine light or a Service Engine Soon light. Including models such as QX80, QX60, QX30, G37, G35, FX35, Q50 JX35. Infiniti check engine light may also be referred to as CEL or MIL.

While your Infiniti check engine light stays on, the vehicle may have increased emissions, decreased fuel economy, and performance issues. Depending on the problem, your Infiniti may also enter "Home Limp Mode." In this mode, your vehicle speed will be limited to 40 MPH. Engine RPM and power will be limited as well.

Symptoms

Infinti engine shaking service engine light soon on

What you may notice when the Infiniti service engine soon light comes on is that the engine shakes, but other symptoms include:

Rough running
Engine Misfire or juddering
Lack of power
Poor throttle response
Unusual sounds
Smoke from the exhaust

These symptoms indicate that your engine is not running as it should. If you don't notice any symptoms, the problem most likely is related to the emissions system. Still, you shouldn't ignore this warning lightly. Have your Infiniti diagnosed soon.

How to Reset Infiniti Check Engine Soon Light

Hundreds of fault codes can trigger the Infiniti check engine soon light. You, your mechanic, or your Infiniti dealer will need to read the Engine Control Unit (ECU).

In this section, you will learn how to read Infiniti fault codes yourself using a YOUCANIC scanner. Codes should only be reset after fixing the problem(s).

Locate the diagnostic port under the dashboard.
Connect the YOUCANIC UCAN-I scanner to the diagnostic port.
Turn on the ignition and turn on your scanner. The YOUCANIC scanner will power on as soon as you turn on the ignition.
Select Read Codes from the main menu. Check all Pending, Current, and Permanent codes.

Write down the code(s) and do further research to understand what each code means.

Fix the problems you discover, return to the main menu, select Clear Fault Codes, and press OK. This will reset your Infiniti check engine codes.

If a loose gas cap triggered your Infiniti check engine light, you could go to Clear Codes, which will erase the check engine light. Otherwise, do not clear the codes without fixing the underlying problem.

What Causes Check Engine Light on an Infiniti?

The most common problems that cause the check engine light on an Infiniti vehicle are worn spark plugs, bad oxygen sensors, or a loose gas cap.

Here are Infiniti check engine soon-related problems that happen 'more-than-usual:

Variable Valve Timing

Almost all Infiniti engines are equipped with Variable Valve Timing. This electro-hydraulic system is operated by the engine oil, meaning that poor oil quality or low oil level can cause the engine to run incorrectly.

This will affect the Intake valve timing control. You may experience hard starting, poor idle and/or stalling, loss of power, and hesitation on accelerations. Another possible cause is a leaking galley gasket located within the engine, behind the timing chain.

Codes: P0021 or P0011.

Timing control issue

Another possible timing control issue is exhaust side related. Control is done by an electromagnetic solenoid that can fail with time. Although this can cause driveability issues such as rough running, the only symptom you will see is a check engine light in most cases.

Codes: P0014 or P0024.

Mass Air Flow Sensor

You may have a situation when your engine runs roughly, stalls, does not want to idle, and notices a black exhaust smoke. A dirty MAF sensor can cause this. Only use MAF cleaner fluid for cleaning the sensor.

Code P0101

Oxygen Sensor

Downstream o2 sensors can fail, giving false catalytic converter efficiency readings. This can be caused by a bad sensor or heat-damaged wiring, as it goes near the exhaust pipes.

Codes: P0138 and P0158

Vacuum Leak

Infinitis are powered by V6 or V8 engines. The intake manifolds are quite complex, with various possible intake vacuum leak points. As that will cause lean running conditions, you might experience rough idle, lack of power, or hesitation on accelerations.

Codes: P0171 or P0174

Misfire

A random cylinder misfire is something you might experience in your Infiniti. As this usually happens sporadically, tracing down the cause can be tricky. Besides the obvious bad spark plugs or ignition coil, it can also be caused by dirty fuel injectors or intake air leaks.

Codes: P0300 P0301 P0302 P0303 P0304

EVAP Leak

As with most other cars, Infiniti too can suffer from various EVAP related problems. Usually, you will have a large EVAP leak. Although this can be caused by a gas cap that doesn't seal, you may have a leaking Evap Canister vent valve.

Code: P0455

Throttle Body

The throttle body may be clogged with carbon build-up if your engine idles roughly. You will need to clean it with a carb cleaner. However, in most cases, this will cause a high idle speed and a check engine light. To remedy this, try the throttle body relearning procedure.

Codes: P0507

Automatic Transmission

Automatic transmission gearboxes have a well-known weak point. A transmission valve body can have an electrical fault, which sends the gearbox into a limp mode and triggers a ˜check engine light. The root of the problem is usually a broken solenoid electrical connector, which can be soldered instead of replacing the valve body unit.

Code: P1757 – Front Brake Solenoid Circuit or P0720.

Why is my Infiniti Check Engine Light Flashing On and Off?

When your Infiniti check engine light flashes or blinks constantly, it indicates a misfire on one or more cylinders. The problem could be something as simple as a bad spark plug or ignition coil. It could also indicate a more serious problem, such as a bad head gasket or catalytic converter.

There is no need to panic if your Infiniti check engine light is flashing. You should avoid driving your Infiniti if the check engine light is flashing. Driving an Infinity with a flashing check engine light would quickly damage a catalytic converter and cause the engine to overheat.

What to do when the Infiniti check engine light comes on?

Check the gas cap. Please remove it. Inspect it for damage. Reinsert the gas cap and tighten it properly. You may replace the fuel cap if you get a fault code for a minimal EVAP leak.
Allow the engine to cool down. Once the engine is cool, check the engine coolant and oil level. If you decide to drive,monitor the engine temperature gauge, and ensure the engine is not overheating. Also, if the engine is shaking or your Infiniti check engine light flashes, do not continue driving as this can cause severe damage to the engine and catalytic converter. If there are no performance issues, you may continue driving if the engine is NOT overheating and the oil light is NOT on.
Read fault codes from the Engine Control Unit (ECU).
Write down the code and do some more research on what the code means.

Reset Engine Control Unit (ECU)

Accelerator Pedal Release Position Learning

Make sure that the accelerator pedal is fully released.
Turn the ignition switch ON and wait for at least two seconds.
Turn the ignition switch OFF and wait at least ten seconds.
Turn the ignition switch ON and wait at least two seconds.
Turn the ignition switch OFF and wait at least ten seconds.

Throttle Valve Closed Position Learning

Make sure that the accelerator pedal is fully released.
Turn the ignition switch to ON.
Turn the ignition switch to OFF; wait at least ten seconds.
Ensure the throttle valve moves during the above ten seconds by confirming the operating sound.

Common Infiniti Check Engine Light Codes

Show Codes

P0100 MAF Sensor
P0105 Absolute Pressure Sensor
P0110 IAT Sensor
P0115 ECT Sensor
P0120 TP Sensor
P0125 ECT Sensor
P0130 Closed Loop, Bank 1 Or Front O2S, Bank 1
P0131 Front O2 Sensor, Bank 1 Lean Shift Monitoring
P0132 Front O2 Sensor, Bank 1 Rich Shift Monitoring
P0133 Front O2 Sensor, Bank 1 Response Monitoring
P0134 Front O2 Sensor, Bank 1 High Voltage
P0135 Front HO2S Heater, Bank 1
P0136 Rear O2S, Bank 1
P0137 Rear O2S, Bank 1 Minimum Voltage Monitoring
P0138 Rear O2S, Bank 1 Maximum Voltage Monitoring
P0139 Rear O2S, Bank 1 Response Monitoring
P0140 Rear O2S, Bank 1 High Voltage
P0141 Rear H02S Heater, Bank 1
P0150 Closed Loop, Bank 2 Or Front O2S, Bank 2
P0151 Front O2 Sensor, Bank 2 Lean Shift Monitoring
P0152 Front O2 Sensor, Bank 2 Rich Shift Monitoring
P0153 Front O2 Sensor, Bank 2 Response Monitoring
P0154 Front O2 Sensor, Bank 2 High Voltage
P0155 Front HO2S Heater, Bank 2
P0156 Rear H02S Sensor, LH Bank
P0157 P0158 P0159 P0160 Oxygen Sensor
P0161 Rear H02S Heater, LH Bank Or Bank 2
P0171 Fuel System Lean, Bank 1
P0172 Fuel System Rich, Bank 1
P0174 Fuel System Lean, Bank 2
P0175 Fuel System Rich, Bank 2
P0180 Tank Fuel Temp Sensor
P0300 Random Misfire
P0301 through P0308 Misfire, Cylinder No. 1 through 8
P0325 Knock Sensor, Bank 1
P0330 Knock Sensor, Bank 2
P0335 CKP Sensor (Pos)
P0340 CMP
P0400 EGR System
P0402 EGRC/BPT Valve
P0403 EGR Volume Control Valve Circuit
P0420 TW Catalyst System, Bank 1
P0430 TW Catalyst System, Bank 2
P0440 EVAP Small Leak
P0443 Purge Control/V & S/V
P0446 Vent Control Valve
P0450 EVAP Pressure Sensor
P0500 Vehicle Speed Sensor
P0505 IACV/AAC Valve
P0510 Closed TP Sensor
P0600 A/T Comm Line
P0605 ECM/ECU
P0705 PNP Or Inhibitor Switch
P0710 ATF Temp Sensor
P0720 VSS A/T
P0725 Engine Speed Signal
P0731 A/T 1ST Signal
P0732 A/T 2ND Signal
P0733 A/T 3RD Signal
P0734 A/T 4TH Signal Or TCC
P0740 TCC SV Solenoid
P0744 A/T TCC Signal
P0745 Line Pressure S/V
P0750 Shift Solenoid/V A
P0755 Shift Solenoid/V B
P1105 MAP/BARO Switch SOL/V
P1110 Intake Valve Timing Control, LH Bank
P1120 TP Sensor 2
P1125 Tandem TP Sensor
P1130 Swirl Control Valve Control Solenoid Valve
P1135 Intake Valve Timing Control, RH Bank 2
P1140 Intake Valve Timing Control Position Sensor, LH Bank 1
P1145 Intake Valve Timing Control Position Sensor, RH Bank 2
P1148 Closed Loop, Bank 1
P1165 Swirl Control Valve Control Vacuum Check Switch
P1168 Closed Loop, Bank 2
P1210 Traction Control Signal Circuit
P1220 FPCM
P1320 Ignition Signal, Primary
P1335 CKP Sensor (Ref)
P1336 CKP Sensor (POS) Cog
P1400 EGRC Solenoid/V
P1401 EGR Temp Sensor
P1402 EGR System
P1440 EVAP Small Leak
P1441 VC/V Bypass/V
P1443 Canister Control Vacuum Check Switch
P1444 Purge Volume Control/V
P1445 Purge Volume Control/V
P1446 Vent Control Valve
P1447 EVAP Purge Flow
P1448 Vent Control Valve
P1490 VC/V Bypass/V
P1491 VC Cut/V Bypass/V
P1492 Purge Control/V S/V
P1493 Purge Control/V & S/V
P1605 A/T Diag Comm Line
P1705 TP Sensor A/T
P1706 PNP Switch
P1760 Overrun Clutch S/V
P1900 Cooling Fan

We hope you find the Infiniti Check Engine Light On – Service Engine Soon Problem guide helpful. Check these troubleshooting and repair guides for more help on your Infinity.

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Source: https://www.youcanic.com/infiniti-check-engine-light-service-engine-soon-problem/