10 Common Problems that Trigger Honda / Acura Check Engine Light

Is there a Check Engine Light illuminating your Honda/Acura dashboard? By following the procedures below, learn the common problems why your Check Engine Light illuminates on your Honda or Acura. This article will discuss common problems that trigger the Acura and Honda check engine light.

Oxygen Sensor

Oxygen sensors (O2) may fail on Acuras. When this happens, there is no way to measure the amount of oxygen in your Acura’s exhaust system. The engine will end up burning more fuel than needed. Not only will you notice poor fuel mileage, but if this problem is ignored for a long period, it can cause damage to the catalytic converter.

Acura Oxygen Sensor Symptoms

• Poor fuel economy
• Acura may idle too high.
• High fuel consumption

Acura Oxygen CEL Codes

• P0135 ACURA O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1
• P0133 ACURA O2 Sensor Circuit Slow Response Bank 1 Sensor 1
• P0141 ACURA O2 Sensor 1 Sensor 2 Heater Circuit Malfunction Bank
• P0158 ACURA O2 Sensor Circuit High Voltage Bank 2 Sensor 2
• P0174 ACURA Fuel System Too Lean Bank 2

Catalytic Converter

The catalytic converter may fail on Acuras causing the check engine light to come on. Acura’s fuel efficiency will decrease if the catalytic converter fails or gets clogged. If you step on the gas pedal, you may feel that your Acura is struggling to accelerate. If your cats are completely clogged, your Acura will not even start.

You won’t be able to pass an emissions test with a failed catalytic converter. Replacing the catalytic converter at Acura dealerships will cost anywhere from $900 to $1600. A cheaper alternative is to install an aftermarket catalytic converter at a fraction of the dealer’s cost.

Symptoms

• Acura may not start
• Poor acceleration
• Acura struggles to go uphill.
• Failed emission test
• Significant fuel efficiency decrease

Acura Catalytic Converter Codes

• P0420 ACURA Catalyst System Efficiency Below Threshold Bank 1
• P0430 ACURA Catalyst System Efficiency Below Threshold Bank 2
• P2096 Post Catalyst Fuel Trim System Too Lean Bank 1

Mass Air Flow Sensor (MAF)

The mass airflow sensor on Acura measures the amount and temperature of the air entering the engine. This allows the engine to determine how much fuel to send to the engine to maintain the proper air-to-fuel ratio.

The Acura check engine light will come on when the MAF sensor fails. If ignored for a long period, a bad MAF will cause damage to the spark plugs, oxygen sensors, and, ultimately, the catalytic converter. Replacing the MAF sensor in an Acura is an easy DIY.

Symptoms

Symptoms of a bad MAF sensor on an Acura include:

• hard to start
• engine stalls
• Acura starts, then dies
• Acura hesitates under acceleration
• engine hiccups
• higher RPMs at idle

Mass Air Flow Sensor Codes

• P1103 ACURA Mass Airflow Sensor Higher Than Expected
• P0101 ACURA Mass Air Flow Circuit Range/Performance
• P0068 ACURA Manifold Absolute Pressure/Mass Air Flow Sensor
• P0102 Mass or Volume Air Flow Circuit Low Input
• P0103 Mass or Volume Air Flow Circuit High Input
• P0104 Mass or Volume Air Flow Circuit Intermittent

Spark Plugs

Sparks plugs are the most critical part of an Acura engine. They ignite the fuel in the combustion chamber. If the Acura has high mileage and the spark plugs have never been changed, you will notice performance issues, and even the check engine light may come on.

Symptoms

Symptoms of a worn Acura spark plug include:

• high fuel consumption
• poor throttle response
• engine idles roughly
• Acura hard to start
• engine hesitation
• high fuel consumption

Acura Spark Plug Related DTC Codes

• P0300 ACURA Random Cylinder Misfire Detected
• P0301 ACURA Cylinder Number 1 Misfire Detected
• P0302 ACURA Cylinder 2 Misfire Detected
• P0303 ACURA Cylinder 3 Misfire Detected
• P0304 ACURA Cylinder 4 Misfire Detected
• P0305 ACURA Cylinder 5 Misfire Detected
• P0306 ACURA Cylinder 6 Misfire Detected

Ignition Coils

Acura ignition coils may fail to cause the check engine light to come on. Acura ignition coils convert twelve volts of current to thousands of volts needed to create the spark at the tips of the spark plug. They are installed on top of the spark plug. Ignition coils generate up to 50,000 volts and release this voltage at the spark plug’s tip, which causes the spark and ultimately fires up the compressed air/fuel mixture.

If you read the codes from your Acura and get a code related to a faulty ignition coil, replace it as soon as possible. You don’t need to replace all the ignition coils; just replace the faulty one, at least. If you drive your Acura with the check engine light on and a bad ignition coil, you will eventually cause the catalytic converter to fail, which is a much more expensive repair. Replacing the ignition coils on an Acura is an easy task. If you have ever changed the oil, you can change an ignition coil on a four-cylinder Acura.

Symptoms

If one ignition coils fail on your Acura, it will trigger the check engine light. Here are some of the common symptoms you will notice if you have a bad ignition coil on an Acura:

• Engine shaking
• Acura hesitates to start
• Poor fuel economy
• Engine misfiring
• Acura stalling
• Catalytic converter glowing red due to unburned fuel from the engine
• Acura backfires
• Acura idles rough

Acura Ignition Coil Fault Codes

• P0300 ACURA Random Cylinder Misfire Detected
• P0351 ACURA Ignition Coil 1 Circuit Malfunction
• P0352 ACURA Ignition Coil 2 Circuit Malfunction
• P0353 ACURA Ignition Coil 3 Circuit Malfunction
• P0354 ACURA Ignition Coil 4 Circuit Malfunction
• P0355 ACURA Ignition Coil 5 Circuit Malfunction
• P0356 ACURA Ignition Coil 6 Circuit Malfunction
• P1394 Ignition Coil Power Output Stage 2 Malfunction

Purge Valve

The evaporative emissions purge control valve (EVAP) can cause the check engine light on Acura. The purge valve controls the amount of fuel vapor purged from the charcoal canister. It allows vapors to enter the engine instead of being released into the atmosphere. On high mileage Acuras, the purge valve can stick, triggering the check engine light.

Symptoms

Some of the most common symptoms of a sticking purge solenoid include:

• Check engine light on
• Acura has a rough idle

Acura Purge Valve Related Codes

• P0443 ACURA EVAP Canister Purge Valve Circuit Malfunction
• P1457 ACURA Evaporative Emissions Control System Leakage
• P0496 ACURA Evaporative Emission System High Purge Flow
• P0455 ACURA EVAP System Large Leak Detected

Stuck Thermostat

If the thermostat fails on your Acura, it can take too long for the engine to warm up. The engine control unit (ECU) in your Acura detects this. It will trigger a fault code such as P0128 and turn on the check engine light because the engine is taking too long or isn’t able to reach the normal operating temperature.

When the thermostat on an Acura gets stuck in the open position, it takes a very long time for the engine to warm up. If the thermostat gets stuck in the closed position, your Acura engine will overheat because no coolant is circulating and cooling down the engine.

Symptoms

A few of the symptoms that you may notice when the thermostat is stuck:

• Acura checks the engine light on with code P0128
• The engine takes a long time to warm up
• Poor engine performance
• Engine overheating if thermostat stuck closed.

Thermostat Related Fault Codes

• P0128 ACURA Coolant System Malfunction
• P1486 ACURA Thermostat Range/Performance Problem
• P0118 ACURA Engine Coolant Temperature Sensor 1 Circuit High

Transmission Problem

Acura check engine light may turn on due to problems with the automatic transmission. When you read the fault codes with an OBD-II scanner, you will get fault codes that start with P07XX. These are generic transmission codes. To properly diagnose Acura transmission problems, you must use a multi-system scanner capable of reading Acura transmission codes.

Symptoms

You may notice some symptoms when transmission problems cause Acura check engine light.

• Acura won’t shift gears.
• Acura stuck in gear and check engine light on
• Check Engine Light and D4 light flashings.
• No response when you press the gas pedal

Acura CEL / Transmission Fault Codes

• P0740 ACURA Transmission Lock-Up Control System Fault
• P0700 ACURA Automatic Transmission Fault
• P0710 ACURA Transmission Fluid Temperature Sensor Circuit Fault
• P0847 ACURA 3rd Clutch Transmission Fluid Pressure Switch

VTEC System

Variable Valve Timing & Lift Electronic Control (VTEC) system activates the rocker arm oil control solenoid, and it charges/discharges the hydraulic circuit of the VTEC mechanism. This allows the valve timing to change.

The engine control module monitors oil pressure in the hydraulic circuit of the VTEC mechanism and the rocker arm oil pressure switch downstream of the rocker’s arm oil control solenoid. If there is a difference between the oil pressure in the hydraulic circuit and the oil pressure, that is determined by the status of the rocker arm oil pressure switch, and a fault code is stored.

Symptoms

• Poor engine performance
• Poor acceleration
• Acura Check Engine Light on

VTEC Related Fault Codes

• P1259 ACURA VTEC System Malfunction
• P1258 ACURA VTEC System Malfunction
• P1253 ACURA VTEC System Malfunction
• P1279 ACURA VTEC System Malfunction Front Bank 2
• P2646 ACURA Rocker Arm Oil Pressure Switch Circuit Low Voltage
• P2649 ACURA Rocker Arm Oil Control Solenoid Circuit High Voltage

Vacuum Leaks

Acura check engine light may come on due to vacuum leaks. A vacuum leak can be a problem if your engine isn’t idling properly or the RPMs fluctuate between high and low. Hoses on Acura engines can dry out and crack over time. As this happens, they create small vacuum leaks allowing measured air to enter the motor. Loose hose clamps and connections can also cause vacuum leaks. Replacement vacuum hoses are cheap, but the real challenge is tracking down to find what’s causing the vacuum.

Gas Cap Loose

A loose Acura gas cap can cause the check engine light. We all have forgotten or will forget to put on the gas cap or tighten it until you hear it click. The gas cap seals the fuel tank. The fuel tank needs to maintain a constant pressure lower than the atmospheric pressure. That’s why the check engine light may turn on if you forget to tighten the gas cap.

It is possible that the gas cap gasket also fails, and it no longer provides a proper seal. If you left the gas cap off or lose, the check engine light will turn on. Just tighten the gas cap. As the Acura goes through driving cycles, it will reset the check engine light on its own within a couple of days.

Loose Gas Cap Codes

• P0455 Acura EVAP System Large Leak Detected
• P1456 AcuraEvaporative Emissions Control System Leakage
• P1457 Acura Evaporative Emissions Control System Leakage
• P0442 Acura EVAP System Very Small Leak Detected

Conclusion

Hundreds of possible fault codes can trigger the check engine light to stay on in your Honda or Acura vehicle. The three most common issues are worn spark plugs, bad oxygen sensors, or catalytic converters working below efficiency. Instead of guessing what is wrong, use an OBD-II scanner to read the fault codes.

We hope you find the 10 Common Problems that Trigger Honda / Acura Check Engine Light guide helpful. Check these troubleshooting and repair guides for more help on your Honda.