In this article, we take a look at common problems that trigger Acura check engine light.
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 burning more fuel than needed. Not only will you notice poor fuel mileage but if this problem is ignored for a long period of time it can cause damage to the catalytic converter.
Acura Oxygen Sensor Symptoms
Acura Oxygen CEL Codes
A loose Acura gas cap can cause the check engine light to come on. 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 which is lower than the atmospheric pressure. That's why if you forget to tighten the gas cap the check engine light may turn on.
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 loose 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
The catalytic converter may fail on Acuras causing the check engine light to come on. If the catalytic converter fails or gets clogged your Acura's fuel efficiency will decrease. 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 you anywhere from $900-$1600. A cheaper alternative is to install an aftermarket catalytic converter at a fraction of the dealer cost.
Acura Catalytic Converter Codes
The mass air flow sensor on Acura measures the amount and temperature of air entering the engine. This allows the engine to determine how much fuel to send to the engine so that the proper air to fuel ratio is maintained.
When the MAF sensor fails Acura check engine light will come on. If ignored for a long period of time 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 of a bad MAF sensor on an Acura include:
Mass Air Flow Sensor Codes
Sparks plugs are the most critical part of an Acura engine. They ignite the fuel in the combustion chamber.
If your 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 of worn Acura spark plug include:
Acura Spark Plug Related DTC Codes
Acura ignition coils may fail to cause the check engine light to come on. Acura ignition coils convert 12 volts 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 plugs tip which causes the spark and ultimately fire 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 one that is faulty at least. If you drive your Acura with 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 four-cylinder Acura.
If one of the ignition coils fails 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
The evaporative emissions purge control valve (EVAP) can cause the check engine light on Acura. The purge valve controls the amount of fuel vapor that is purged from the charcoal canister.
It allows for 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.
Some of the most common symptoms of a sticking purge solenoid include:
Acura Purge Valve Related Codes
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 and 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 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 closed position, your Acura engine will overheat because there is no coolant circulating and cooling down the engine.
A few of the symptoms that you may notice when the thermostat is stuck. Acura check engine light on with code P0128, Engine take a long time to warm up, Poor engine performance, Engine overheating if thermostat stuck closed
Thermostat Related Fault Codes
Acura check engine light may turn on due to problems with the automatic transmission. When you read the fault codes with an OBD2 scanner, you will get fault codes that start with P07XX. These are generic transmission codes.
To properly diagnose Acura transmission problems you will need to use a multi-system scanner that is capable of reading Acura transmission codes.
Acura CEL / Transmission Fault Codes
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 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.
VTEC Related Fault Codes
Acura check engine light may come on due to vacuum leaks. If your engine isn't idling properly or the RPMs fluctuate between high and low, a vacuum leak can be the problem. 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. Vacuum leaks can also be caused by loose hose clamps and connections. Replacement vacuum hoses are cheap but the real challenge is tracking down to find what's causing the vacuum.