In this guide, you will learn about common problems that trigger Dodge check engine light to stay on and how to diagnose the problem yourself.
What Does Dodge Check Engine Light Mean?
If your Dodge Check Engine Light (CEL) is staying on when you start the car or comes on while driving it indicates that the On-Board Diagnostics (OBD) system has detected a problem.
A solid check engine light does not always mean emergency but it is important to have the codes read as soon as possible.
If your Dodge check engine light is flashing, it means the ECU has detected an engine misfire. Do not operate your vehicle for an extended period. Driving when the check engine is flashing can cause damage to the engine and cataltyic converter.
Ignoring the CEL warning light can cause more problems down the road.
Also keep in mind that if your Dodge CEL/MIL light is on, your fuel economy may be lower and exhaust emission usually increases.
Your Dodge check engine light can come on for various reasons. While it could be something as simple as a loose gas cap, there are over 1000 diagnostic trouble codes (DTC) that can trigger the check engine light.
Without reading the codes it is impossible to know what is wrong. Below you will find instructions on how to read codes yourself or where you can have them read for free.
Symptoms you may notice when your Dodge check engine light is on.
- Check engine warning on dashboard
- Reduced engine power
- Hesitation when accelerating
- Engine shaking due to misfire
- Erratic transmission shifting or no shifting at all
- Reduced fuel economy
In some cases, you may not notice any symptoms at all except check engine light or service engine soon light on the dashboard.
Seven of the most common problems that can cause the check engine light to come on are:
- A failed spark plug or ignition coil
- A mass airflow sensor needs to be replaced.
- Loose gas cap or gas cap needs to be replaced.
- Damaged catalytic converter.
- Intake vacuum leak
- Leak in the EVAP system due to a cracked hose
- Faulty oxygen sensor
It is difficult to know why your Dodge check engine light is on, without reading the fault codes.
How to Diagnose Dodge check engine light
Let's take a look at how you can use an OBD-II scanner to read codes related check engine codes.
- Locate the OBD-II port under the dashboard on the driver's side. Plugin your OBD-II scanner.
- Turn on the ignition. It is not necessary to start the engine. If your Dodge has a Start/Stop button, press it twice without pressing the brake pedal to turn on the accessories and the OBD-II port.
- Read Dodge fault codes. Instructions on this step will vary depending on the scanner that you are using. For your convenience, we have provided videos on how to use various OBD2 scanners to read codes and clear Dodge check engine light.
Clearing codes without fixing the problem that triggered the CEL does not fix the problem. Always address the problem first then clear the check engine light.
These instructions work on 1996 and newer Dodge vehicles such as Dodge Grand Caravan, Stratus, Viper, Challenger, Charger, Avenger, Caliber, Dart, Magnum, Neon, Durango, and Journey.
What to do when the check engine light comes on?
If your Dodge check engine light is on, in most cases you can continue to operate the vehicle if there are no performance issues and the check engine light is NOT flashing. See the closest mechanic or Dodge dealer if the check engine light is flashing.
Monitor Dashboard Warnings
Check your dashboard warning lights and gauges. Make sure there are no warning lights for low oil pressure or engine overheating.
Drive with caution and continue to monitor how the car is running. If the engine sounds different, the problem may be serious and should be diagnosed immediately.
Check Gas Cap
Check your gas cap to make sure it is on tight. If you find that the gas cap was loose or removed, tighten it until you hear it click.
If you have a capless design, inspect the flap for debris and make sure it closes properly.
After a few driving cycles, the light will turn off on its own because the ECU will keep on checking the EVAP system.
It will take a few driving cycles for the light to reset and in most cases, the light resets within two to three days.
Monitor Engine Temperature
Next, you need to monitor the engine temperature. If your check engine light came on because of an engine misfire, it is possible that the engine is going to overheat.
If the engine does overheat, it can lead to a blown head gasket which can be a costly repair. Especially if your check engine light is flashing or blinking.
If the engine is overheating or the oil light is ON, you should pull over and shut off the engine as soon as possible.
Reduce Speed and Load
If your check engine light is on, reduce your speed and do not put unnecessary load on the engine. If you are towing a trainer either reduce the speed drastically or remove the load.
How to read Dodge codes without a scanner
On a few Dodge vehicles such as Dodge Dakota and Grand Caravans, for example, you can retrieve the codes without a scanner.
- Cycle the key in the ignition three times. Turn key to ON then OFF three times.
- Leave the key in the ON position.
- Wait five seconds.
- A code will be displayed on the instrument cluster where your vehicle miles display. For example P0300.
Check Engine Light Flashes 10 Times
If you turn the key to ON position (or key in ACC position) but do not start the engine you may notice that the check engine light flashes 10x times. This happens if you recently disconnected the battery or used an OBD-II scanner to clear the codes.
It means that one or more of the emissions systems is not ready, also known as the I/M readiness test.
All the systems will be tested as you drive the vehicle, and the light usually stops blinking after a few driving cycles.
If your Dodge CEL flashes 10 times at startup continue to drive your Dodge and the light should stop blinking within a few days. Do NOT drive if the car, if the CEL continues to flash when the engine is running.
It is important to understand that if your Dodge check engine light is flashing 10 times, and you take the car for an emission test, it will fail because at least one of the following systems is not ready:
- Ignition / Misfire
- Fuel System
- Heated Catalyst
- Evap System
- Secondary Air System
- Oxygen Sensor
- Oxygen Sensor Heater
- EGR System
Even if your check engine light turns off, but one or more of these systems is NOT READY, your Dodge is not ready for emissions testing.
Once all the systems listed above are tested by the on-board diagnostic system and the car is ready for emission test, the check engine light will come on for a few seconds then turn off. It will not blink and should not stay on when the engine is running.
If you think the light is flashing, 9 or 11 times, count it again. It should blink 10 times.
When you call your Dodge dealer or any auto mechanic, you will be asked to bring the car in for a diagnostic.
The reason is that they need to plug in a scan tool to read the codes from the ECU. This is a procedure that you can perform if you have the right tools.
For this checkup, Dodge dealers charge between $80 and $130. If your Dodge is still under warranty, your Dodge dealer will perform diagnostic free of charge.
Also, note that a few Dodge dealerships may offer free check engine light diagnostics.
Just reading the codes is the starting point. Your dealer will make suggestions on the parts that need to be replaced based on the diagnostic results.
The main advantage of taking your car to the dealer is that the scanner used at the dealership provides more detailed information than the code that you retrieve using a generic OBD-II scanner.
The diagnostic fee charged at the dealership or the mechanic does not include the cost to fix the problem.
If you decide to have the car fixed at the same place that performed the diagnostics, ask the manager to waive the diagnostic fee. In most cases, they will if you ask in advance.
While there are hundreds of Diagnostic Trouble Codes (DTCs), here are some of the most common fault codes that many Dodge owners may experience.
This code indicates a very small leak in the EVAP system. A common problem with Dodge trucks such as Dodge Ram gasoline engine is a rotted hose for EVAP system.
The hoses from the fuel tank to the engine can crack over time. The problem could also be NVLD valve. Along with the P0456, you may also get P0440 or P0442. These are EVAP codes. If you have any of these codes, check the gas cap as well.
P0456 & P0457
If the P0457 and P0457 codes come up and your check engine light is on, the first you need to do is to check or even replace the gas cap.
If the code remains, there is a high chance that you have a defective leak detection pump. Your Dodge leak detection pump can be accessed from underneath the car. It can be replaced without removing the fuel tank.
P0306, P0303 or P0300
These codes mean that the Engine Control Unit has detected an engine misfire. These codes can be caused by any of the following:
Bad spark plugs
Defective ignition coil
Fuel injector dirty
Mass airflow sensor
Damaged catalytic converter
These are just a few of the problems that can cause a cylinder misfire.
To determine the cause of P03XXX codes, you need to perform further troubleshooting.
This code is usually triggered by a defective EGR valve. The EGR valve may have a bad solenoid or carbon blockage.
In most cases, the valve is replaced which is a job that most DIYers can tackle themselves.
While it is not required, it is recommended to disconnect the battery while you replace the EGR valve. You can also clean the EGR valve but there is no guarantee that cleaning it will fix the problem.
The P0562 code can be triggered if low system voltage is detected. Along with the P0562 light, you may also get a red battery warning light on the dashboard.
Newer Dodge vehicles may even go into limp (fail safe) mode when this code is present. Low voltage can be caused by a bad alternator or voltage regulator. It can also be caused by poor ground connection, corroded battery terminals, or battery that has a bad cell.
If you read the codes and your Dodge has code P0562 address the problem as soon as possible. If ignored you may experience other problems such as engine refusing to start, poor fuel economy or transmission not shifting out of Park and into Drive.
If your Dodge check engine light is on and you get code P0404 it means that your Dodge Exhaust Gas Recirculation (EGR) valve is operating out of range.
The purpose of the EGR valve is to recirculate exhaust gases and send them back into the engine to lower the NOx emissions.
In a new Dodge EGR Valve costs anywhere from $50 to $200 and to replace it at the dealer in average you will pay between $300 and $550.
The EGR is mounted on your Dodge engine near the exhaust. In most Dodge vehicles it is fairly easy to replace.
This is a job that most DIYers can perform in their driveway as long as you have the correct tools.
Keep in mind that the EGR valve itself may not always be the problem. The problem could also be the signal from the EGR valve to the engine ECU.
This code has similar symptoms to a vacuum leak as well. Make sure to check the solenoid operation and wiring as well. You need to perform a continuity test on the wire harness to make sure the wire harness to the EGR is not defective.
Some of the most common symptoms of the P0404 on Dodge vehicles include engine dying at idle, engine stalling or rough idle. This is a common problem on Dodge trucks such as Rams where in addition to the P0404 code you may also get the P0406 code.
A P0720 code is a generic transmission code. The code indicates that there is a malfunction of the output shaft sensor. The problem could be the sensor itself or the wire harness.
Common symptoms include delayed shifting and the check engine light on. In some cases, a Dodge P0720 can also be caused by a defective transmission fluid temperature sensor.
The sensor is mounted on the side of the transmission, towards the end. Note that the output speed sensor is also used as the input speed sensor on certain Dodge transmission.
Check the current price on Dodge output speed sensor.
If your check engine light is on and you get the P0420 code it means that the catalytic converter is working below efficiency.
In most cases, the catalytic converter is the culprit but the problem could also be an oxygen sensor that is not working properly.
One symptom of being a bad catalytic converter is that the vehicle may struggle to accelerate when you press the gas pedal. When this code is present the fuel economy decreases.
This code means evaporative emission control system has incorrect purge flow. A P0441 code on Dodge vehicles is often triggered by either a faulty purge control valve, purge solenoid or damaged purge solenoid wires. This problem can be caused by restrictions on the EVAP system or bad vacuum witch.