100% Free

No Scanner Needed

Carly logo

Princemykah24

Persistent Issues with Hyundai Sonata: Engine and Transmission Troubles

Shaking while idling

|

Transmission slips/shifts erratically

|

Poor fuel economy

|

Engine hard to start

|

Unsteady engine

|

Check engine light on

I have a Hyundai Sonata and I'm experiencing several issues including difficulty starting the engine, an unsteady engine, shaking while idling, poor fuel economy, and erratic transmission slips/shifts. The check engine light is also on. Interestingly, these problems persisted even after I replaced the engine. What could be the possible solutions to these issues?

5 comment(s)


CarlyMechanic

It sounds like your Hyundai Sonata might have a faulty Mass Air Flow (MAF) sensor or a malfunctioning transmission. However, let's start with the easiest check. Try to read the error codes from the car's computer using an OBD-II scanner. This will give you a clearer picture of what might be causing these issues. Once you've done that, please share the error codes here so we can help you further. Remember, if the issue persists, it's always safer to have a professional mechanic inspect your car.

Princemykah24 (Author)

@CarlyMechanic

It sounds like your Hyundai Sonata might have a faulty Mass Air Flow (MAF) sensor or a malfunctioning transmission. However, let's start with the easiest check. Try to read the error codes from the car's computer using an OBD-II scanner. This will give you a clearer picture of what might be causing these issues. Once you've done that, please share the error codes here so we can help you further. Remember, if the issue persists, it's always safer to have a professional mechanic inspect your car.

Thank you for tour swift response. The OBD II result are listed below: P0030 P0037 P0113 P0031 P0335 P0480 P0553 P1111 P0603 U2001 P803 Thank you once again.

Best Answer

CarlyMechanic

@Princemykah24

Thank you for tour swift response. The OBD II result are listed below: P0030 P0037 P0113 P0031 P0335 P0480 P0553 P1111 P0603 U2001 P803 Thank you once again.

Thanks for sharing the error codes. These codes indicate several issues including problems with the oxygen sensor heater control circuit, intake air temperature sensor, crankshaft position sensor, cooling fan, power steering pressure sensor, and possibly some others. However, let's start with the P0335 code, which is related to the crankshaft position sensor. This sensor plays a crucial role in engine management, affecting the ignition timing and fuel injection. A faulty crankshaft position sensor can cause difficulty starting the engine, unsteady engine, and poor fuel economy. I recommend replacing the crankshaft position sensor and then clearing the codes to see if any of the other codes come back. If they do, we can then address those. Please update us on your progress. Remember, if you're not comfortable doing this yourself, it's best to have a professional mechanic handle it.

Princemykah24 (Author)

@Princemykah24

Thank you for tour swift response. The OBD II result are listed below: P0030 P0037 P0113 P0031 P0335 P0480 P0553 P1111 P0603 U2001 P803 Thank you once again.

Thank for attending to my concern. It is highly appreciated. I replaced the crankshaft position sensor as advised. The car now start easily and the shaking has reduced greatly. So, after clearing the CEL, and drove for a short distance, the below codes were displayed: P0037 P0113 P0154 P0031 P0140 P0480 P0553 P1111 P0801 U2011 U20FF Thank you.

CarlyMechanic

@Princemykah24

Thank for attending to my concern. It is highly appreciated. I replaced the crankshaft position sensor as advised. The car now start easily and the shaking has reduced greatly. So, after clearing the CEL, and drove for a short distance, the below codes were displayed: P0037 P0113 P0154 P0031 P0140 P0480 P0553 P1111 P0801 U2011 U20FF Thank you.

Great to hear that replacing the crankshaft position sensor improved some of the issues. Now, let's address the P0480 code, which is related to the cooling fan control circuit. This could be due to a faulty cooling fan, relay, or control unit. Start by checking the cooling fan for any visible damage. If it looks fine, test the fan by connecting it directly to the battery. If the fan doesn't run, it needs to be replaced. If it does, the problem might be with the relay or control unit. Please proceed with these checks and let us know the outcome. Remember, if you're not comfortable doing this yourself, it's best to have a professional mechanic handle it.

Let our mechanics help you!

Do you have a problem with your car?

Let us help you free of charge!

Car Brands
carly-logo

© 2025 Carly Solutions GmbH & Co. KG. All rights reserved