2011 Hyundai Sonata Hybrid - READY Light Flashing, No Acceleration, DTC P1744
Hello everyone,
I'm trying to diagnose a persistent issue with my 2011 Hyundai Sonata Hybrid and would really appreciate any advice from those familiar with Hyundai hybrid systems.
Vehicle Information
Model: 2011 Hyundai Sonata Hybrid
Mileage: 114,000 km (approximately 71,000 miles)
Symptoms
The problem usually appears after 10–20 minutes of driving.
The READY indicator starts flashing.
The gasoline engine continues running normally.
Pressing the accelerator causes the engine RPM to increase, but the vehicle barely accelerates.
The car continues moving very slowly, as if it is relying mainly on the electric motor.
On the energy flow display, power flows from the gasoline engine to the hybrid battery only, not from the engine to the wheels.
If I stop the car and shift to P, the engine charges the hybrid battery normally.
After waiting about 3–6 minutes, the READY light stops flashing and the vehicle drives normally again.
However, the problem returns after a short time.
Additional Observation
One strange thing I've noticed:
If I keep engine RPM above approximately 4,000, the READY light usually does not start flashing.
The problem tends to occur when engine RPM is between 2,000 and 3,500 under moderate acceleration.
What Has Already Been Checked
Hybrid battery cell voltages were tested recently.
Voltage difference between cells is only about 0.04 V.
Battery temperatures are normal.
No hybrid battery DTCs were found.
Transmission fluid and transmission filter were replaced about 6 months ago, but the problem remained exactly the same.
Diagnostic Trouble Code
The only significant code found is:
P1744 – Engine Clutch System Performance
Transmission Behavior
No harsh shifting.
No delay when selecting D or R.
No noticeable vibration or noise.
The problem only affects acceleration after READY begins flashing.
My Question
Based on these symptoms and the P1744 code, would you suspect:
Engine clutch wear?
Clutch actuator failure?
Clutch position sensor?
Wiring/connectors?
HPCU/TCU issue?
Something else?
Has anyone experienced this exact problem on a 2011–2015 Sonata Hybrid?
Any diagnostic advice or known fixes would be greatly appreciated.
Thank you!
Hello everyone,
I'm trying to diagnose a persistent issue with my 2011 Hyundai Sonata Hybrid and would really appreciate any advice from those familiar with Hyundai hybrid systems.
Vehicle Information
Model: 2011 Hyundai Sonata Hybrid
Mileage: 114,000 km (approximately 71,000 miles)
Symptoms
The problem usually appears after 10–20 minutes of driving.
The READY indicator starts flashing.
The gasoline engine continues running normally.
Pressing the accelerator causes the engine RPM to increase, but the vehicle barely accelerates.
The car continues moving very slowly, as if it is relying mainly on the electric motor.
On the energy flow display, power flows from the gasoline engine to the hybrid battery only, not from the engine to the wheels.
If I stop the car and shift to P, the engine charges the hybrid battery normally.
After waiting about 3–6 minutes, the READY light stops flashing and the vehicle drives normally again.
However, the problem returns after a short time.
Additional Observation
One strange thing I've noticed:
If I keep engine RPM above approximately 4,000, the READY light usually does not start flashing.
The problem tends to occur when engine RPM is between 2,000 and 3,500 under moderate acceleration.
What Has Already Been Checked
Hybrid battery cell voltages were tested recently.
Voltage difference between cells is only about 0.04 V.
Battery temperatures are normal.
No hybrid battery DTCs were found.
Transmission fluid and transmission filter were replaced about 6 months ago, but the problem remained exactly the same.
Diagnostic Trouble Code
The only significant code found is:
P1744 – Engine Clutch System Performance
Transmission Behavior
No harsh shifting.
No delay when selecting D or R.
No noticeable vibration or noise.
The problem only affects acceleration after READY begins flashing.
My Question
Based on these symptoms and the P1744 code, would you suspect:
Engine clutch wear?
Clutch actuator failure?
Clutch position sensor?
Wiring/connectors?
HPCU/TCU issue?
Something else?
Has anyone experienced this exact problem on a 2011–2015 Sonata Hybrid?
Any diagnostic advice or known fixes would be greatly appreciated.
Thank you!