Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.
If the engine light is flashing this is indicating a fault is detected by the engine computer.Usually a flashing engine light is an engine misfire but in this case this does sound transmission related.
What has to be done from here is to have the fault codes read out/checked with a fully compatible scan tool to see what codes are set.Once this is done any codes set need diagnosed to help locate and repair this issue here.
I suspect an issue with either the throttle position sensor or a solenoid in the transmission valve body at fault or the valve body itself.You will need to have the codes read out to see what codes are set and those codes diagnosed and repaired.
In some cases you can get the codes read out at no charge to you at a local parts store but usually they will not be able to diagnose the codes.The codes need diagnosed by a repair facility.You can also post the code info here and I can look it up for you.
If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.