Hyundai sonata code P0638

**pal006a** · 24th July, 2020, 10:50 AM

Dear all . good day . I face a problem with 2013-2014 Sonata 2.0L the DTC code P0638 ( Throttle actuator control range / performance Bank 1) .The throttle body replaced with use and new one but still same . The car start normal and pedal accelerator responds when can car cold in the morning but after warm i have to first keep car start button on ( ON ) mode with out starting for few seconds than start to gets pedal accelerator responds . If you starts the car directly with out waiting On (ON) mode will not start .please help need help .
Hyundai sonata code.jpg

**Meat-Head** · 25th July, 2020, 05:41 PM

A) ecu software see dealer
b) reset adaptations
c) it’s possessed

**pal006a** · 28th July, 2020, 06:38 AM

I will try to reflash ECU today . reset adaptations tried but no changes same problem .

**pal006a** · 28th July, 2020, 07:21 AM

Originally Posted by Meat-Head

A) ecu software see dealer
b) reset adaptations
c) it’s possessed

I will try to reflash ECU today . reset adaptations tried but no changes same problem .

**RBAautomotive** · 14th March, 2021, 11:55 PM

Best, I have the same problem, have you solved this problem?

**RBAautomotive** · 15th March, 2021, 06:14 PM

Dear colleagues, does anyone have an idea about the above problem?

**Subix** · 5th January, 2022, 09:17 PM

Any solution found?

**huwalsh** · 14th January, 2022, 06:22 PM

not come accross this myself but are you loosing 5V or ground at throttle motor check all signals but sounds like ecu issue

**Subix** · 17th January, 2022, 02:50 PM

Originally Posted by huwalsh

not come accross this myself but are you loosing 5V or ground at throttle motor check all signals but sounds like ecu issue

yep ecu startup check throw foult code ,test shows etc motor duty -99.997 ,tps 1&2 ok. adaptation learning works only one time start or if engine abowe 40'C and you wait for fev seconds with ignition on and then start cranking its randomly ok.on cold engine throw fault every time (cant erase code until engine warms up ) throttle lelearn manual and software seems to not working or lost after ignition off. Wiring to throttle body checked ok. no visual damage to ecu board, plan to replace ecu next or reflash

**rui** · 17th January, 2022, 11:48 PM

By chance, have you already checked the lambda probe relay (open it and see if there is no cracked solder) if the cold works well and when it is hot the engine does that.
I've had a car with similar symptoms and it was the relay.

**Subix** · 11th February, 2022, 05:35 PM

update: ecu stuck in "learn mode "or loosing memory (dtc p0638 stays historic and pending),ecu replacement cloning same symptoms stays.

**Karollll** · 12th February, 2022, 10:39 AM

Please check schematIC diagram and then wiring, maybe this some help you...

**Subix** · 14th February, 2022, 10:42 AM

wiring seems to be ok, checked that firs bypassed main relay acording to diagram lambda is conncted to it (car works fully ok when warmed up and throttle learned at start,if you wait 5 seconds before crank ) problem is car does not record it properly i think .adaptation values reset and manufactures procedure wont work/end properly and save.at this point traying to resolve without dtc off. updated ecu software or more likely virgin ecu data may help.

**thunderwinged 2** · 12th January, 2023, 06:44 PM

Originally Posted by Subix

wiring seems to be ok, checked that firs bypassed main relay acording to diagram lambda is conncted to it (car works fully ok when warmed up and throttle learned at start,if you wait 5 seconds before crank ) problem is car does not record it properly i think .adaptation values reset and manufactures procedure wont work/end properly and save.at this point traying to resolve without dtc off. updated ecu software or more likely virgin ecu data may help.

hi i have same problem any solution founded?