How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dan Your Own Question
Dan, Technician
Category: Hyundai
Satisfied Customers: 24211
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
Type Your Hyundai Question Here...
Dan is online now
A new question is answered every 9 seconds

2010 hyundia sonata 2.4 l has coolant temp -54 and iat -54

Customer Question

2010 hyundia sonata 2.4 l has coolant temp -54 and iat -54 no codes and runs rich what is issue with cts
Submitted: 1 year ago.
Category: Hyundai
Expert:  Dan replied 1 year ago.

Hello, my name is***** is actual temp outside? Have you replaced the cts yet? Thanks.

Customer: replied 1 year ago.
out side temp 68 deg. I have no codes but the cts is -54 and iat is -54 and starts good cold or hot , temp gage works good and not on cold. the cts and iat are friving me crazy . they will not move
Customer: replied 1 year ago.
my name is ***** ***** tho cts and iat are -54 there is no big drivability issues, starts good , just runs rich and uses excessive fuel. I tested iat ohms was 2.56k and 5 volt ref good and both cts and iat , ground good , but still see -54
Expert:  Dan replied 1 year ago.

Are you checking the temp readings with scantool or dash? Does cts ever change as vehicle warms up?

Customer: replied 1 year ago.
I am checking at scan tool , snap on verdict and a modius, both show -54 but yet no codes
Customer: replied 1 year ago.
no cts never changes as warms up but gage on dash goes up to half after run for a wahile
Expert:  Dan replied 1 year ago.

Neither of them share the same circuit so it sounds like problem is either your ECM or the sensor. I'd start by replacing the cts to see if that helps. If not, next step will be to check wiring between ECT and ECM, if good replace the ECM. Here is a wiring diagram to help with testing. Let me know if there is anything else I can do to help. Thanks.