U0634: Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor A
What Does U0634 Mean?
U0634 is a diagnostic trouble code indicating: Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor A. This code relates to the vehicle systems system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
What To Do Next
-
1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
-
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
-
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.
Related Codes
U0629
Lost Communication With A/C Refrigerant Temperature Sensor “B”
U0630
Lost Communication With Engine Coolant Temperature Sensor 4
U0631
Lost Communication With Engine Coolant Temperature Sensor 5
U0632
Lost Communication With Fan 1
U0633
Lost Communication With Fan 2
U0635
Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor B
U0636
Lost Communication With Hybrid/EV Battery Pack Coolant Control Valve A
U0637
Lost Communication With Hybrid/EV Battery Pack Coolant Control Valve B