U0635: Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor B
Severity
Medium
System
Vehicle Systems
What Does U0635 Mean?
U0635 is a diagnostic trouble code indicating: Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor B. This code relates to the vehicle systems system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Symptoms of U0635
- ⚠️ Check Engine Light (MIL) illuminated
- ⚠️ No communication with Hybrid/EV Battery Pack Coolant Temperature Sensor B
- ⚠️ Multiple warning lights may illuminate simultaneously
- ⚠️ Related system completely inoperative
- ⚠️ System warning light illuminated
Common Causes
- 🔍 CAN bus wiring fault (open or shorted) to Hybrid/EV Battery Pack Coolant Temperature Sensor B
- 🔍 Power or ground supply issue to Hybrid/EV Battery Pack Coolant Temperature Sensor B
- 🔍 Hybrid/EV Battery Pack Coolant Temperature Sensor B internal failure
- 🔍 Water intrusion damaging module or connectors
- 🔍 CAN bus termination resistor fault
Frequently Asked Questions
What does U0635 mean?
U0635 indicates: Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor B. The vehicle's computer has detected that the Hybrid/EV Battery Pack Coolant Temperature Sensor B is not operating within its expected parameters and stored this diagnostic trouble code.
Can I drive with code U0635?
You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with U0635 for extended periods may cause additional problems.
How much does it cost to fix U0635?
Repair costs for U0635 typically range from $80 to $800, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.
What To Do Next
Possible Fixes
- 🔧 Inspect CAN bus wiring to Hybrid/EV Battery Pack Coolant Temperature Sensor B for damage
- 🔧 Check power and ground supply to Hybrid/EV Battery Pack Coolant Temperature Sensor B
- 🔧 Replace failed Hybrid/EV Battery Pack Coolant Temperature Sensor B
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.
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