OBD-II code · Network
U0615 Lost Communication With Engine Coolant Bypass Valve A
The vehicle bus reports loss of communication with smart engine coolant bypass valve A. Bypass switching for thermal management cannot be commanded.
Is it safe to drive with U0615?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyBus wiring open or shorted
- PossibleModule without power or ground
- PossibleModule failed
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Coolant Bypass Valve A, Vehicle Bus Wiring
Related codes
- U0616Lost Communication With Engine Coolant Bypass Valve B
- U0617Lost Communication With Engine Coolant Bypass Valve C
- U0618Lost Communication With Engine Coolant Bypass Valve D
- U0612Lost Communication With Intake Air Temperature Sensor 1 Bank 2
- U0613Lost Communication With Intake Air Temperature Sensor 2 Bank 1
- U0614Lost Communication With Intake Air Temperature Sensor 2 Bank 2
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.