Network
generic / SAE
U0638
Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor A
The vehicle bus reports loss of communication with smart HV power-electronics coolant temperature sensor A. Inverter/DC-DC cooling switches to a substitute value; derating may follow.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number6 / 38
Possible causes
- Bus wiring open or shorted high
- Module without power or ground medium
- Module failed medium
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
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
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References
sae:J2012