U064A code meaning
Lost Communication With Hybrid/EV Battery Pack Current Sensor A
Network system Generic code U06xx codes Check engine light
What U064A means
Battery management needs the pack current to count charge in and out and to judge state of charge and state of health. Many packs measure it with a self-contained sensor that sends its value over CAN; LEM's CAB series, for example, transmits on high-speed CAN at 500 kbit/s and is built for ASIL C. U064A records that current sensor A has stopped sending, while an analog sensor would report wiring faults via P0ABF to P0AC3. No manufacturer documents U064A publicly. CARB 1968.2 (e)(15.2.3)(A)(iv) requires the electronic inputs of the energy storage system to be monitored, which on hybrids points to a lit MIL. Without a current value the battery controller cannot track charge and normally restricts charging and discharging sharply.
U064A at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U064A
- Hybrid or EV battery warning, on hybrids also the MIL
- Strongly reduced drive power or charging refused
- Implausible state-of-charge display
Common causes of U064A
- PossibleCAN, supply or ground wiring of sensor A inside or at the pack damaged
- PossibleCurrent sensor A failed
- PossibleMoisture or corrosion at the pack's low-voltage connector
- Less likelyBattery energy control module fault or software
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery current sensor aVehicle bus wiring
What each part of U064A means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4A | The exact fault in that area. |
What to do next
- Note U064A and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U064A
What does U064A mean?
U064A means "Lost Communication With Hybrid/EV Battery Pack Current Sensor A". Battery management needs the pack current to count charge in and out and to judge state of charge and state of health. It is a generic code, so it means the same on every make.
Is it safe to drive with U064A?
Drive gently and only to a workshop. With U064A the car can go into limp mode (reduced power) to protect itself.
Will U064A fail an emissions test?
Yes, it can. U064A is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is U064A to fix?
Difficulty: workshop only. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U064A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.