U01A7 code meaning
Lost Communication With Hybrid/EV Battery Interface Control Module H
Network system Generic code U01xx codes Check engine light
What U01A7 means
U01A7 refers to battery interface control module H. On packs with exactly eight boards it is the tail of the chain: the GM plug-in hybrid tables for 2016 to 2019 stop at U01A7, and both Audi bulletins (A3 Sportback e-tron 2016, Q5 e 2022 and 2024) list precisely U01A000 to U01A700. Since the master always names the first board it cannot reach, H on its own excludes a break further up; the cause sits in H itself, its supply or the final link leading to it. A fault earlier in the chain shows up as a lower letter, even though H then falls silent as well. GM's 2016 table requires 5 s above 10.2 V and rates the fault Type A, so the MIL lights on the first trip; 2018 to 2019 the time is 4.5 s.
U01A7 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U01A7
- MIL on the first trip (GM Type A)
- Electrical system or hybrid warning, power reduced
- All other module letters report normally
Common causes of U01A7
- Most likelyFinal chain link from module G to module H interrupted
- PossibleBattery interface control module H defective
- Less likelyTermination or return line at the end of the chain faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery interface module hCommunication bus
What each part of U01A7 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A7 | The exact fault in that area. |
What to do next
- Note U01A7 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 U01A7
What does U01A7 mean?
U01A7 means "Lost Communication With Hybrid/EV Battery Interface Control Module H". U01A7 refers to battery interface control module H. It is a generic code, so it means the same on every make.
Is it safe to drive with U01A7?
Drive gently and only to a workshop. With U01A7 the car can go into limp mode (reduced power) to protect itself.
Will U01A7 fail an emissions test?
Yes, it can. U01A7 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 U01A7 to fix?
Difficulty: workshop only. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will U01A7 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.