Supercharger Session Ended Before Target SOC
What does TESLA-CHARGE_A157 mean?
The TESLA-CHARGE_A157 (Tesla) EV fault code means: Supercharger Session Ended Before Target SOC. This is a moderate severity code.
Common Symptoms
- Touchscreen shows 'Charging Stopped' or 'Unable to Charge' before your target state of charge is reached
- The charging session ends abruptly and the car does not reconnect on its own
- Charge port light pulses amber or goes solid white and then off without completing the session
- Tesla app shows a charging error notification with session ending unexpectedly
- Supercharger stall shows as in-use on the in-car map but your car is no longer drawing power
- Reduced charge rate (derate) just before the session cuts out, then full stop
- Car does not resume charging even after you tap 'Start Charging' on the touchscreen
Probable Causes (Ranked by Likelihood)
- Supercharger station-side communication timeout or stall malfunction causing the EVSE to drop the session handshake Very Likely
- Charge cable or charge port connector running above safe temperature limits, triggering a thermal protection cutoff Very Likely
- Station-side power derate due to shared cabinet load, grid fluctuation, or high stall demand at a busy site Likely
- Dirty, corroded, or damaged charge port pins on the vehicle side causing intermittent contact and handshake failure Likely
- BMS-side communication fault where the car stops acknowledging the Supercharger pilot signal, often after a failed over-the-air software update Possible
- High ambient temperature combined with a hot battery pack triggering BMS thermal derating that escalates to a full session stop Possible
- Loose or partially seated charge cable at the vehicle inlet not fully locking the latch, causing intermittent loss of the CAN link between car and station Less Likely
Step-by-Step Diagnostic Procedure
Move to a different Supercharger stall, ideally one in a different power cabinet (stalls are usually paired: 1A/1B share a cabinet, 2A/2B share another). If the new stall charges without issue, the problem is station-side and not your car.
Inspect the charge port opening with a flashlight. Look for bent, pushed-back, or corroded pins. Any visible pin damage means do not force another connection. Schedule service.
Check the charge port door and latch mechanism. The door should swing fully open and the latch should click audibly when the cable seats. A partial seat will trigger CHARGE_a157 within the first few minutes of a session.
Open the Tesla touchscreen service menu (long-press the brake pedal and the Autopilot button simultaneously on most models, or navigate to Controls > Service). Look for any active BMS or VCFRONT faults logged alongside CHARGE_a157. Use Scan My Tesla with an OBDLink MX+ or Veepeak adapter to pull the full fault log if the service menu does not show detail.
Check battery temperature on the touchscreen energy screen or in Scan My Tesla. If pack temps are above 40 degrees C before you plug in, precondition the battery for 20 to 30 minutes by setting a Supercharger as your navigation destination. The car will cool or warm the pack to an optimal charge temperature before arrival.
Try a soft reboot of the vehicle controllers: hold both scroll wheel buttons until the screen goes dark and the Tesla logo reappears (about 10 seconds). After the reboot completes, plug in again at the same stall to see if the session holds.
If the fault repeats at multiple stations or multiple stalls, connect Scan My Tesla with the OBDLink MX+ adapter and review the BMS fault log for thermal flags, cell imbalance codes, or VCFRONT communication errors that would indicate a vehicle-side repair is needed.
If pin damage is confirmed, the charge port connector is not a DIY repair on any current Tesla platform. This requires Tesla Toolbox 3 calibration after replacement and should go to a certified EV shop.
Frequently Asked Questions
What does TESLA-CHARGE_a157 mean?
It means the Supercharger ended your charging session before your car hit the state of charge you asked for. The car and station talk to each other over a CAN link the whole time you charge. When that conversation drops, either side can cut the session. CHARGE_a157 is your car logging that the session stopped unexpectedly, but it does not always mean your car is broken. The station stall, a hot cable, or a busy shared cabinet are the most common culprits.
Can I still drive the car after this code?
Yes. CHARGE_a157 is a charging session fault, not a drivetrain or battery fault. Your car will drive normally. The concern is that you may be leaving with less charge than you planned, so check your remaining range before you leave the station.
How much does it cost to fix?
If the problem is the Supercharger stall, it costs you nothing. Move stalls and retry. If it turns out to be a damaged charge port on your car, expect $400 to $700 at a Tesla service center or $350 to $550 at an independent EV shop including parts and labor. Pulling fault codes yourself with a $50 OBDLink MX+ adapter and Scan My Tesla is the smart first step before spending anything.
Will this code stop me from charging at home or at other Level 2 stations?
Usually not. CHARGE_a157 is specific to the DC fast charge Supercharger protocol. If your home Level 2 charging and destination chargers are working fine, the fault is very likely station-side or isolated to the DC charge path in the charge port. If Level 2 is also failing, that points to a vehicle-side charge port or BMS issue that needs a shop.