I just bought a used 2017 Prius Prime and was going through the service records on Toyota’s site (the previous owner took advantage of the mo-cost maintenance and was early for each 5k mile service). Just before they sold the car, they brought it in for P0A1F94 with the following info: REPROGRAM BECM ~|~CUSTOMER STATES GUEST STATES CHECK ENGINE LILGHT WAS OCCURING SCAN AND PERFORM HEALTH CHECK AND ADVISE. ~|~. ~|~55718 HAS CODE P0A1F94. EV BATTERY ENERGY CONTROL UNEXPECTED OPERATION. EL1905 80 REPROGRAMMED BECM OP CODE EL1905 T1 8A T2 74 The work was covered as warranty repair. Googling about the code pointed me to T-SB-0032-19 Revision 1 which covers that code 100k miles / 96 months (based on the comment I read regarding it). I couldn’t actually find a copy of that TSB to read the details of what is going on with the system though. Does anyone know if this is just a BECM reprogram issue that is resolved with the update or if this is something I could potentially trigger again in the future? A quick search of the forum didn’t come back with any results for this code.
Bulletin T-SB-0032-19 Rev1, “MIL ON DTC P0A1F94” (PDF), June 17, 2019, is posted on NHTSA’s website. I found it there by searching Google for site:nhtsa.gov "T-SB-0032-19". The Repair Manual (more info) procedure for DTC P0A1F94 says to replace the battery ECU assembly (battery energy control module); the bulletin alters that procedure to update its software instead, if that hasn’t already been done. If the update has been applied correctly, I’d be surprised if the trouble were to return.
