P0A9C Error: '21 Sahara 3.6 E*Torque

[waypoint]

We're at 14K miles on our '21 Sahara w/ 3.6L E*Torque and auto trans. On Memorial Day Monday, one year anniversary of our order date, the Check Engine light lit and scanner showed P0A9C "Hybrid battery temperature sensor A range/performance". Ambient temp was in the mid-'80F range and we've driven it in hotter temps without issue thus far.

I took it to the dealer this morning for this and a spongy-feeling brake pedal compared to our other vehicles, they flagged it as needing an ECU flash update in addition to my two concerns.

Anybody encountered this error code?

I'll update on our outcome.

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[waypoint]

Update: I've called twice and been on hold for 15 minutes plus before getting transferred to a dead voicemail box. Finally got through to the service advisor right before 5pm closing time, they've opened a Star Case and are halted for the day awaiting approval to do things. No findings as to the cause or corrective action.

Jeep Wave says they will reimburse for a rental car.

 

[waypoint]

Update (Day 2): the problem can not be reproduced. The error code is still stored in Confirmed as well as Permanent states, so there's no dispute that it occurred. Just can't get it to happen again.

Shop has run diagnostics, verified grounds and voltage at connector pins, sent data to Corporate with a request to replace the high voltage battery & controller module assembly mounted on the underside of the floorpan. Awaiting response from Corp as of Wed evening.

The outcome tomorrow will be either a replacement part shipped from the factory, or no replacement and bring the Jeep back if the error repeats. We get the Jeep back either way as it's safe to drive, a failure of the assembly will simply deactivate E*Torque and auto stop/start.

It will also get a firmware update which was indicated, unrelated to the error code. I'll try to learn more about the reason for the update.

 

[demarpaint]

I wouldn't be happy if they can't fix it, and I'd make sure they did. But not having eTorque or Stop/Start would be a plus for me as I wouldn't have to disable it every time I got into my Jeep, or pay for a dongle to do it for me. Flame suit on........

 

[waypoint]

Day 3: Replacement high voltage battery module has been approved and is being shipped, picked up the Jeep last night and returned the rental car. New part should arrive mid-month.

PCM firmware update was listed as RRT 21-139 2021 JL PCM Update, no details on what it fixes.

 

[waypoint]

Yeah, I was debating installing an ESS eliminator as I don't like it either. Glad now that I didn't or it's likely they might have assigned fault for the error, and I'd have no certainty either way.

It's my wife's daily driver and she doesn't mind it, the restart is so smooth it's barely noticeable.

I wouldn't be happy if they can't fix it, and I'd make sure they did. But not having eTorque or Stop/Start would be a plus for me as I wouldn't have to disable it every time I got into my Jeep, or pay for a dongle to do it for me. Flame suit on........

 

[Gunfighter]

No issues with ours. I have a TAZR and have the ESS turned off via default.

 

[waypoint]

If it was my daily driver, I'd do the same.

No issues with ours. I have a TAZR and have the ESS turned off via default.

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