Auto start did not engage, OBD2 code P2BA3

[pinkelman]

Good afternoon everyone.
I was hoping someone might have some wisdom on my situation. My truck is a 2020 1500 with etorque. The other day I came to a stop and the auto stop/start engaged, but it did not turn the truck back on normally. When I released my foot from the brake, there was a pause and then eventually the truck started with the starter motor instead of the etorque system.

On the rest of my trip, it worked normally a few times, but malfunctioned another time with the same symptoms. It is also stuttery and shifts hard in lower gears.

I hooked it up to a scanner, and it came out with code P2BA3.

Could it really be the alternator, or do you think it might be the hybrid battery? The truck has 43k miles.

Thanks for your input!

 

[bigdodge]

https://static.nhtsa.gov/odi/tsbs/2020/MC-10176566-9999.pdf

 

[pinkelman]

https://static.nhtsa.gov/odi/tsbs/2020/MC-10176566-9999.pdf

I found this doing research - This is a belt tensioner TSB. I doubt it would cause issues with hard shifting and the etorque completely ducking out.

 

[kapinallinen2]

Not sure about the hard shifting. This is from alldatadiy.

P2BA3-00-STARTER/GENERATOR MECHANICAL PERFORMANCE​

"The HCP monitors belt slip speed by comparing the HCP resolver speed and crankshaft speed inputs and determines a belt slip condition""

Set Conditions:

• The Hybrid Control Processor (HCP) has detected a belt slip during an Auto Start event.

Default Actions:

• Malfunction Indicator Lamp (MIL) on.
• 12 volt back-up start occurs.
• Engine Stop/Start (ESS) is disabled for remainder of key cycle.

• Possible Causes​

OTHER HYBRID CONTROL PROCESSOR (HCP) DTCS

CONTAMINATED SERPENTINE BELT OR PULLEYS

SERPENTINE BELT SLIPPAGE

BELT TENSIONER NOT PROVIDING ENOUGH TENSION ON SERPENTINE BELT (TENSIONER SERVICE PIN NOT REMOVED OR WEAK TENSIONER)

INCORRECT ROUTING OF THE SERPENTINE BELT

INCORRECTLY INSTALLED SERPENTINE BELT STOP BRACKET (5.7L ONLY)

TECHNICIAN DID NOT PERFORM SCAN TOOL ROUTINE AFTER SERVICING SERPENTINE BELT AND OR BELT TENSIONER

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[MarkTTU]

I had a similar issue last week, auto stop worked and then auto start didn’t work when I took my foot off the brake. The instrument cluster also started complaining about low volts on the 12v battery and watching the voltage gauge the 12v the battery was not charging once I got going. I didn’t pull the code, but after doing some googling I decided to try replacing the 12v battery. Haven’t had the issue since.

 

[pinkelman]

I had a similar issue last week, auto stop worked and then auto start didn’t work when I took my foot off the brake. The instrument cluster also started complaining about low volts on the 12v battery and watching the voltage gauge the 12v the battery was not charging once I got going. I didn’t pull the code, but after doing some googling I decided to try replacing the 12v battery. Haven’t had the issue since.

Thank you for your input. I had considered doing the same thing. We have had some especially cold weather which can affect battery performance. The engine light turned off by itself two days ago, and started working... so I wonder if it was a combo of battery degradation and cold weather.

 

[MarkTTU]

Thank you for your input. I had considered doing the same thing. We have had some especially cold weather which can affect battery performance. The engine light turned off by itself two days ago, and started working... so I wonder if it was a combo of battery degradation and cold weather.

When it happened to me it was especially cold (for central Texas) and had been for several days. I suspect weak battery plus cold is what got me.

I’ve observed the start portion of my auto start is happening noticeably faster now than it had been the last 6 months or so. I can’t say that I noticed the speed of the auto start degrading, but I had noticed the system annoying me and me manually disabling it quite often the past 6 or so months. Immediately after installing the new 12v battery I noticed the auto start occurring more quickly.

I believe the auto start is being handled by the 48v battery, that’s kinda the whole point of the eTorque system as I understand it, so I’m not sure why replacing the 12v battery made such a dramatic difference to the speed of the auto start. My only guess is the weak battery led to weak spark during initial ignition.

 

[Paulmug1]

I had a similar issue last week, auto stop worked and then auto start didn’t work when I took my foot off the brake. The instrument cluster also started complaining about low volts on the 12v battery and watching the voltage gauge the 12v the battery was not charging once I got going. I didn’t pull the code, but after doing some googling I decided to try replacing the 12v battery. Haven’t had the issue since.

I have had the same situation twice. Stopped at red light or stop sign, engine turned of normally when lifted foot of brake engine started then stopped immediately. Put truck I park and started by pushing button. Both times battery warning light came on and voltage showed 11.7 charging. After turning vehicle completely off and restarting everything was normal. My good friend who live across the street also has a 22 ram and has had the same problem several times. I am considering installing an Autostop Eliminator. Autostop Eliminator for 2019 - 2024 RAM 1500