Hondata

I’ve had this problem quite a few times now, normally after a longer highway drive. I’ll stop at a stoplight and notice my AFR go lean. I check my s.trim on my phone and it will be stuck at some random number, today was 1.56%.

I made it home but it wasn’t adjusting s.trim anymore and my AFR was very lean. Once I turned the car off and back on it started working properly again.

I’ll try getting a datalog when I can, but it’s random and I don’t drive around with my laptop plugged in. Is this a common problem or any ideas what might be causing it?

What is the serial number on the s300 board inside the ECU?

From Help, About, what is the version of software you are using?

39275

2.6.6.0

Has J12 been cut inside the ECU?

Yes

Post your calibration as well as a datalog showing the issue.

Did you ever get this sorted out? I've been having the exact issue.

I have this issue too... Except it always sticks at 2%

Sokoto wrote: Fri Aug 30, 2024 9:13 pm I have this issue too... Except it always sticks at 2%

Read the “closed loop malfunction” thread, plenty of people have the same issue and no fix from Hondata in years. Doubt they will ever do anything about it honestly. Just shut the car off and turn it back on and hope it doesn’t happen again any time soon at least. Seems to happen to most people on deceleration when the wideband goes full lean.

Sokoto wrote: Fri Aug 30, 2024 9:13 pm I have this issue too... Except it always sticks at 2%

Sounds like they have now implemented something to help minimize this issue in the new version v2.8.8. The closed loop inactivity timeout value can be adjusted up to around 10-11 mins (max I was able to enter is 655 seconds) which should pretty much take care of the problem as long as your S.Trim changes values rich-lean within that inactivity period it shouldn't get disabled/freeze anymore. Hondata posted a comment in one of the other threads about this issue.

Now if only we could get a fix for the "hot restart lean" issue, we need a way to add ~10-15% extra fuel but only on hot restart and for a set duration maybe 15-30 seconds or just until the closed loop can start compensating, something like that.

Good news. It def freezes less now... What I've gathered on that hot start issue, is that while the wideband is heating, it's giving a voltage reading that translates to sub 9 af ratios... My reading is like 2s-4s... At the same time, the ecu will be trying to pull fuel as much as the s.trim minimum setting allows.... In my case -12%