Hondata

Good afternoon All,

Details of car:
- 02 RSX-S with JRSC K24A2 + w/m (details in sig). Also, no thermostat.
- Not sure of serial number, but K-Pro v3
- KManager 4.4.1
- See attached .kal
- See attached .kdls
- Purchased kpro back in 2011 via kseriesparts.com/clubrsx (authorized dealer) who worked directly with Hondata to upgrade my stock ECU
- Car hesitates/bogs during mid to hard acceleration, then throws Error: Daughter board communication error (battery voltage low when cranking)

This issue started about 2 weeks ago. Car has been bogging or cutting fuel during medium to hard acceleration. At first, I thought it was due to low fuel (happens when I have less than 1/4 tank), but it's happening with full tank as well and all the time now.

First, I noticed that the battery voltage read 14.2 to 12v cycling every minute. I re-did the ground points and checked the positive connection to the alternator. Tested the alternator, turned on everything accessory, headlights, radio, A/C, datalogged and the battery stayed between 13.6-14.2v. Towards the end, I did a WOT 3rd gear pull while spraying 50/50 W/M at 1000cc/min and it bogged out (3rdGearWOT_BogW_WM_20apr19.kdl).

I then attempted again today without any W/M injection. I did a 3rd gear pull and the car bogged again (3rdGearWOT_Bog_noWM_21apr19.kdl). At first, I thought it was do to the W/M spraying too much; however, I don't believe this is the issue as I've been running this setup since Jan 2018 with zero issues.

Any help would be greatly appreciated!

V/R, Nats

GM,

More information. I loaded an old tune (same as the one attached pre W/M injection) this morning and datalog. Car felt fine. I didn't get on it, turned off W/M, and just drove normal. I experienced the bog around 10 mins into the ride.

Reviewing the datalog shows:
Frame 3866
Rpm 3331
Map -5.6
A/F 14.27
TPS 23%
IGN 29*
Kcount 0
ECT 174*
IAT 127*
VSS 25mph
Gear 2
Batt 14v

Frame 3867
Rpm 0
Map -29.9
A/F 689.6
TPS -10%
IGN -64*
Kcount 0
ECT 174*
IAT 127*
VSS 0mph
Gear 0
Batt 14v

Frame 3868
Rpm 3757
Map -15.6
A/F 10.77
TPS 0%
IGN 44*
Kcount 0
ECT 174*
IAT 127*
VSS 26mph
Gear 2
Batt 14v

MIL came on about 90 secs after this. I know believe the issue is no longer the tune. Injectors reading was way off. Any advice?

What is the serial number that is on the K-Pro board inside the ECU?

Spunkster wrote: Mon Apr 22, 2019 9:43 am What is the serial number that is on the K-Pro board inside the ECU?

On ECU:
37820-PRB-A05
2068-503598-0L24

Hand writing next to above number is 230

On K-Pro board (K-Pro-III r19):

Silver sticker KP-Pro 11230

V/R, Nats

I would suggest that you try your ECU in a different vehicle to see if the problem follows the ECU or is only with your vehicle.

Spunkster wrote: Tue Apr 23, 2019 9:15 am I would suggest that you try your ECU in a different vehicle to see if the problem follows the ECU or is only with your vehicle.

Ugh... That's going to be tough. Not a lot of RSXs still around that I know locally, especially with my mods. I'm tuned for a K24a2 +JRSC (baseline). I guess you are saying put ECU in another car and load a tune for that car and see what happens?

If it's not the ECU, any other suggestions to diagnose? Have you seen this problem before with random bogs and AFRs jumping like that?

Another thought... I deleted my power steering in 2017. I still have the OEM rack, but the PS pressure switch is not connected to anything. Will this cause a problem? I reviewed my datalogs and it doesn't seem to be, but figured it's worth asking.

I went back and verified connections to ECU are solid to include my W/M connections to E22 (arming input) and E21 (output control).

That should not have anything to do with this.

Spunkster wrote: Mon Apr 29, 2019 10:50 am That should not have anything to do with this.

Thanks! So it looks like I have another colleague on ClubRSX experiencing similar issues and getting the same symptoms. He's running kpro v1 and attributed it to the older version of kpro.

Do you think if I upgrade to kpro v4, this will rectify my issue?

I'm at a loss now cause the car bog/bucks even with me babying it. Happened 3x this morning and reviewing the datalog, battery voltage is 14.0-14.2v the entire time despite the error message.

Send an email to support <at> Hondata.com with the following and I will issue an RMA and give you further
instructions:

Name:
Address:
Phone:
Email:
Serial#:
description of problem:

include a link to this thread.

Spunkster wrote: Tue Apr 30, 2019 9:55 am Send an email to support <at> Hondata.com with the following and I will issue an RMA and give you further
instructions:

Name:
Address:
Phone:
Email:
Serial#:
description of problem:

include a link to this thread.

Thank you! Email has been sent. VR, Nats

Update: issue seems to be resolved. I ended up changing the original TPS sensor to an Acuity. I noticed in the datalogs, when the bogging happened, the TPS dropped below -10. I ended up changing the TPS and servicing my TB. Car is driveable again!

Has the daughter board connection error bee. Resolved after you change tps?