Hondata

I have s300 installed in a P06 modified to a P28. I am not getting a bat reading in the sensors window. Should I be getting a bat reading?

You should if everything else is reading. Post the calibration and datalog showing the problem.

Here is the calibration and a datalog.

2000 Prelude non-sh with JRSC.
P06 ECU modified to P28 serial no. 37820-P06-A52 741-710395 AUK J12 has been cut
obd2 to obd1 conversion harness
S300 serial no. S300-7628
Smanager V1-4-1 on windows xp laptop
PLX AFR with gauge.
RC 550 injectors

Attached is the calibration we used, and a datalog. As you can see, bat is reading 0 volts. After running for a few seconds, less than half a minute, Smanager freezes up. That’s why the datalog is short.

The a/f gauge is not reading properly, It is reading .9 instead of a 3 digit number. I will be checking with PLX today. I bought the plx afr directly from them. I turned closed loop on and off, also eld in misc to see if that would make any difference, it didn’t, other than the car would go very rich when in open loop.

Any ideas as to what is wrong? The ecu is out of the car, so if there is a pin to check on the harness I can do that quickly.

History. This is a project to replace the JRSC emu with a Hondata S300. All components for the S300 were purchased new within the last 2 weeks. The ecu was chipped and S300 installed by a supposed professional. The new injectors were installed along with the removal of the jrsc emu and associated rewiring back to stock of the ecu harness. The JRSC afpr was removed. The only problem we had during the installation was that we couldn’t get the old o2 sensor out. After installation of the new parts and ecu, the car started on the first try. It was driven approximately 10 miles on Monday to get to a shop to have the o2 sensor freed up. The plx afr was added last night with the installation of the wideband o2 sensor. The car has not been driven since adding the plx, only idle for a minute or two at a time.

We cut d14 on the ecu adapter harness, and wired the narrow band output of the plx to the ecu side of the harness. We cut d10 of the ecu adapter harness and wired the wideband output of the plx to the ecu side of the harness. All wiring changes have been soldered and shrink tubed. All wiring work has been double checked for accuracy, and is correct.

Any help would be greatly appreciated.

uncledan

This sounds like there may be a problem with the ECU. Try putting the ECU into another OBD1 Honda and see if the problem persists. IF it does, it is the ECU, if it does not, then it is the wiring in the car that is causing the problem.

Okay, I have a 95 Accord EX that I can plug the ecu into.

Can you tell me this? The adapter harness I bought is supposed to be obd2a to obd1. But when comparing the pinouts on the obd2 side, pin A25 is supposed to be VREF-reference voltage, but that pin on my harness is empty? Could that be why I don't have a bat reading?

One thing at a time. Try the ECU in a different vehicle.

We tried the p28 in a 95 accord coupe. It didn't work. For whatever reason, we were not able to go online with the ecu when it was connected to the car. We also tried my other Honda Accord coupe, but it is obd2b not obd2a, so the conversion harness we have won't work. We don't know anyone with another Honda that we could try on.

So, I would ask again. The adapter harness I bought is supposed to be obd2a to obd1. But when comparing the pinouts on the obd2 side, pin A25 is supposed to be VREF-reference voltage, but that pin on my harness is empty? Could that be why I don't have a bat reading?

Even though not successful to this point, thank you for your time and assistance, it is much appreciated.

uncledan

A25 is only for automatics, and is not needed. If you do not get a bat voltage reading on another car then it sounds like a problem with the ECU. Try socketing another ECU and see if the problem is resolved.

Took the ECU to an authorized Hondata dealer. They determined that while the ecu tests okay with the Hondata led tester, it is a malfunctioniong ecu. they hooked it up to another car and got no bat reading in the sensors window, and the car would start to run rich after a minute or two. So, bought another P28 that they modified for me right then and there.

If I am using D10 eld pin for wideband o2 from a PLX afr sensor module, does parameters>misc>disable eld get checked or unchecked?

Also, in the sensors window will narrowband input appear as o2 volts and wideband appear as eld volts?

uncledan