Hondata

I ahve a customer that brought me a car (in pieces of course) to get it straightened out. it's a
97 civic
H22 swap
obd1 pcm (have tried both P28 and P72)
obd1-2 swap harness
S300. serial number s300-5383
3bar MSD map sensor
AEM wideband

The issue is this, I have updated all software (I just installed it to tune his car) and the PCm is reporting 0kpa MAP and it's unresponsive.
Same thing with the O2 feed. It reports 3.8V, yet there is ZERO volts going to the pin.
All other A/d channels operate correctly.

I have gone thru the wiring harness extensively, all is correct. I have traced voltage all the way back to the A/D section and signial condtioners on 2 different pcm boards.
The MAp sensor pin is recieving 1.7 v KEO, and should be reading about 100kpa. It reads 0kpa as though there were nothing going to it.
The O2 sensor pin is recieving 0.1v and is reporting 3.8V.

It is the same with 2 different pcm's.

It's beginning to point to the S300. any ideas? Did I miss something?

Please help.

So I guess Im the only one that this has come across this issue?? DOH!

I wonder what the hell is going on there? If a chase 1.6V right up to the input Cap, how the hell is it reading ZERO on Smanager?
Same with the O2 situation, 0.1V right up tot he input cap, but it reads 3.8V in the Smanager? how is this possible in 2 different PCMs?


Help me Obi-Wan hondata, your my only hope!

I just installed the PCM into a known working OBD1 car and it still is Malfuctioning the same way.

So to retiterate
2pcm's
2cars

no map signal and 3.81v in the O2 slot. All other sensors fuction properly.

WTF? can it be anything other than the S300 itself? software bug? any known issues?

Has the firmware been updated on the ECU? any problems getting S300 to communicate with Smanager in any other way?

The update firmware is grey'd out. Do I have to jumper or something?
I dont have it plugged into the car right now But I beleive it said the firmware was 1.07?

Can you provide the calibration you are using and a datalog showing the problem?

I can, But I can tell you it's merely one of the provided stock calibrations for a P28 with the Injector constant changed,and MSD3 bar map sensor selscted.
There really isnt any datalog other than a "normal" obd1 pcm that's key on engine off.
MAp sensor reads zero KPA instead of ambient pressure
O2 voltage is stuck at 3.8V no matter what I change the input feed from (O2,ERGL,etc)

I have used a 5v jumper to try to get the map to peg at 300 kpa. zero change.


Thanks for the input everyone!

Have you tried starting the car and datalogging?

Wont run long without map sensor. runs only if you get the afr right via TPS. MAP doenst read.


Well I just finished re-socketing the 1st PCM for a normal chip and installed crome/Freelog. guess what. Reports correct voltage from the MAP and O2.
Starts and runs.
So at this point there can be no doubt there is somethign wrong with this guy's S300. It talks to the PCM fine and operates fine in evey other way, just doesnt read anything coming from the MAP sensor address and reads from what looks like to be the ELD adress for O2 voltage.
Software/OS issue.

Now how do we fix it.


Thankyou for your replies BTW, all I got from "tech support" is "did you try it in another car?" Nothing since.

Please try starting the car and datalog and see if hte map sensor reads properly. I just tested and with the key in only the on positoin it reads full vacuum (29.5 inches of vacuum). I do not believe there is any problem at this point.

you were totally right on the map sensor! I dont understand what the purpose could be of having the MAP sensor not sample during KEO, when nearly all others do? Weird!

Thanks a bunch on that one. I was going system by system on the car before running it and the MAP zero was a red flag for me.

O2 sensor is still not reading anythign other than 3.8V. But were' getting someplace!

FWIW this little tidbit should be in the sticky! It would have saved me ALOT of time and effort.

Baldturbofreak.com wrote:you were totally right on the map sensor! I dont understand what the purpose could be of having the MAP sensor not sample during KEO, when nearly all others do? Weird!

Thanks a bunch on that one. I was going system by system on the car before running it and the MAP zero was a red flag for me.

O2 sensor is still not reading anythign other than 3.8V. But were' getting someplace!

did you input your specific widebands voltages into your wideband table and did you select AFR instead of lambda in the settings for display?