Hondata

Hi guys, i'm having problem with my vtec. I have a 99 ex civic coupe, with a d16y8 supercharged, cams, valves, etc..... i bought the s300, a p28 ecu and the adapting harness from importparts.com. Since the first time that i ran the ecu, it gave me the VTS code (21).

I have made all the measurements that it reviews the honda service manual. Between the selenoid terminal and ground (15 ohm), between the valve harness and the ecu pinouts (i have continuity), between the vtec harness and ground (i have no continuity, like shoul'd be), clean the vtec valve filter, tested the vtec selenoid directly from the batery to the selenoid. With the car running i measured the voltage in the A4 pin and nothing happens, i have no signal even over 4k or 5k rpms (i have set the vtec at 4k).

Doing some research i found a post with the same problem: http://www.hondata.net/forum/viewtopic. ... 03dbb7e292. My car presesents the same diagnostic, but i can't find another ecu with a s300. I'm living in Venezuela and this model was not commercialized here, this car was imported directly from the US, so i have no parts available here. Can i send you the ecu to repair it or replace it? i realy need to solve this issue.

Thanks

i cant exactly remember but is the P28 expecting a vtec oil pressure circuit input & your D16y8 doesnt have the oil pressure switch?

its hard to know anything when u dont post your cal & maybe a datalog,but just try disabling the vtec oil pressure under the vtec parameters tab if u havent already.

also just check your meeting the minimum requirements on the vtec tab as well,like speed ,throttle,temp,oil level,etc
if your just reving the motor while stationary & expecting vtec output,then u will find u'll have to meet the minimum speed requirement u have set before vtec will activate,not sure whether u can set it to zeroMPH or not,never tried that lol.

thanx fly, i'll try disabling the oil pressure in the vtec parameters.

The parameters on the vtec tab are:

• 9 mph minimum speed
• tps over 50%
• 4 psi intake pressure
• 3900 rpm

Those are what i remember, when I measured the voltage output it were present all those parameters, except for the vtec pressure switch, let me check all the things and post again

that 4psi u have set,just make sure where your vac/pressure reference is taken from in the options/settings window,ie is it absolute or atmospheric,in other words u might not be seeing vtec until u see 4psi boost from the charger.

im not sure whether disabling the vtec boundary window with same vtec switching rpm values in upper & lower boundary will entirely rule out the intake pressure min requirements,but could be something worth checking.

ok, finally here are the calibration that im running and the datalogin from few days ago, the problem is the same VTS code 21, im thinking that i could use the non vtec engines option to send the signal to another pin...

ill be waiting for your answer!!

Have you tried your ECU in a known good vehicle? What does the ECU say on the outside sticker?

No, all the civics made and sold in Venezuela are non-vtec (most are equiped with d16y7 and some with d16y9), only that ones imported could have vtec, and it depends on the model. Right now i don't know anybody that have a vtec civic, because of this i made all the messurements to be shure that all the vtec components are ok.

I'm pretty shure that it's the ecu, i don't know if this problem it came with the ecu or happened when the ecu was socketed. I think that i could use another pin for the vtec, i don't know if this works having this problem, what do you say?

37820-P28-A51761-603854
S300 SERIAL: 3659

Try the S300 in a different ECU, or you can try the alternate VTEC output with a relay.

http://www.hondata.com/techvtecrelaydiagram.html