I just got the s300 and my IAT is reading 284 without ever starting the car. I assumed it was a dead sensor so I swapped it out with another and still reading 284. Now I'm assuming that their has the be either a short or open somewhere between the sensor and the ecu causing a false reading. Just wanted to make sure their wasnt something that I need to change somewhere in the settings to remedy this problem. Sorry for the newb questions but I just needed a little clarification before I start ripping apart my harness.

in case it matters:
d16z6 vitara motor
bisi 3.6 cam/springs
stock injectors and pump for now
s300/p28 in a obb1 converted crx.

 

Make sure you have it plugged into the right connector on the harness...very common to plug the EVAP to the IAT sensor and vice versa

 

Only time I have seen such an issue is when the customer swapped the evap purge and iat sensor plugs as chris mentioned. The IAT sensor will become damaged. The tip of the sensor will usually melt...

Check the sensor using an ohm meter to diagnose if the sensor is providing the false reading. You should see around 1-1.5 ohms between the iat sensor terminals.

 

I was hoping you guys would chime in! I really appreciate your input. IIRC, the crx's evap plug is located with the map sensor wiring on the firewall and is a completely different size plug. The only thing close and similar to the IAT is the IACV which I swapped just to see and not only did it not help, but the car died as soon as the IACV was unplugged.

 

Could just be your sensor is dead...check the resistance across the two pins of the IAT

take it out of the manifold and inspect it as well

 

IAT sensor is likely burned up and its plug was accidentally swapped with another sensor. I received the exact same reading - 284 deg - when someone had theirs swapped with evap.

 

mined burned up and was reading -33 degree. I accidentally had mine plugged in wrong as mention above

 

We have a quick step by step test of the IAT on our site to help you out:

Intake Air Temp Sensor Diagnostics - HA Motorsports

This will tell you if the IAT is bad. As mentioned above, most likely it was switched with the IACV at some time or another which fries the end of the IAT..

 

Very useful info there!!! I finaly got it off where i could get my meter to it and sure enough, its dead. 0 ohms. Its burnt into apparently.

Another concern now.... I wanted to play with the s300 a little, just kinda learning my way around, so I plugged it into my daily driver. Its a gs-r swapped ek coupe thats been running a chipped p72 for going on 10yrs now with zero issues. I hooked up the new ecu with the hondata, selected the oem p72 map and drove around for a bit. No vtec. It popped up a error code for the vtec spool. I disabled it just to see. No codes now but still no vtec. Any clues? It works with my old chipped ecu but not with the s300.

 

What ECU are you using with the S300?

 

Funny you should ask... It was sold to me as a p28. Its in a p28 casing. I pulled the cover off to look at the board and its labeled p06 across the top of the plug where it connects to the car's harness. I'm assuming now the the vtec output isnt on the same pin on the p06 as the p28.

 

If the P06 board hasn't been modified for VTEC, then that is your problem. Can you post a pic up of the ECU with the lid off?

 

I'll get pics tomorrow. I'm fairly sure its been converted though. It supposedly came out of a boosted b16 hatch.

 

Sometimes tomorrow comes a month later...



Hopefully you can see what you need.

 

Your p06 ecu has not been converted to Vtec.

 

well thats not what I wanted to hear... I have a another chipped p06 that has been converted. Is it as simple as removing the s300 from this board and placing it on the vtec board? Or I guess I'd actually be swapping the vtec p06 board into the modified casing then installing the s300 board back on to it... Is it that simple?

 

No it's not the s300 uses male pins, not a socket. So "swapping" the s300 to a socketed ecu isn't going to work.

Simply order a DIY vtec conversion kit and convert the ecu to vtec or use an alternate vtec output and a relay to control vtec (read the smanager help file).

You could also mail the ecu to a vendor or have a local hondata dealer add vtec components to the ecu.

 

Simply send it to this dude ^^ or Chris at Xenocron.com

 

Finally back to working on this thing. I have replaced the bad sensor with a different sensor that measures ~1.5-2 ohm. I've checked and have voltage (5v) at the bottom pin, checking to both chassis ground and to the upper pin. Its now showing 123 degree's but I have a error code for the IAT as soon as I turn the key foward where I didnt before. This makes no sense to me... Could this be something with the ecu? or should the sensor be reading closer to 4ohm?

 

bump for answers please.

 

I would suggest checking continuity from the plug you are using for your IAT sensor back to the ECU, and make sure you are not having any issues with the wiring there.

The default reading will be 123, when it errors out or is not plugged in.