ECU Codes

[harwood39]

Ok. I ran the codes on my civic, and i got a 3 (MAP Sensor) and a 22 (VTEC Pressure Valve) My question is how easy is it to replace these, and could they just be throwing codes due to my VAFC?

Thanks for the help in advance

[Joel]

probably the vafc, since thats what it hacks into. if its like an safcII, take apart the unit, and you can unplug the cords coming out of it from the board. then reset your ecu and see if the codes disappear.

[harwood39]

Actually i just thaught more about it, and if it was caused by the VAFC, it would have been running like shit since i installed it, and the check engine light would always have been on, not just start running like shit in the last week and stuff.

But holy piss MAP sensors are spendy, $170 at Autozone, and $217 at advanced auto parts. I think i am goin to just get one out of the junk yard.

[Joel]

trust me, check out the vafc first! cheaper than spending 200 bucks on a map sensor. maybe your vafc went bad! that could cause the codes, and wouldn't have set off codes until it broke!

[harwood39]

in order for me to check the vafc, i have to redo all the wiring for the ECU, the VAFC taps into the ECU wiring harness. I cant just unplug it, cause than it wouldnt read the map sensor at all.

[harwood39]

Oh ya, and it will run fine for about ten to 30 min(depending on day and temp) and than start to miss a little, than just shut down and start back up but with a really bad idle and wont have any throttle response.

[Joel]

how would it not read the map sensor? all you did was tap into wires from your harness. if you pulled the cord, it would be like nothing was ever plugged in.

[harwood39]

nope, the VAFC actually is imbetween the ECU and harness for those sensors not just tapped into the wires, other wise it would be pointless and not do anything. The sensor sends the signal to the VAFC, than the VAFC sends it to the ECU.

[Joel]

i give up. VTEC TUNING IS OUTTA MY LEAGUE!

[pin]

All piggyback tuners have to intercept the ECU's signals. That's why they're not as flexible as a standalone controller; they're still just fooling the computer. Check to make sure your connections are still solid. Also, there should be some tests you can perform on the MAP sensor and VTEC pressure valve. A vacuum pump, ohm meter, and the resistance specifications should be all you need to test a MAP sensor.

[integra_gsr98]

You wired the vafc wrong. Chances are your MAP and Vtec wires are backwards. Swap those around and try again.

[harwood39]

nope map and vtec were correct. I removed the VAFC and put the wiring back together. I reset the ECU. No more code 3(MAP Sensor) so thats good, but i still got a code 22(VTEC Pressure Valve). So i need a new pressure valve. Also the VAFC worked perfect for 6 months and now it went weird so that another reason why i know it was wired correctly. Plus i went through the wiring like 10 times when i installed it.

[Joel]

told you your ecu wasn't bad. you owe me 200 bucks!

[harwood39]

i knew it wasnt bad once i ran codes.