So I have a OBD2 B18C engine that does not have the VTEC pressure switch and im running a chipped P06 and the CEL came on. Code was 22 so I did my research and did the "VTEC pressure switch bypass". CEL went out and I thought everything was fine. I take it for a run and VTEC kicks in at around 5700 then at about 7000 the CEL comes back on and drops out of VTEC and codes are 21 and 22, solenoid and pressure switch... Cant figure this out, someone please help!

 

Double check to make sure you wired the bypass correctly.
http://www.phearable.net/tech/wiring/vtpsbypass.gif

Are you using an appropriate ECU conversion harness? Im guessing your car is a '00 and you are putting the OBD1 Civic DX ECU in it.....

 

I wired it by soldering the power wire of the pressure switch to the VTEC solenoid signal wire in the engine bay.
Does the other pressure switch wire need to be grounded? I tried that as well and the same problem is still happening. Any other suggestions?

 

The pressure switch to the vtec solenoid signal wire? That makes no sense at all to me. So the ECU grounds the vtec solenoid to activate it and then that grounds the pressure switch? No wonder you're having trouble.....

 

Do it on the ECU harness. Make a jumper wire from POINT A4 to POINT D6 on the ecu harness like the link shows. If that doesnt work then unplug solenoid and pressure switch and run a wire from solenoid and tap into the wire that connects A4-D6.

 

I did the jumper from A4 to D6 and VTEC kicks in but at 7000 the CEL comes on and drops out of VTEC and throws a Code 21???

 

Check you oil level. If it is low the solenoid will not be able to maintain pressure at higher RPMS.

 

Oil level is fine. Should there be a ground anywhere or should one be removed that im not aware of? Ive read many forums on this issue and they all say the same basic thing but im still having an issue!

I have the wire coming from the ECU to the VTEC solenoid, I have A4 and D6 spliced together and a confirmed connection. VTEC kicks in at 5700 then drops out at 7000 CEL comes on with code 21.

 

BUMP!

Still needing help! Ive tried many different ways of wiring it and nothing is fixing the problem. Why is it dropping out of VTEC at 7000 and throwing code 21??? I am gonna try a D series VTEC pressure switch and solenoid unit on it and see if it works on the weekend but somehow i have my doubts it the bypass wont even work. I hope its not something wrong the the computer (Chipped P06 converted to a P28)

 

Update::: I was assuming my oil level was ok, but I just checked it when the engine was cool and there's just enough oil in there to show on the tip of the dipstick, plus the coolant is low. So I'm gonna top everything up and do an oil change and that should fix my problem! Makes sense since vtec engages but then drops out at higher rpms and only throws a code 21.

 

Topped up the oil and the coolant, still having the same problem! Any more ideas ????