Utec installed.. Question (help)
Update for you guys, I removed my Utec and the code is gone. It is definitely the Utec affecting this for people in high altitudes. Btw I have had my Utec out for over a month now and no recurrence.
Originally Posted by jeremybudd
So is there anyway to know for sure if the purge valve system is acutally working when the light is on?
I have emailed back and forth a few times with Jermaine this is what I have found so far.
P1444 code present with Utec installed I would test the voltage of the purge valve solenoid harness by the plenum. It would read 11.45 volts when I would test the positive and ground on the harness. I would then test the positive and another ground source(plenum or solenoid bracket) and would get 11.55 volts. Battery voltage at this time was ~12.3V
OEM computer mintues later the voltage would read 11.55 when I would test the positive and ground on the harness. 11.65 when I would read the positive on the harness and the other ground source.
Then I was convinced that the Utec was not giving the correct voltage to the solenoid. I emailed Jermaine and he asked me to test the resistance in OHM's of the solenoid alone, with the Utec and with the OEM computer. I tested the resistance with just the solenoid out of the car and it was at .022 OHM's. I am not sure how to test the resistance with the harness hooked to the solenoid to verify the OHM's with the OEM and Utech hooked up. If you know how please let me know.
Then I put the Utec back in and the code came back after 3 starts or so. I tested the voltage again this time it was at 12.35V and 12.45V(other ground). I check battery voltage and it was at the 12.35V.
The manual I have says the solenoid should be receiving battery voltage.
I have the OEM computer back in now and will go for a week and see if the code comes back. I am not sure what else to try since the Utec was giving the solenoid battery voltage this time even after the code was thrown.
I have emailed back and forth a few times with Jermaine this is what I have found so far.
P1444 code present with Utec installed I would test the voltage of the purge valve solenoid harness by the plenum. It would read 11.45 volts when I would test the positive and ground on the harness. I would then test the positive and another ground source(plenum or solenoid bracket) and would get 11.55 volts. Battery voltage at this time was ~12.3V
OEM computer mintues later the voltage would read 11.55 when I would test the positive and ground on the harness. 11.65 when I would read the positive on the harness and the other ground source.
Then I was convinced that the Utec was not giving the correct voltage to the solenoid. I emailed Jermaine and he asked me to test the resistance in OHM's of the solenoid alone, with the Utec and with the OEM computer. I tested the resistance with just the solenoid out of the car and it was at .022 OHM's. I am not sure how to test the resistance with the harness hooked to the solenoid to verify the OHM's with the OEM and Utech hooked up. If you know how please let me know.
Then I put the Utec back in and the code came back after 3 starts or so. I tested the voltage again this time it was at 12.35V and 12.45V(other ground). I check battery voltage and it was at the 12.35V.
The manual I have says the solenoid should be receiving battery voltage.
I have the OEM computer back in now and will go for a week and see if the code comes back. I am not sure what else to try since the Utec was giving the solenoid battery voltage this time even after the code was thrown.
Then, you will need to compare the raw output of the ECU vs. the output of the UTEC. I would guess that this would be a pass through signal, but apparently it's not.
Also, you can't test the resistance of the solenoid under different cirumstances- it has a constant, non changing resistence of 0.022 ohms (most likely 0.022Kohms). You must disconnect the solenoid completely to measure this value.
The service manual states that this code is caused when the solenoid is open when it should be closed.
Nope, I still get P1444. And when I went to Hastings, NE (lower altitude), the P1444 went away, and did not come back until I got back to CO. I offered multiple times to run tests with TurboXS, but they pretty much iognored my emails.
Another reason to move back to Texas!!! LOL
I just found out I am transferring to Monterey, CA next summer. Right next to Laguna Seca. % big tracks within 300 miles: Willow Springs, Button Willow, Laguna Seca, Infineon, & Thunder Hill!
Originally Posted by Dave 90TT
I just found out I am transferring to Monterey, CA next summer. Right next to Laguna Seca. % big tracks within 300 miles: Willow Springs, Button Willow, Laguna Seca, Infineon, & Thunder Hill!
G35... AutoPC... JWT TT kit... StopTech BBK... Running NASA w/ wife aproval... & now this!!! Thanks for adding yet ANOTHER reason for me to be jealous! 
Registered User
Joined: Jul 2007
Posts: 260
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From: Gilbertsville, PA
fix yet? anyone figure out which pins these are on the ECU and do their own pass through wiring to make it go around the utec instead of through it to possibly see if this would repair it? If this solves it, than utec could easily make a "patch harness" for the z's with this problem.
Anyone see where I am going or possibly be able to try this?
Anyone see where I am going or possibly be able to try this?
What kind of boost levels are you running? I've tried to set my at 12psi in closed loop and it overshoots like crazy. Adjusting the "gain" has absolutely no effect on the operation of the boost controller.
I've heard that closed loop works fine at lower boost levels when you don't have to adjust the gain, but at higher boot levels there is no tunability.
Open loop works great, but here in Ohio I need a bit more control then open loop can provide (temp changes).
I've heard that closed loop works fine at lower boost levels when you don't have to adjust the gain, but at higher boot levels there is no tunability.
Open loop works great, but here in Ohio I need a bit more control then open loop can provide (temp changes).
Registered User
Joined: Jul 2007
Posts: 260
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From: Gilbertsville, PA
if I could get 2 cheap "patch cables" to make a fix out of, and figure out which wire is for the valve, I would. All one needs for a very primative fix would be two straight through patch cables, cut the lead on the end near the utec, run about 6 to 12 inches of wire off of it, cut the lead on the other end near where it would plug into the utec on the other cable, and attach back.
Unless this pin that controls that guage also controls any other systems that I am unaware of? Or if maybe utec uses this singal somehow to data log anything? I am unsure. I do not own one yet, but I remember having to do something like this on my DSM when i was non turbo because I was using a turbo model's engine tuning software and device. I was able to get it to successfully integrate, although with all my soldering skills, the car always smelt a bit after, and the brown burnt metal spots behind the radio were easily hidden haha.
Unless this pin that controls that guage also controls any other systems that I am unaware of? Or if maybe utec uses this singal somehow to data log anything? I am unsure. I do not own one yet, but I remember having to do something like this on my DSM when i was non turbo because I was using a turbo model's engine tuning software and device. I was able to get it to successfully integrate, although with all my soldering skills, the car always smelt a bit after, and the brown burnt metal spots behind the radio were easily hidden haha.
You wouldn't need a full patch cable - I believe it is just one wire. You would have to locate the correct pin on the UTEC harness and then find the right wire on the stock ECU connector. Connect them so that they don't go through the ECU and it will be bypassed.