Wiring diagram of driver side EVAP pressure sensor?

Tiny
LOUIS W NAGY
  • MEMBER
  • 2002 CHEVROLET CORVETTE
  • 101,234 MILES
I know what problem is; the pressure sensor on driver side fuel tank is bad. Book does not even show it, but when I did evap test with scanner it’s shows it. Took a while to diagnosis this problem, but now driver side fuel tank cannot be removed without doing damage. What I need is a wiring diagram of driver side pressure sensor to ECM, so I can relocate sensor to different location. I could not find one with my resources. Factory manual did not even show to have one. I had to dig just to find pictures of it. If you could help that would be great.
Saturday, September 26th, 2020 AT 9:13 AM

9 Replies

Tiny
STEVE W.
  • MECHANIC
  • 14,327 POSTS
It's a 3 wire sensor, 5 volts on the grey with black, sensor ground to the grey wire and the signal comes out on the dark green wire. It is a push in sensor so if you can even see or feel it it just pulls out and pushes in. Some have a small tab that you can bend out to release them. Be careful where you locate it, it need to see the same conditions as the tank with no blockages, otherwise when the system applies vacuum it could either cause an EVAP code or worse it could suck the tank in on itself from the vacuum.
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Saturday, September 26th, 2020 AT 10:25 AM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
Thanks Steve, I’m going to send you my VIN and if you could please send me a pin out of my ECM that shows both left and right tank sensors. Also, I was wondering what it’s like working for your company. How good do they pay? I just got let go after 15 years. Thanks

Louis Nagy
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Sunday, September 27th, 2020 AT 11:07 AM
Tiny
STEVE W.
  • MECHANIC
  • 14,327 POSTS
There is only the single sensor which works to test the system. The sensor is in the left tank and is the only one required at that time as the car treats the dual tanks as a single tank. The three wires from it are in the harness at the tank. That is why relocation isn't going to be easy as the programming for the tests know how long it should take to pull vacuum and release it on that system, so anything else is likely to set a code.
As for the work, I like it and don't have an issue with the employers or other employees. The pay depends on effort. If you want to know more just follow the link.
https://www.2carpros.com/articles/we-are-hiring
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Sunday, September 27th, 2020 AT 11:48 AM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
Okay, thanks for input. Apparently at the time of manufacture some vehicles I had one sensor and some vehicles had to apparently at the time of manufacture some vehicles I had one sensor and some vehicles had 2, the date of manufacture 01/02 vin# 1g1yy32g525120205. I will send you a screenshot off my scanner and you can see them. I did not record the evap test but I have a pic I can send you, I did test 3 times and the driver side sensor never moved, at the end of last test I manually purged system for long period and when I released the system back to sea level the driver side moved like 0.1 the passenger side functioned as it should. I will send you a screen shot of it the bottom sensor is driver side. I’m contemplating piggybacking off the passenger side sensor and see if that would work what. Do you think? I just need pin out PCM regardless my other choice is tuner shop down the street will fix for $150.00, but just got laid off so want to try everything first. Thanks for all in put.
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Sunday, September 27th, 2020 AT 5:03 PM
Tiny
STEVE W.
  • MECHANIC
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Yeah, that would likely be a bad sensor, or the wiring is corroded. If it has two sensors then they wouldn't be linked and you can't piggyback one to the other without causing a fault. However, I just looked at GM TIS for that car and it only shows a single sensor, unless someone added something to it or it's a custom built car, there is no other wiring diagram for it.
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Sunday, September 27th, 2020 AT 5:55 PM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
Here is shot off scanner.
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Sunday, September 27th, 2020 AT 7:37 PM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
Well, could you send me pin out for ECM for that VIN I sent you? Just makes no sense why my scanner shows it and there is no way to drop that fuel tank down. I even put a come along on frame to give it more room to drop down and it would not budge. Now when I was looking I came across a picture of a driver side fuel with a sensor mounted just above fuel filler neck. But it was an 2003. This is just how my luck runs with this car. I got at least $10,000.00 in engine and transaxle. I’ve spent a lot of money on ABS modules, door modules, etc. If you could just send me the pin out, let’s just call it done deal. Thanks anyway. Have a good one.
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Sunday, September 27th, 2020 AT 8:09 PM
Tiny
STEVE W.
  • MECHANIC
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No image.

Ran the VIN through GM and it shows only a single sensor. The sensor ground is shared with the fuel level sensors in both tanks. If the fuel gauges both work the sensor ground is likely good. That leaves the 5 volt and signal return. The 5 volt reference is only for the sensor it is on pin 46 on the PCM a grey wire with black stripe. The signal return is the dark green wire on pin 64 in connector 2 at the PCM.
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Sunday, September 27th, 2020 AT 8:11 PM
Tiny
STEVE W.
  • MECHANIC
  • 14,327 POSTS
Hmm, the images didn't attach either.
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Monday, September 28th, 2020 AT 3:55 AM

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