Fuel tank pressure sensor code with no sensor on the fuel pump

Pacopico

Member
Mar 5, 2011
10
0
Wa
To start I’ve PM’d Will Tillery but I am posting this while I wait...Just in case.

I have a 2003 DII with SAI, bought a matched ECM/BCU/Fob from Will for SAI delete.

Prior to the install I had no CEL, only pending code was SAI Right bank...hence why I wanted to delete...also I needed a fob.

I installed the BCM/ECU, started up and immediately had O2 and fuel tank pressure codes.

Replaced all four O2’s, cured that problem fuel tank pressure code persists.

The code description says “shorted high”, and looking in the manual it is a 3-wire pressure transducer so shorted high =+4.5V or higher is being seen on the sensor return pin.

So I pulled up the carpet and looked at the fuel pump - no pressure sensor.

I also searched and found this old thread: https://discoweb.org/index.php?threads/another-sai-thread.82914/#post-953770

Looks like I have an elusive 49-state emissions w/SAI truck.

Has anyone ever solved this?

The only diagnostic tool I have is the AB “iLAND” app/dongle.

Cheers!
 

rovercanus

Well-known member
Apr 24, 2004
9,364
89
Good question. I have the same thing and as far as I know we will need to change the fuel pump to one with a pressure sensor.
Since you have had the carpet up, is the wiring there for the pressure sensor? If not, we'll have to look into tricking the ecu to think there is a sensor there.
At this point I haven't bothered looking.
 

Pacopico

Member
Mar 5, 2011
10
0
Wa
Sadly no wiring at the pump. Also no wiring at the ECM. The pin for sensor return is empty.

Makes me wonder why the code says shorted high...should be shorted low/open
 

rovercanus

Well-known member
Apr 24, 2004
9,364
89
I'll have to look through RAVE and check the theory of operation for the sensor. I took a quick look when I did my truck but didn't pursue it much after that.
 

discostew

Well-known member
Sep 14, 2010
5,868
323
Northern Illinois
We used to look at the carbon canister to tell if it was advanced Evaps. If it's got the round can looking one it's not advanced Evaps. The rectangular one would have the sensor back there.
It's possible it has the wrong ECM I suppose. But then I would think just the PROM would take care of that.
 
Last edited: