If you paid $50 for a part that goes for $100 everywhere else, do you really need to ask?

https://www.gmpartsdirect.com/oem-parts/gm-sensor-13577429
it cost 47 usd but shipping to europe was too expensive on this website.

you don't buy important sensors on ebay. you never buy anything important on ebay. ever. if you do, just know that it's a stupidly risky thing to do and be prepared to deal with the consequences. 8 out of 10 things (injectors, fuel pump, sensors, etc) are usualy fake/knockoff

Seriously. It's one of the very few sensors that actually dictate how much fuel is delivered to the engine. It's like buying a knockoff MAP sensor, or a knockoff fuel pump. If it fails, it takes your engine with it. Such an awful place to try to save $50.

hate to say it, but uhh they are right. Dont be me. My sensor is defective I'm pretty sure.. Reads 1% max eth. Pretty sure my car kept going into fallback fuel multiplier because of that and made my car superrrr rich.

I'm mad.

edit: redid grounds and now reads nothing. Was previously grounded to intake manifold. Now connected to sensor ground guess ill do without a flex for now

edit2: Just wanted to give more info on my defective sensor from ebay - The difference between that an the acdelco variant, same part number - was that the ACdelco had lighter lettering (white) and has made in mexico stamped on it. The ebay one did not.

Hey. Got stuck here!

I just picked up the GM sensor (13577379) for my 2003 with the MS3P PNP. I can't figure out where to connect the signal wire to the ECU. The manual states that it should connect with "digital switched in 1 on the options connector" but when you look at the pin-out diagram for the options connector that input isn't there (see link). Thanks for your help!


Options Connector

For some reason, DIY brings the clutch in on that input. You have to move your clutch to a different input in order to use flex fuel. I tried on mine but couldn't get launch control to work on mine after doing so. I would be willing to try again, but the car is in another state and I won't have it for quite some time.

The manual makes it sound like you have to choose between launch control and flex fuel. I'm not sure why that would be the case with so many inputs on the MS3. I don't really care about launch control for my application, I just need to figure out where to move the clutch.

Interesting - on MS3Pro for 94/95, there is a digital in that's pretty much earmarked for Flex Fuel - not so for 01-05.

Any reason you can't use digital in 2?

The only two options under FF in TS are "dig. switch 1" and "dig. frequency 1".

Since I'm not interested in launch control (this is a track car) I just unplugged the front clutch switch to free up that input.

Still not seeing a signal in TS. Re-verified 12V, ground, and signal wire continuity. Tomorrow I will attempt to measure the frequency coming over signal wire with a MM.

So I'm getting weird readings from the FF sensor. The frequency measurement output comes intermittently, about every 25-30 seconds (counting in my head). In between it drops to zero. Should the signal be constant or should it pulse like that?

This is my second FF sensor (13577379) and I've checked all wiring (ground, 12v, and signal wire continuity).

I just discovered some latent voltage over the ground I was trying to use, about 8v. I tested it for impedance but didn't think to test for voltage. I moved the FF sensor to a better ground but I'm not seeing any signal.

I'm worried I fried my sensor. Is the test pictured in the original post still accurate with what we know about sensor 13577379?

Also, just double checking I have the harness wired correctly:

• Vcc to 12v
• Gnd to ground
• Out to Options connector N

12v from MS3 options connector
 

Does anyone know if it’s safe to use 12v ignition out from MS3 Pro (DIY auto tune) on the options connector to power the flex fuel sensor ? The 12V max current is .5amp and hopefully the continental sensor draws less. Maybe do more googling on the continental specs