OregonHHR

How does our car determine the alcohol content in our fuel? I recently ran into a problem when the computer determined I had 67% alcohol content in my fuel when it was really 10%.

donbrew

The O2 sensors I have been told. I used to think it was a module in the fuel pump.

I just typed "alcohol" into the search and the very first link was the one in which I was corrected.

Blue_SS

I know there was a change made, but can't seem to find out when it was implemented. I DO know that the sensors in the tank were a warranty issue due to some type of electrical issue. They were a part of the pump/sender module. I will look some more, and see what I can find. Here's a thread that has some info on the topic, too.

https://www.chevyhhr.net/forums/gene...ex-fuel-18111/



I found this from here:
http://www.gmpowertrain.com/Powertra...s/10_LAF_n.doc


E85 Flexible-Fuel Capability (LE9)
GM has led the industry in introducing flex-fuel capability to its cars and trucks, and the new flex-fuel 2.2L I-4 VVT ( LE8 ) extends availability to an even broader range of customers. E85 is a clean-burning alternative fuel made in the United States from corn and other crops, composed of 85 percent ethanol alcohol and 15 percent gasoline. The 2.2L's flex-fuel technology is both sophisticated and durable.

Flex fuel engines require special valves and valve seats to withstand the wear and corrosive effects of ethanol. The nitrided Silcrome 1 intake valves and 21-43 exhaust valves used in the 2.2L I-4 are up to the challenge. Compared to conventional iron-alloy valve material, nitrided Silcrome 1 includes tungsten, vanadium, manganese, silicone and higher chromium content. It is harder, and it improves durability, even under the rigors of ethanol operation. The 21-43 exhaust valves work equally well. Valve seat inserts have been upgraded to premium materials with a high percent of tool steel and solid lubricants resulting in excellent durability whether E85 or gasoline is run in the engine.

Hardware changes for flex-fuel operation are limited to the injectors. Because ethanol has fewer BTUs (less energy) than the same volume of gasoline, more fuel is required to produce the same horsepower at wide-open throttle. Flex fuel engines use unique stainless injectors with a greater cone angle and higher maximum fuel-flow rate. The fuel rail matches the injectors, but it's manufactured of the same stainless steel used for all 2.2L I-4 fuel rails.

The flex-fuel 2.2L doesn't require a special fuel sensor. The first flex-fuel engines used a light-reactive sensor to measure fuel composition from 100 percent gasoline to 85 percent ethanol. The 2.2L has a virtual sensor-software programmed in the E37 ECM with no separate physical sensor whatsoever. Based on readings from the oxygen (O2) sensors, fuel level sensor and vehicle speed sensors, the ECM adjusts the length of time the fuel injectors open for the type of fuel used. Within a few miles after filling up, the E37 controller determines what fuel is powering the 2.2L I-4 and manages the engine accordingly.



Which backs up the above thread , but doesn't specify a start date. It pertains to the 2010 Malibu, so I think making the assumption that it applies to an HHR with the LE9 is pretty safe. It describes how it works, but doesn't say it's new for 2010 or anything like that.

chefhhr

I've had this same problem. It caused my car to become very hard to start up in the mornings. Once I got it diagnosed they were able to go in and fix the issue. Luckily it was still under warranty at the time.

black Tara

what year is your car? does it say you can run flex fuel?
If not and you used flex fuel that's your problem. If your fuel is almost empty fill back up with high grade unleaded fuel and that should fix your problem. if it's still full of flex fuel, you will have to drain your tank and refill with unleaded fuel

whopper

If you do a quick check via his profile you will see he has a 2010 2.4L - and if you reread his first post, you will see he did not use flex fuel (ie: he used 10%).

2005HHRauto

This is the correct info for 2010 HHR:
http://www.gmpowertrain.com/Powertra...s/10_LE8_n.doc

2005HHRauto

Let's keep it really simple.
With a flex fuel, HHR, the computer is programmed at the factory, with E0-E10, as the 1st fuel, in the tank, from the factory, which results in fuel trims
of, lets say, ZERO

When you add, greater than E0-E10 fuel, MUST BE 3 GALLONS, OR MORE, the computer knows, via the O2 sensor, what was put in the tank, & how much, was put in the tank, the air-fuel-ratio, will go LEAN, if greater than, E0-E10, was put in the tank.
Whatever that percentage is, translates, into a know percentage, of flex fuel, via, the computers, look-up tables. It's really a simple, fool proof way, of knowing whats in the tank. And each 3 gallons, or more, put in the tank, after that 1st fill-up, whatever it is, E0-E85, will cause the air-fuel-ratio, to go leaner, or richer, or stay the same, & the computer KNOWS, your flex-fuel ratio.

BUT & this is a big BUT , if you put in less than 3 gallons, when going to the gas station, you are ****ed, you are screwed, big time, as the computer only recalculates Ethanol content, when 3 gallons or more, is added at fill-up...

GM is counting on people, putting in more than 3 gallons, when they fill-up, at the pump. That's what is causing alot of problems, because people do go, to fill-up, with less than 3 gallons, being added.
One example is when you borrow someones car, & you want to return it full, as your a nice guy, & you can tell the cars owner, that you returned the car full. Or, before returning a rental car, you top it off at the last gas station, before turning it in. Or my favorite, your kid knows that you filled the car up, & he sneaks out at night, returning the car, making sure that it is full, of fuel...

Also, if you ever have to replace the ECM, your car needs to have E0-E10 in it, BEFORE YOU 1ST START IT UP, or your screwed...

From my 2009 service manual:
Refueling events, MUST be 11 liters, (3 gallons), or more...
So really, only 3 things can go wrong, for proper flex fuel calculation, for a flex fuel HHR:
1. bad ECM
2. bad O2 sensor
3. putting in less than 3 gallons of fuel, in the tank, as it won't be calculated,
as a refueling event.

!!!! OH ****, I JUST FOUND A BIG ISSUE !!!!
Numerous short trips, right after a refueling event,can result in incorrect,
flex fuel calculation, due to the inability of the system, to adjust for fuel composition, by not attaining Closed Loop operation.
This means that after you tank-up, you go across the street, to grap a bite to eat, than you go a block away, to the bank, than another block away, to work.
Your ****ed, this system really sucks...

2005HHRauto

A guess GM got smart, & went back to using a sensor again.
This is info, from new GM truck literature:

Flexible Fuel Sensor
The flexible fuel sensor measures the ethanol-gasoline ratio of the fuel being used in a flexible fuel (E85 capa¬ble) engine. Flexible fuel vehicles can be operated with a blend of ethanol and gasoline, up to 85 percent ethanol.
The flexible fuel sensor uses quick-connect style fuel connections, an incoming fuel connection, and an outgoing fuel connection. All fuel passes through the flexible fuel sensor before continuing on to the fuel rail.
The flexible fuel sensor measures two different fuel related parameters, and sends an electrical signal to the Engine Control Module (ECM) to indicate ethanol percentage and fuel temperature. Since the flexible fuel sensor measures the actual percent¬age of ethanol in the fuel, it is no longer necessary to wait for an empty fuel tank in order to refill with E85

firemangeorge

Nice info above but what year(s) and model(s) does it pertain to ?