Have a 2007 ION with a faulty fuel level sensor and a CEL on. Was wondering if this sensor could be bypassed to get CEL off for the car to pass New York State safety inspection. My thought was installing a resistor in circuit instead of the FLS. I do not believe I can drop the fuel tank without causing other issues due to rust of the undercarriage.

 

I would determine which wire carries the sender information to the gauge (likely via the BCM) and replace that end to end to ensure that the issue is not the wire itself.

If that doesn't work, then you will need to measure the voltage drop across the sensor supply wire to ground to determine what value of resistance you would need to plug in to make it read say half full. It needs to be between 3/4 and 1/4 or the evap emissions tests will not run and the vehicle will never have all of its status monitors in the ready state and you will fail inspection.

What codes do you have? Please post as PXXXX where the X's are numbers. Just the codes, not the explanations.

Also, how do you know that the float in the tank is not the issue, meaning it may be stuck, thus reading a constant fuel level?

What fuel level is displayed on the gauge?

You may have the option of swapping instrument clusters, but then you lose the mileage on the vehicle which is stored in the BCM. Additionally, the cluster must be married to the BCM in order to document or shall I say accumulate miles on the odometer. I believe that must be done by a dealer.

 

The code I can recall from when the car was last on the road was P0463. The fuel gauge for the most part reads empty ( when I had the car on ramps today the fuel gauge went to 1/2 when I moved the car off the ramps but after a short period it went to empty.

 

Does it have a half full tank? If the wire grounds GM gauges read empty, it may just be wiring grounding out. If the wire is open fuel gauges read way past full.

 

Unsure how much fuel is in the tank

 

Just received a new code reader and pulled these codes today. P1174, p0463, p0446, p0138, p0113 and p0102. Some of these codes are both stored and pending. Thoughts on a systematic approach to address these? Thanks

 

P0102 MAF circuit low
P0113 Intake Air Temperature Circuit High InputP0138 O2 Sensor Circuit High Voltage (Bank 1, Sensor 2).
P0446 EVAP vent control circuit malfunction.
P0463 Fuel Level Sensor “A” Circuit HighP1174 Fuel Trim Cylinder Balance Bank 1
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Step 1: Clear the codes and drive about 60 miles. The SES CEL will turn on before that, but some of the emissions codes often take longer to set.
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My GUESS is that the wrong IAT info and MAF info are going to the PCM, causing the wrong air to fuel mix. The high voltage on the downstream O2 may be a result of the air fuel mix being messed up.

The vent control circuit may be a bad vent control solenoid.

The fuel level sensor code seems to indicate the issue is with the fuel sensor in the tank, but this can always be related to wiring as well.

Let us know which codes come back.

 

Thanks for the response, will attempt to get this done this weekend.

 

Ok was able to drive the car last night for 66 miles. Only codes read are po463 both stored and pending. Not sure in NY if they can inspect the vehicle with a CEL on as the only monitor not green is the EVAP. Will research that. John

 

The evap tests will not run without the fuel level sensor. This is because one of the criteria to be met before the evap tests will begin is that the car must have been ice cold engine wise for about 8 hours but more importantly the gas level needs to start and stay between 3/4 full and 1/4 full. Otherwise the tests will not begin. Since you have apparently no fuel indication going to the BCM or PCM, it seems the fuel level it is reading must not be between 3/4 and 1/4.

I know Andy said something about how it will likely read based on what the problem is. I'm thinking if you can fool the PCM input by supplying it a voltage that corresponds to a half tank of gas, you may be able to get the evap tests to run and clear the code at the same time because the fuel sensor reading will be valid as far as the PCM is concerned.

If you have any p codes and a CEL you will fail emissions in pretty much any state as far as I know, so this must be dealt with.

Not sure when your emissions sticker expires, but in most states you have the option of intentionally failing your vehicle. This starts the clock ticking on how long you have to attempt to repair the issue. In Pennsylvania, if you fail emissions, you have 30 days to show proof of X amount of dollars spent trying to fix the issue as shown with receipts for parts and labor etc. You can do the work yourself but you must save the receipts.

The difference between intentionally failing and being overdue is that intentionally failing technically means you cannot be fined for an overdue emissions inspection because you had one. I know New York is getting tighter on emissions. You of course also have the opportunity to take the car off the road until you are code and CEL free and then just don't get caught driving to the inspection station.

I don't have any ion PCM schematics but I will try to dig some up on the internet so that we can see where the wires from the sender in the tank lead to in order to tell The PCM how much fuel is in the tank.

Obviously, we can try to diagnose the actual problem at the same time which may or may not be more work. If you don't employ the workaround when you first go to inspection, if you do it to correct the code you won't have any receipts for parts purchased or work done to correct the issue so you need to think things through from beginning to end before you decide what to do.

My suggested workaround is a guess. An educated guess. I can't possibly say for sure whether it will work.