Possible to disable a specific CEL code?

[cwilliamsws6]

Because of my custom high output alternator for car audio my car occasionally throws a CEL for "battery voltage malfunction" despite the fact that in reality everything is working fine, plus I've added a volt gauge so I can monitor everything in real-time myself.

I have access to multiple high-end OBD-2 scan tools (like the big tablet based type ones) through the career academy I go to, could I just disable the specific code my car keeps pulling so it doesn't light up for that anymore?

 

[Hall]

I think what you would need to do is change the allowable range of voltage. But I thought a high-output alternator puts out higher amperage, not voltage ?

 

[cwilliamsws6]

It's a higher amperage yes, 250 amps vs the stock alternator which was 105. My voltage usually is at 14.5 but for whatever reason the ECU doesn't like it. Lol

 

[Wolf359]

Depends on the manufacturer. Usually you need manufacturer specific equipment that can make changes to the system. Even something like that I doubt if the manufacturer would want the dealers/tech to be able to disable that type of function so it probably doesn't exist.

You probably need another battery in parallel or a battery with a higher CCA rating.

A high output alternator doesn't mean much if if the current draw is high and the car is at idle.

Or you need to turn down the volume, the whole block probably doesn't share the same taste in your music.

 

[cwilliamsws6]

I do have a higher CCA battery, I posted about it awhile back, I shoehorned in a group 24F

 

[Dave9]

Put a schottky diode in series on the (VCC?) wire where voltage is measured, but particularly not in series with the alternator-battery output which would waste too much power and make too much heat. This will drop roughly 0.2V and make it happy if it's just ~0.1V over the threshold.

I doubt a scan tool could alter the voltage threshold and don't think you really want to completely disable the battery voltage sensing feature as it can be useful if not important to let you know when there's a problem, especially too low a voltage and you're just about to be stranded if you don't get it parked somewhere better than the side of a road (or the middle of one).

 

[bdcardinal]

Yes you can, but none of your scan tools can do it. You need the PCM tuned via an aftermarket tuner to do it. Unfortunately the ones that would do this can get harder to find since the EPA is restricting their sales.

 

[mattd]

It probably doesn't like it because the voltage/amperage output doesn't match that of the duty cycle of the regulator.

 

[Nick1994]

Isn't that the point of these car audio capacitors?

 

[zzyzzx]

Is the CEL preventing you from passing emissions?

 

[daves66nova]

Maybe the car throws a CEL because it don't like your kind of music??? LOL just kidding..........

 

[el Nuke]

It's a higher amperage yes, 250 amps vs the stock alternator which was 105. My voltage usually is at 14.5 but for whatever reason the ECU doesn't like it. Lol

The CEL and associated DTC are meant to protect the vehicle in times of abnormal operation. Ignoring or disabling them is done at your car’s peril.

If the charging system is constantly showing 14.5v, and briefly exceeding it from the sounds of it, your battery is at risk of boiling the acid off due to overcharging. This is also when hydrogen gas is produced, so check and double-check the vent tube is hooked up, if it has one.

If it were mine, I’d pull the battery out and check the fluid level inside. Any cell with an exposed plate can be refilled, but the damage is likely already done. Start saving for a replacement battery.

 

[Thermo1223]

As was said you are forcing the Alt. to output more amperage than required by the ECU. It's going to throw a code because it can't adjust the voltage down to something it wants especially to save the battery. My truck does this all the time especially on a hot day to not overstress the battery.

Other than a tuner suppressing the CEL or modifying thresholds you are always going to have that CEL.

 

[D60]

I think the answer will ultimately depend on the make. Generally, it's absolutely possible. A good tuner should be able to do it on GMs and Fords and Jeeps -- they can delete nearly any code but as bdcardinal said there are those who aren't thrilled about the ability to delete kitty efficiency, EGR, regen, DEF codes etc.

Even Forscan and J-scan will let you adjust TPMS thresholds or disable (my preference), change tire size and gear ratios, keep fogs on with high beams, lock up the inner rear brake on tight turns in 4lo (to copy the new Bronco) etc etc blah blah -- ok some of that is the Tazer, not J-scan

I'm simply not familiar with what is out there for other makes due to lack of experience.

 

[Skippy722]

I think the answer will ultimately depend on the make. Generally, it's absolutely possible. A good tuner should be able to do it on GMs and Fords and Jeeps -- they can delete nearly any code but as bdcardinal said there are those who aren't thrilled about the ability to delete kitty efficiency, EGR, regen, DEF codes etc.

Even Forscan and J-scan will let you adjust TPMS thresholds or disable (my preference), change tire size and gear ratios, keep fogs on with high beams, lock up the inner rear brake on tight turns in 4lo (to copy the new Bronco) etc etc blah blah -- ok some of that is the Tazer, not J-scan

I'm simply not familiar with what is out there for other makes due to lack of experience.

AlfaOBD for Chrysler/Dodge/Jeep/Ram/Alfa/Fiat/Citroen/Lancia/Maserati/Peugeot/and the VW Routan. That’s a mouthful. I don’t think it allows you to disable codes from being thrown though.

 

[Donald]

Given that the requirements for OBDII and the CEL came from the EPA do you really think that they would allow people to disable a CEL or a specific code?