[Nfamous_SRT]

2018 Hellcat Charger 56k miles

Has anyone experienced a bad or failing IBS? I’ve been dealing with low voltage gremlin from hell for about 2.5mo now. So far I’ve replaced the alternator and the battery.. no change, I have had all the grounds checked.. ✅ I’ve had all the recent after market wiring checked ✅ 95% of the aftermarket wiring is 3+yrs old on the car.. so I’m fairly certain they aren’t related to the issue.

 

[Blickie]

2018 Hellcat Charger 56k miles

Has anyone experienced a bad or failing IBS? I’ve been dealing with low voltage gremlin from hell for about 2.5mo now. So far I’ve replaced the alternator and the battery.. no change, I have had all the grounds checked.. ✅ I’ve had all the recent after market wiring checked ✅ 95% of the aftermarket wiring is 3+yrs old on the car.. so I’m fairly certain they aren’t related to the issue.

View attachment 605569

The IBS is a sensor and does not control Voltage and Amperage outputs. The PCM controls Volts, thus Amps, based on the difference between Battery Voltage and System Load... it's called Electromotive Force (EMF) versus Counter Electromotive Force (Counter EMF). Voltage always pushes Amperage.

Go to the Performance Pages/After Run Cooler. What does the Battery Status say?

Who's alternator, new or rebuilt?

Who's battery & model?

What aftermarket wiring are you talking about specifically?

1. Do you have a separate Voltmeter? If so, attach to the battery terminals under the hood at the passenger front and situate it so you can see the meter from the driver's seat.

2. Start the engine.

3. Bring up the Voltmeter on the Performance Page.

4. Raise the engine RPM to at least 1,500 to 2,000 & hold.

5. Turn on everything possible... headlights on highbeam, A/C on Max, Fan on High, both front & rear defrosters. Do this for 2 minutes.

6. What is the voltage readings on both? Do the readings compare and are they steady and consistent?

 

[Nfamous_SRT]

battery status says 13.5 +/- (I assume that’s that’s you’re asking) tends to throw the batter indicator light with heavy throttle not always but usually.

I bought a brand new factory alternator installed at the dealer and the battery is also the OEM factory battery purchased Friday.

the aftermarket wiring I mentioned is a dash cam and independent battery wired to recharge while engine is running. I have some custom headlight lighting, a radar that’s taped into the rear view mirror for power and a battery tender thats attached to the engine bay terminals.

the reason I’m asking about the IBS is became my cars issues match what I read about the symptoms of a failing IBS the only symptom I’m not seeing is engine pulsing.

I will try to the voltage meter suggestion you provided.

 

[Blickie]

battery status says 13.5 +/- (I assume that’s that’s you’re asking) tends to throw the batter indicator light with heavy throttle not always but usually.

I bought a brand new factory alternator installed at the dealer and the battery is also the OEM factory battery purchased Friday.

the aftermarket wiring I mentioned is a dash cam and independent battery wired to recharge while engine is running. I have some custom headlight lighting, a radar that’s taped into the rear view mirror for power and a battery tender thats attached to the engine bay terminals.

the reason I’m asking about the IBS is became my cars issues match what I read about the symptoms of a failing IBS the only symptom I’m not seeing is engine pulsing.

I will try to the voltage meter suggestion you provided.

System Voltage output should be a minimum of 13.8 or .9 in warm weather, closer to 14.0. If the ambient temps are under 70, then you should see voltage at 14.0 or .1 or .2. Suggest temporarily disconnecting all of your add-ons, radar detector, battery tender & custom headlights and see what happens. They could be causing a short (internal short) and thus a draw/drain.

There are some other threads where custom lights emit a very strong magnetic field that interferes with other systems. Not a joke!

 

[Nfamous_SRT]

System Voltage output should be a minimum of 13.8 or .9 in warm weather, closer to 14.0. If the ambient temps are under 70, then you should see voltage at 14.0 or .1 or .2. Suggest temporarily disconnecting all of your add-ons, radar detector, battery tender & custom headlights and see what happens. They could be causing a short (internal short) and thus a draw/drain.

There are some other threads where custom lights emit a very strong magnetic field that interferes with other systems. Not a joke!

I’ve tried disconnecting everything already, made no difference.

its nowhere near 14.. when I initially make a change.. for example disconnecting aftermarket items or even when I replaced the alternator it would initially maintain 14.0 once I shut off the car and restart it, it would usually be mid 13 and slowly drop or slowly increase to 14.0 and then slowly drop to mid 12 eventually if I drove it long enough.
Is there any possibility it could be a the IBS? My car is tuned, so I’m trying to explore every possibility before replacing the PCM to fix the voltage regulator.

 

[Blickie]

I’ve tried disconnecting everything already, made no difference.

its nowhere near 14.. when I initially make a change.. for example disconnecting aftermarket items or even when I replaced the alternator it would initially maintain 14.0 once I shut off the car and restart it, it would usually be mid 13 and slowly drop or slowly increase to 14.0 and then slowly drop to mid 12 eventually if I drove it long enough.
Is there any possibility it could be a the IBS? My car is tuned, so I’m trying to explore every possibility before replacing the PCM to fix the voltage regulator.

Yeah, I think you're heading to the PCM...

Consider going back to Factory...

 

[Nfamous_SRT]

Yeah, I think you're heading to the PCM...

Consider going back to Factory...

I’m not going back to factory.. I’ll just have to buy new pcm.. but like I said I’m going to explore all possibilities before doing that.

how difficult would it be for the dealership to determine if it’s a bad pcm/voltage regulator? My fear is that they wont put any real effort into it because of the modification I’ve made. This has been my experience in the past with simple issues.

 

[Blickie]

I’m not going back to factory.. I’ll just have to buy new pcm.. but like I said I’m going to explore all possibilities before doing that.

how difficult would it be for the dealership to determine if it’s a bad pcm/voltage regulator? My fear is that they wont put any real effort into it because of the modification I’ve made. This has been my experience in the past with simple issues.

Don't believe the dealership has the ability to check parts of the firmware to see if it's working or intact, but they can tell if the PCM has been tampered.

The dealership should plug into your car and they'll see a hard code 1400 which means he PCM has been modified. At that point, they may refuse to help and they'll note and may void you warranty.

Suspect the tune has trashed parts of the PCM Code and thus your problems and a 1400 Code is set.

Best!

 

[Nfamous_SRT]

Don't believe the dealership has the ability to check parts of the firmware to see if it's working or intact, but they can tell if the PCM has been tampered.

The dealership should plug into your car and they'll see a hard code 1400 which means he PCM has been modified. At that point, they may refuse to help and they'll note and may void you warranty.

Suspect the tune has trashed parts of the PCM Code and thus your problems and a 1400 Code is set.

Best!

My warranty is long gone. I’m not worried about them knowing if my pcm has been tampered with. I just need to know if my PCM is bad before I spend $2000 to replace and reprogram.

 

[Blickie]

My warranty is long gone. I’m not worried about them knowing if my pcm has been tampered with. I just need to know if my PCM is bad before I spend $2000 to replace and reprogram.

If there are no PCM Codes stored, the best way to know is flash your PCM with a factory fresh certified image and then test. You'll know real quick. Other than that, it a guess.

 

[Unholy707]

Trade it in

 

[Bobo]

Trade it in

This is WHY I bought mine new and would never buy a used HC!!

 

[baabootoo]

Unless..................you buy a warranty WITH the used one.

 

[Bobo]

Unless..................you buy a warranty WITH the used one.

Too easy for the warranty provider to skeeze their way out of payin!

 

[juanagofast]

Don't believe the dealership has the ability to check parts of the firmware to see if it's working or intact, but they can tell if the PCM has been tampered.

The dealership should plug into your car and they'll see a hard code 1400 which means he PCM has been modified. At that point, they may refuse to help and they'll note and may void you warranty.

Suspect the tune has trashed parts of the PCM Code and thus your problems and a 1400 Code is set.

Best!

Didn't think a tune would mess with the pcm like that...

 

[Xylander]

In my experience, I've had Dodge flat out refuse to work on a car of mine that had a swapped PCM. I too was having voltage issues (2018 modified T/A 392) with an unlocked PCM. I took it in for a diagnostic and they said that since I had an aftermarket PCM, they didn't want to waste time chasing gremilns on an aftermarket setup and sent me down the road. Luckily, it turns out it was just the positive connection on the underhood junction box. I noticed a day or two later that when I'd hit a bump, the volts would fluctuate, so I knew then that it was a loose connection somewhere.