Three Hemi Error codes that just don't make sense - Help needed!

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MikoS

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I've only recently joined the wonderful world of Hemi's, and so this is my first post. I have a 2016 Hemi SLT which has 3 error codes that AlfaOBD picks up and I cannot get rid of. My concern is that they may all be caused by some common hidden problem and not actually be three separate problems.
I should mention that I bought it wrecked, and although the damage was slight, the seat and side curtain airbags had deployed. I replaced those and had the Airbag module reset by Safety Restore Inc. However the Airbag light does come on occasionally and AlfaOBD picks up the code B21DD - 'System Voltage below Threshold' See screenshot below. As I see it this is the entire airbag system that has low voltage? Not just any one single airbag problem...? This code cannot be cleared although the Airbag light itself is only on occasionally. Like once or twice per month max.

The second code is B16D7 - 'Left Taillamp 1 Control short circuit to + battery/open circuit' I have replaced the bulb and inspected the wiring harness but can find no breaks or damage. I can clear this code but it will come back within 30 miles or so.

The third code is P0111 - 'Intake Air Temp Sensor 1 Circuit performance' I have replaced this IAT sensor and also run bench tests and the ohm readings etc are spot on. I read that this error can be caused by an out of range difference between it and the coolant Temp sensor. So I checked out the coolant sensor and it too checks out fine on a bench test. I can clear this code but it will come back within 30 miles or so.

Apologies that I've written such a lot but I felt to put out all the problems in case they are connected in any way.
I'm hoping that one of you Hemi guru's can offer some advice!

Thanks in advance!
MikoS

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jws123

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Test battery check all grounds make sure alternator is putting out good voltage as well.
 

huntergreen

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If it’s a fault with the battery /alternator , funky things happen.
 
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MikoS

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Test battery check all grounds make sure alternator is putting out good voltage as well.
Yes, I am hoping it is something like that. The battery is new though. The voltage on the instrument panel shows 14v when running so I guess the alternator is good too... but I'll check it properly with the meter tonight in case. And the grounds too
 

tron67j

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Check your taillight wiring. I have seen people crimp in wires for backup cameras, lighting, etc. and that can cause problems when it starts to rust out over time.
 

RASelkirk

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If it’s a fault with the battery /alternator , funky things happen.
With my '98 Dakota R/T, I always got a warning that the battery was about to take a dump. Everything would behave normally. including startup, but the IAC motor would stick shut. Those couple times I had to drive home from work feathering the throttle so it wouldn't die in traffic.

Russ
 

PoMansRam

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Are there any aftermarket electronics on the vehicle? Any off brand LED replacement bulbs?
 

turkeybird56

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Yes, I am hoping it is something like that. The battery is new though. The voltage on the instrument panel shows 14v when running so I guess the alternator is good too... but I'll check it properly with the meter tonight in case. And the grounds too
Should be more than 14V on Battery, on panel. Should be 14.5 or 14.6 V being read. Use Volt/Multi Meter across battery terminals or positive and behind batt sensor on negative. Also shut down completely, turn all off, raise hood, close door. When all shuts down, check voltage across terminals, should be 12.4 to 12.6, NE thing under 12, battery starting to go. After that, check on the other recommendations above. With air bag going off and all, might be a crimped, pinched wire also.

ADDED: Make sure U use a multi-meter/volt meter to check and not rely on FCA lie-o-meters, LMAO. But I do find my interior Batt Voltage meter is usually pretty close, more or less. My Lie-O-Meter in the truck actually reads 2/10's (.2) lower than what I get on a Digital Multi-Meter, just FYI for all.
 
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MikoS

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Should be more than 14V on Battery, on panel. Should be 14.5 or 14.6 V being read. Use Volt/Multi Meter across battery terminals or positive and behind batt sensor on negative. Also shut down completely, turn all off, raise hood, close door. When all shuts down, check voltage across terminals, should be 12.4 to 12.6, NE thing under 12, battery starting to go. After that, check on the other recommendations above. With air bag going off and all, might be a crimped, pinched wire also.

ADDED: Make sure U use a multi-meter/volt meter to check and not rely on FCA lie-o-meters, LMAO. But I do find my interior Batt Voltage meter is usually pretty close, more or less.
Thanks for this. I'll get on to it as soon as I get a chance and update here. Unfortunately time is not my friend right now:(
 

Dusty

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"The third code is P0111 - 'Intake Air Temp Sensor 1 Circuit performance' I have replaced this IAT sensor and also run bench tests and the ohm readings etc are spot on. I read that this error can be caused by an out of range difference between it and the coolant Temp sensor. So I checked out the coolant sensor and it too checks out fine on a bench test. I can clear this code but it will come back within 30 miles or so."

Actually there are three set conditions:

The Powertrain Control Module (PCM) compares the Ambient Air Temperature (AAT), Engine Coolant Temperature (ECT), and Intake Air Temperature (IAT) Sensor values. If one sensor value is not within approximately 10°C (18°F) of the other temperature sensors for two consecutive trips, a DTC will set.

Possible causes are: IAT signal circuit high resistance, a sensor ground circuit high resistance, faulty IAT sensor, or PCM.

If you have access to a wiring diagram, check to see if all of the circuits dealing with B16DD, B21DD, and P0111 somewhere go through the same connector or utilize a common ground.

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 68277 miles
 
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MikoS

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Apologies for taking so long to update this post with the solutions to my problems.
The taillight short was as simple as replacing the taillight socket...! Many many hours wasted by thinking that it was a more serious problem! So we learn!
The problem with the air intake sensor was just as simple! Turns out that someone had fitted the wrong one in the past! It was way too short in physical length so even though it tested as good on the bench it was not giving the engine what it wanted! Stupid me first replaced it with an identical one (different year model?) before getting the correct Mopar...

I still have the airbag issue though. Although I did have my airbag module reset after the wreck, I still have the airbag light on. (B21DD System under voltage.) I did replace the deployed airbags but not any impact sensors. Is there a known resistance reading over the terminals of the impact sensors that would prove them good or bad...? Or how are they tested?
 
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Jim BB

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as far as the Air bag did you replace the clock spring or any of the sensors?
since we don't know where the damage or impact was on the truck ( you never said ) chances are you have a bad impact sensor ! it takes 2 sensors to make a air bag go off and 99% of the time depending on where th damage is you need to replace the sensors as well as the bags! and

(PLEASE NOT ALWAYS CHECK AIR BAG SYSTEM WITH DIGITAL METER)
 
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MikoS

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as far as the Air bag did you replace the clock spring or any of the sensors?
since we don't know where the damage or impact was on the truck ( you never said ) chances are you have a bad impact sensor ! it takes 2 sensors to make a air bag go off and 99% of the time depending on where th damage is you need to replace the sensors as well as the bags! and

(PLEASE NOT ALWAYS CHECK AIR BAG SYSTEM WITH DIGITAL METER)
Hi thanks for the reply. The impact was right front wheel and on the side of the bed just in front of right rear wheel. Both seat airbags and both roof curtain airbags were deployed and have been replaced. The steering wheel airbag did not deploy. I have measured the resistance on each of the 6 impact sensors (3 per side) and they all give a reading of about 25k/ohms one way across the terminals or 95 k/ohms if the polarity of the multimeter wires are reversed. I have tested an aftermarket sensor which gave 30 and 100k/ohms which is close enough I guess? So my question is this... what is a bad impact sensor? Would it give a zero reading across the terminals? or how is it tested? I'm quite happy to replace sensors but at this point I can find no indication of which is bad if any...
 

Jim BB

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Hi thanks for the reply. The impact was right front wheel and on the side of the bed just in front of right rear wheel. Both seat airbags and both roof curtain airbags were deployed and have been replaced. The steering wheel airbag did not deploy. I have measured the resistance on each of the 6 impact sensors (3 per side) and they all give a reading of about 25k/ohms one way across the terminals or 95 k/ohms if the polarity of the multimeter wires are reversed. I have tested an aftermarket sensor which gave 30 and 100k/ohms which is close enough I guess? So my question is this... what is a bad impact sensor? Would it give a zero reading across the terminals? or how is it tested? I'm quite happy to replace sensors but at this point I can find no indication of which is bad if any...

so the Passenger side dash bag did not go off correct!?
Airbag Control Module (ACM) located under the instrument panel, on the transmission hump have you had that checked lots of times they pooch out once fired .
I also just seen a video about the air bag light coming on the person in the video say's it is a common issue it is a connector under the seat he shows the drivers seat i do not know if passengers seat has same connector or not !
hope the file i loaded works Ram 1500 service airbag system easy fix - YouTube
maybe give that a try
at work I have a obd tester that does air bags do you access to a really good obd scan tool that does in-depth scans and test? that's the only other way I can think of to help you other than start to through good money at something that could be minor. I don't like just throwing parts and money at things unless i know for sure
sorry I can't be more of a help!
If you have any other question I may be able to help
 

Daw14

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Hi thanks for the reply. The impact was right front wheel and on the side of the bed just in front of right rear wheel. Both seat airbags and both roof curtain airbags were deployed and have been replaced. The steering wheel airbag did not deploy. I have measured the resistance on each of the 6 impact sensors (3 per side) and they all give a reading of about 25k/ohms one way across the terminals or 95 k/ohms if the polarity of the multimeter wires are reversed. I have tested an aftermarket sensor which gave 30 and 100k/ohms which is close enough I guess? So my question is this... what is a bad impact sensor? Would it give a zero reading across the terminals? or how is it tested? I'm quite happy to replace sensors but at this point I can find no indication of which is bad if any...
Have you given a thought as to taking it back to safety restore for them to have another look ?
 
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MikoS

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Have you given a thought as to taking it back to safety restore for them to have another look ?
Yes I have. The airbag module is currently getting reset once again. I'm trying someone else this time around though.
 
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MikoS

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so the Passenger side dash bag did not go off correct!?
Airbag Control Module (ACM) located under the instrument panel, on the transmission hump have you had that checked lots of times they pooch out once fired .
I also just seen a video about the air bag light coming on the person in the video say's it is a common issue it is a connector under the seat he shows the drivers seat i do not know if passengers seat has same connector or not !
hope the file i loaded works Ram 1500 service airbag system easy fix - YouTube
maybe give that a try
at work I have a obd tester that does air bags do you access to a really good obd scan tool that does in-depth scans and test? that's the only other way I can think of to help you other than start to through good money at something that could be minor. I don't like just throwing parts and money at things unless i know for sure
sorry I can't be more of a help!
If you have any other question I may be able to help
Correct. The passenger side bag didn't deploy.
:)I have seen that same video in all my many searches...:D but it wasn't that.
The airbag module is currently being reset for the 2nd time so if the light is still on after that then I'll give up and take it in somewhere with proper testing equipment.
 

Mister Luck

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There is a recall on the passenger side airbag for 2016
and I not sure if all 2016 used Takata’s but there is a notice on those as well.

The negative battery post clamp uses an integrated smart charging chip that communicates with the CAN buss and they can be damaged if not handled correctly if unknown history or service.

The tail lamp is probably a wonky ground.
 
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MikoS

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Ok so all my problems are sorted now. The third and last remaining problem was the Airbag codes. I had the Airbag module reset for the 2nd time with a different person but still with no change in results. The codes just were stuck there and were not clearable at all. In desperation I bought a used module from a guy who agreed that I could return it if it made no difference. I put it in and reset the Vin using AlfaOBD. Then I ran a code scan. A whole bunch of codes showed up (much more than with my own module) but Alfa OBD cleared every one of them away and they have not come back.:D

Thanks to all for the help and advice...!
 
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