Boomer343
New member
- Joined
- Oct 21, 2019
- Messages
- 4
- Reaction score
- 0
- Points
- 1
- Genesis Model Type
- 2G Genesis Sedan (2015-2016)
I have posted previously about changing the Alternator to try and solve charging issues. The alternator, new Hyundai unit, didn't solve the issues.
Bought the car in 2017 with 36000 Km and it now has 61000 Km which means it doesn't see many long trips. Have a Noco 10 amp charger wired in and know that battery drain is going to happen so every 10 days to 2 weeks the charger would get put on overnight or longer.
When the voltage was checked with the car running it was always above 14 volts but then we would get the gps and radio reset along with harder shifts during some trips.
I came across a Blue Tooth battery monitor that wires across the terminals and installed it. Under $40 for it so not much to lose. Voltage showed steady output for a few weeks while driving. Then one day after starting the voltage kept dropping then climbed to 12.4 V and remained there while driving. Interestingly turning on the lights caused an immediate jump in charging voltage to above 14. Turning off the lights sometimes caused the charging voltage to drop back to 12.4 V or it may remain at the 14 plus volts. Temporary fix has been to drive with the lights on. It seems though that while the voltage is in range the current output isn't and the battery after driving settles at 12.7 to 12.74 Volts then declines slowly due to the continuing electrical draw of the electronics.
I replaced the positive battery terminal box and no change. When the car was parked for 2 months the battery was removed and showed no loss of charge over that time.
The car was taken to the dealer but it was charging that day so while various items were checked no fix was apparent to them.
I then started doing some in depth reading of the factory repair manual and decided to replace the Battery Temperature Sensor cable. There is an updated version available. I bought it directly from a seller in Korea, arrived in 7 days in a Hyundai parts box. sparekorea.com is their website.
I followed the manual and allowed the sensor to calibrate for 4 hours. Wow. So this is how it should charge. The output is very active, spiking when slowing down, reducing when the car is accelerating and not flat lining. Took a 30 minute drive and had hopes the sensor was the cure. No luck. After sitting for 3 hours the charging went back to flat lining at 14 plus volts. It was consistent for days with no need to turn on the headlights.
I decided to go through the various connections and treat them with a contact enhancer called Stabilant 22A. I removed the temperature sensor from the battery and did the ECM along with any other connectors I could access. BTW over the years I have cleaned all and any ground points and treated them with the Stabilant 22A.
Reattached the Battery Sensor cable and was happy to see active charging happening. Went for a short drive, stopped the car and 10 minutes later restarted .... flat line at 14 plus volts.
I decided to get a one car/one month subscription from All Data for $20 so I could access wiring diagrams. I spent more than a few hours working my way through first finding then deciphering data.
Here is what I have come up with. The Battery Sensor sends data on the battery and the wire that does that goes from the battery to a connector that is behind the kick panel, passenger side and from there to the ECM. It is not part of the larger data system. The ECM uses that information to then control the alternator output signal. The Alternator receives the information and sends information back. There is a regulator in the alternator as well. The dash panel has a monitoring circuit that has never shown any issues with the charging system by illuminating. It is on at start up.
I went through every schematic for the ECM. A nineteen page printout. Third last item is about the wire that comes from the headlight relay to the ECM giving giving notification of voltage demand for the headlights. A small ah ha moment and explanation of why the system would start charging in some manner when the light were turned on.
So at this point I believe the ECM is the faulty part and needs replacement. This requires that the replacement ECM is matched to the system and keys.
If you have made it this far and have any other insights, questions, suggestions I would be happy to hear them.
Bought the car in 2017 with 36000 Km and it now has 61000 Km which means it doesn't see many long trips. Have a Noco 10 amp charger wired in and know that battery drain is going to happen so every 10 days to 2 weeks the charger would get put on overnight or longer.
When the voltage was checked with the car running it was always above 14 volts but then we would get the gps and radio reset along with harder shifts during some trips.
I came across a Blue Tooth battery monitor that wires across the terminals and installed it. Under $40 for it so not much to lose. Voltage showed steady output for a few weeks while driving. Then one day after starting the voltage kept dropping then climbed to 12.4 V and remained there while driving. Interestingly turning on the lights caused an immediate jump in charging voltage to above 14. Turning off the lights sometimes caused the charging voltage to drop back to 12.4 V or it may remain at the 14 plus volts. Temporary fix has been to drive with the lights on. It seems though that while the voltage is in range the current output isn't and the battery after driving settles at 12.7 to 12.74 Volts then declines slowly due to the continuing electrical draw of the electronics.
I replaced the positive battery terminal box and no change. When the car was parked for 2 months the battery was removed and showed no loss of charge over that time.
The car was taken to the dealer but it was charging that day so while various items were checked no fix was apparent to them.
I then started doing some in depth reading of the factory repair manual and decided to replace the Battery Temperature Sensor cable. There is an updated version available. I bought it directly from a seller in Korea, arrived in 7 days in a Hyundai parts box. sparekorea.com is their website.
I followed the manual and allowed the sensor to calibrate for 4 hours. Wow. So this is how it should charge. The output is very active, spiking when slowing down, reducing when the car is accelerating and not flat lining. Took a 30 minute drive and had hopes the sensor was the cure. No luck. After sitting for 3 hours the charging went back to flat lining at 14 plus volts. It was consistent for days with no need to turn on the headlights.
I decided to go through the various connections and treat them with a contact enhancer called Stabilant 22A. I removed the temperature sensor from the battery and did the ECM along with any other connectors I could access. BTW over the years I have cleaned all and any ground points and treated them with the Stabilant 22A.
Reattached the Battery Sensor cable and was happy to see active charging happening. Went for a short drive, stopped the car and 10 minutes later restarted .... flat line at 14 plus volts.
I decided to get a one car/one month subscription from All Data for $20 so I could access wiring diagrams. I spent more than a few hours working my way through first finding then deciphering data.
Here is what I have come up with. The Battery Sensor sends data on the battery and the wire that does that goes from the battery to a connector that is behind the kick panel, passenger side and from there to the ECM. It is not part of the larger data system. The ECM uses that information to then control the alternator output signal. The Alternator receives the information and sends information back. There is a regulator in the alternator as well. The dash panel has a monitoring circuit that has never shown any issues with the charging system by illuminating. It is on at start up.
I went through every schematic for the ECM. A nineteen page printout. Third last item is about the wire that comes from the headlight relay to the ECM giving giving notification of voltage demand for the headlights. A small ah ha moment and explanation of why the system would start charging in some manner when the light were turned on.
So at this point I believe the ECM is the faulty part and needs replacement. This requires that the replacement ECM is matched to the system and keys.
If you have made it this far and have any other insights, questions, suggestions I would be happy to hear them.
