magnum_rg

hi, on my g37 2008 sedan a monitor stays on after ignition is off, or even all doors are locked from outside. Sometimes it turns off as normal, but after 10-20 seconds turns on by itself. I have to disconnect the battery everytime. Any idea?

ILM-NC G37S

iTrader: (3)

When this happens and the car is shut off, what is shown on the display? In other words, does the AV system still function when the car is completely off?

magnum_rg

yes, when the car is completely off the system still function, no matter is it radio or disk, or audio is off, etc.

ILM-NC G37S

iTrader: (3)

The only physical way the AV system can stay ON (receive battery power) after you turn the car OFF is by the car going into ACC(essory) mode. This can be caused by a few things:
- ACC relay stuck "ON"
- START button fault
- wiring issue/corrosion
- water intrusion

Here are some things you can check:

- For one, when you turn the car OFF, what does the START button indicate? (OFF ACC or ON)?
-With your foot OFF the brake pedal, press the START button slowly- one press at a time- to make sure the car cycles from OFF --> ACC --> ON --> OFF, etc.
- Check the fuse boxes under the hood near the battery. You want to make sure there is no water intrusion or signs of wiring issues.
- You will also need to check the BCM area for any signs of water intrusion.

Take note, when you turn OFF your car, be sure you are only pressing the START button ONCE. Pressing TWICE will automatically shut the engine off but leave the car in ACC mode. Sometimes it is very easy to accidentally hit the button twice- possible but not probable.

Unfortunately, if the ACC relay is stuck, it can not be individually replaced as it is incorporated into the IPDM/er (fuse box next to battery) which can only be replaced as a whole.

llebcire

Along with the detailed reply from @ILM-NC G37S , have there been any modifications to your audio system?

Have you had this vehicle for very long? I ask as the previous owner could have modified something that's now having unintended consequences.
Have you modified anything? You've previously mentioned wanting to add an adapter (Kivic One) to mimic your Android device - have you made any changes to the stock audio/visual system?

-Eric

magnum_rg

llebcire, currently there is no any customization/connections on a/v system.

I also made an ecu diagnostics with obd scanner but no errors.

After some checks: when engine is off and screen is still on, all indicators on START button are disabled (OFF, ACC, ON). Sometimes a screen stays only for 3-4 seconds, and I noticed that in this period a yellow key indicator on dashboard is also is on. I tried with another key fob/new battery but no success.

Another issues:
1. seat memory buttons (1,2 and set) are not functioning - no lights, no reactions.
2. also there is a strange noise on saloon right after the engine is on, like lower tone whistling , but audio is completely is off

ILM-NC G37S

iTrader: (3)

OBD will not really help here unless you have access to a CONSULT 3 or advanced scanner. Still, never hurts to check.
This indicates that there is a potential problem with the car side of the i-key system (IVIS/NATS)- NOT necessarily a problem with the fobs themselves. A major fault here can leave you stranded.
Is this a UK-spec car? I ask only as our British friends usually refer to sedans as "saloons." Not that it really matters in this case, however.

Almost all of your issues- including the seat memory- all tie directly to the BCM in some way or other. When you turn the car OFF, the BCM tells the IPDM to shut off- which shuts down the engine and electronics (AV, meter, HVAC, etc.). The start button, IPDM, ECU, IVIS (NATS (i-key)) even the ADP (seat memory) are connected to the BCM.

Have you checked for water intrusion in/on/near the BCM? These cars are becoming more common to water intrusion either as a result of a failed sunroof drain grommet and/or the firewall grommet where the main wiring harness passes through from the battery.

Perhaps some other forum members might have some suggestions.

jmw416

Did you ever resolve this? My car just starting doing this today.

magnum_rg

yes, just open and clean all connectors in IPDM module