Hey guys, ive searched all over for the answer to this question but i havnt found someone with the same issue some similar issues but not the same. When my car is off, my tail lights stay on but they are not as bright as when you press the brake, pressing the brake makes them brighter. The only way to shut them off is to disconnect the battery/ open the car door (when the car door is open, the tail lights shut off.i checked the little rubber stoppers on the brake pedal to see if it was the brake switch not being pushed in. I took out the brake switch and pushed it in with my finger as much as it will go. they flickered off at one point but immediately came back on. i have checked the fuse box next to the battery and even when i pull out the tail lamp fuse the lights stay on. Does this mean its a relay issue.

also to note: my blinkers work, however my hazards will not. also my slip, vdc off and abs lights are now on. (it did now the other day and ik if its wet they will come on but now the come on right when you start the car.

any help/suggestions would be great!

 

Just to verify it's ONLY the taillight parking lamps that are on correct? None of the front parking lights are on? When you turn the headlights on is there any change with the tail lights? If there is NO CHANGE then you probably have broken wires in the trunk loom that are shorting out to other circuits.

If it's all the parking lights then I'm guessing you have moisture/water contamination in the IPDM. Remove it completely, including removing every fuse and relay, separate the case and see if there's moisture in it. If so take everything and let it sit in a bag of rice for 24 hours just like what you would do with a phone if you dropped it in the water.

Then clean the cowl drains which usually get plugged and causes the water to drain onto the IPDM.

If it's NOT wet inside the IPDM then check the BCM for any water in that location, usually you can feel around on the carpet to see if any water is leaking onto it.

 

Still need to get an OBD2 scanner on it and see why the slip, VDC lights are on, typically it's low brake fluid so I would check that first. This could be two unrelated problems.

 

Correct it is only the parking taillight lamps but not the bright brake lights. Also first thing I checked about that box light was the brake fluid and power steering and coolant levels. Thanks for the advice tho I’ll for sure check the wire and see if there’s any moisture.

 

Is the license place light also on when the vehicle is turned off?

Just to verify the front parking lights and front side indicators are NOT ON correct?

Hazard light switch is fairly easy to troubleshoot, it isn't a POWER circuit it's actually a switch that goes to GROUND and when the BCM sees ground it begins to flash all 4 turn signals. Get down to the switch, use a digital multimeter to verify the switch actually closes, make sure the second wire coming out of it reads zero resistance to the vehicle chassis. There should also be a light on the hazard switch when you turn the headlights on. If there is no illumination someone probably just forgot to plug it in when they were putting the console back together.

 

Front and side parking lights are not on and unfortunately I snapped the wire to my license plate light a while back so I’m unable to tell for that

 

Start by fixing the license plate light so you don't have a random hot wiring just hanging out at the rear of your car.

 

Update: the rear spoiler brake light is also on, leading me to believe it’s the brake lights. I replaced the brake switch with no results. Also what’s confusing me is why they all shut off when I open my door. Any ideas?

 

something is wet
IPDM? ECM?
Don't just start throwing parts without finding the root cause of your electrical problem.

Have you consulted the FSM?
Do you have a digital multimeter?

http://www.nicoclub.com/FSM/G35/Coup...Coupe/bcs.pdf#[0,{%22name%22:%22FitH%22},821]

SYSTEMS CONTROLLED BY BCM AND IPDM E/RSYSTEMS CONTROLLED BY BCM AND COMBINATION METERSYSTEMS CONTROLLED BY BCM AND INTELLIGENT KEY UNITSystemReferencePower door lockBL-21, "POWER DOOR LOCK SYSTEM"Remote keyless entryBL-50, "REMOTE KEYLESS ENTRY SYSTEM"Power window NOTEGW-17, "POWER WINDOW SYSTEM"Front power seat NOTESE-84, "POWER SEAT"Sunroof NOTERF-10, "SUNROOF"Room lamp timerLT-127, "INTERIOR ROOM LAMP"SystemReferencePanic alarmBL-50, "REMOTE KEYLESS ENTRY SYSTEM"Theft warningBL-188, "VEHICLE SECURITY (THEFT WARNING) SYSTEM"IVIS (NATS)BL-214, "IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS)"HeadlampLT-5 , "HEADLAMP - XENON TYPE -"Daytime light systemLT-3 5, "DAYTIME LIGHT SYSTEM"Auto light systemLT-5 1, "AUTO LIGHT SYSTEM"
Parking, license plate, side marker and tail lamps
Battery saver controlLT-109, "PARKING, LICENSE PLATE AND TAIL LAMPS"Front fog lampLT-6 4, "FRONT FOG LAMP"Front wiperWW-4, "FRONT WIPER AND WASHER SYSTEM"Rear window defoggerGW-58, "REAR WINDOW DEFOGGER"

https://www.nicoclub.com/FSM/G35/Cou...5_Coupe/lt.pdf

System DescriptionNKS002P7The control of the parking, license plate, side marker and tail lamp operation is dependent upon the position oflighting switch. When the lighting switch is placed in the 1ST position, 2ND position or AUTO position (head-lamp is ON), the BCM (body control module) receives input signal requesting the parking, license plate, sidemarker and tail lamps to illuminate. This input signal is communicated to the IPDM E/R (intelligent power distri-bution module engine room) through the CAN communication lines. The CPU (central processing unit) locatedin the IPDM E/R controls the tail lamp relay. This relay, when energized, directs power to parking, licenseplate, side marker and tail lamps, which then illuminate. Power is supplied at all times
through 10A fuse (No. 71, located in IPDM E/R)
to CPU located in IPDM E/R, and
to tail lamp relay, located in IPDM E/R,
through 15A fuse (No. 78, located in IPDM E/R)
to CPU located in IPDM E/R,
through 50A fusible link (letter F, located in fuse, fusible link and relay box)
to BCM terminal 55,
through 10A fuse [No. 18, located in fuse block (J/B)]
to BCM terminal 42.With the ignition switch in the ON or START position, power is supplied
to CPU located in IPDM E/R, from battery direct,
through 10A fuse [No. 1, located in fuse block (J/B)]

PARKING, LICENSE PLATE AND TAIL LAMPSRevision: 2006 August2007 G35 Coupe
to BCM terminal 38.With the ignition switch in the ACC or ON position, power is supplied
through 10A fuse [No. 6, located in fuse block (J/B)]
to BCM terminal 11.Ground is supplied
to BCM terminal 52
through grounds M30 and M66,
to IPDM E/R terminals 38 and 60
through grounds E17 and E43.OPERATION BY LIGHTING SWITCHWith the lighting switch in the 1ST position, 2ND position or AUTO position (headlamp is ON), the BCMreceives input signal requesting parking, license plate, side marker and tail lamps to illuminate. This input sig-nal is communicated to the IPDM E/R through CAN communication lines. The CPU located in the IPDM E/Rcontrols tail lamp relay, which when energized, directs power
through IPDM E/R terminal 22
to front side marker lamp RH and LH terminals 1
to front combination lamp RH and LH terminals 7
to rear combination lamp RH and LH terminals 3, and
to license plate lamp RH and LH terminals 1.Ground is supplied
to front side marker lamp RH and LH terminals 2, and
to front combination lamp RH and LH terminals 8
through grounds E17 and E43,
to rear combination lamp RH and LH terminals 4
through ground B103,
to license plate lamp RH and LH terminals 2
through grounds B5 and B29.With power and ground supplied, parking, license plate, side marker and tail lamps illuminate.

 

Just throwing this out there.
But check that the rubber pad on the brake pedal is in place (not missing) and/or not punctured.
You can hit the too brakes hard and sometimes push the pad right out. That is its function, to protect the brake switch from being destroyed.
It is the pad on the brake pedal that the brake switch plunger presses against/through.

If it is missing you can get another or just replace it with a 9mm body push pin..others have JB welded a nickel in that spot..some have used bolts in that spot, but I found them to be too thick to work with the switch properly.

If you use something solid as a stop, rather than the oem rubber plunger, you are going to destroy the brake switch when you jam on the brakes, as they will not give and push out when you jam on the brakes. Jamming on the brakes does you nothing anyway...
I decided to use the push pin anyway.

oem pn 46584-5P010
https://www.z1motorsports.com/brake-...r-p-15166.html

brake switch pad issue
https://g35driver.com/forums/g35-cou...itch-help.html

brake switch adjust
https://g35driver.com/forums/g35-cou...oving-car.html

 

So yes the first thing I did was check the rubber pads. Both there for both switches. I spent all night last night testing different things and I just can’t find it. I took apart the entire ipdm no water or corrosion that’s visible. Checked the trunk loom for loose wires all connected and look good. I saw a relay in the trunk not sure if it was for the tail lights but tried that. Pulled all fuses and relays for all 3 fuse boxes. I pulled the bcm fuse and it went off but I’m assuming it’s because the bcm controls like everything. I’m really just at a loss here. I did read something ab a stop light relay but couldn’t find a location for it. Since my door turns the lights off just by opening it I checked the door switch and it looked good the screw was properly grounding it. Checked for other lose grounds. I got my clutch replaced and my starter about 2 weeks ago. Is it possible there’s a ground around that area that they might not have secured? You guys have been very helpful tho any more ideas would be great.

 

ok..but just check that the pad is not punctured...it is just a hollow pad ..like a membrane over a grommet...and can appear to look intact.

I haven't had to track anything electrical down on the G35. Ive only repaired the center brake lights.

If you dont have a haynes manual, you should get one. Also download the free service manual.

 

I did check the pad. And to make sure it wasn’t the pad/switch I replaced the switch and then pushed it in all the way with a pen and the lights were still on.

 

If it had anything to do with a malfunctioning switch or the rubber circle, the lights would not shut off when you open the door

 

Then you should see a constant 12v at both or all three brake light may be the pnk/blu wires.
Either at the brake switch or at the lights..a 12v that will not go away with the brake switch position.

If the signal is constant despite the brake switch setting, I would disconnect (cut) the output pink/blu from the brake switch to see whether the lights stay on.

If the brake lights stay on after the disconnect from the switch output, there is a power short on the pnk/blu brake light power and you continue from there.

I don't see the BCM being involved with the brake lights...only the turn signals and hazards.