Strange Rear door puddle light problem.
Strange Rear door puddle light problem.
First of let me tell you i searched and i found a thread about this issue but no solution was found. I swaped out interior leds on wifes gs, dome light, door puddle lights, and the rear lights by the coat hooks. Everything went smooth and i had no problems i till i got to the pass side rear, which blinked when i put led in it and then stoped working completly. I tried swaping to stock bulb same thing all other doors work perfect.
After messing with it for a while i noticed the door ajar light dosent come on when you open the rear door, nor does the dome light or key hole light.....BUT the light above the rear door does come on...
I used a scope and found that with door open i get 12v out of the positive but no ground out of the negative so when i give it ground the light comes on...when i close the door and manualy give it ground the light stays on..
My only guess is the small light up top and the puddle light in the door on the same side run off a different cercuit? I guess thats possible, all i know is the light worked before and now it dosent....If the Latch was bad would that mean neither lgiths should turn on?
After messing with it for a while i noticed the door ajar light dosent come on when you open the rear door, nor does the dome light or key hole light.....BUT the light above the rear door does come on...
I used a scope and found that with door open i get 12v out of the positive but no ground out of the negative so when i give it ground the light comes on...when i close the door and manualy give it ground the light stays on..My only guess is the small light up top and the puddle light in the door on the same side run off a different cercuit? I guess thats possible, all i know is the light worked before and now it dosent....If the Latch was bad would that mean neither lgiths should turn on?
check to see if the switch for the door doesn't have any corrosion on it ..the switch is a open switch when the door is close and when you open it closes to make connection... clean it out with some contact cleaner and give a try( dont forget to disconnected the battery before spraying) i hope that help giving the info you give me...
this happen to me to and believe it or not some how the plug came out. so i pried the bottom of the door panal open and saw it was not plugged in so i replugged it and wha-la. look at the conection first is all i am sayin. gl
i dont think thats my problem though because at the connector where it connects to the bulb housing i have power at one wire but no ground.
Pole Position
Joined: May 2007
Posts: 3,405
Likes: 55
From: 408 NOR CAL
The Courtesy (door) Switch is hooked up to the Door ECU. The Door ECU commands the Door Courtesy Light and the Rear Interior (reading) Light to turn on and off based on the Door Switch. It also send the Door Ajar signal to the Body ECU which then turns on the light in the dash.
If the Interior light is working then the switch should be working...except the door ajar light issue. Your problem is probably the Door ECU since it both alerts the Body ECU of the Door Ajar signal and turns on Door Courtesy Light.
It could also be a connection problem between the ECU and the Body ECU and the Courtesy light. It's pretty unlikely in my opinion that two wiring issues would appear at the same time.
Your best bet is probably to go straight to the Door ECU (in the door) and check for output at Pins 3-BLUE and 5-RED/WHITE with the door open. These go to the Door Courtesy Light.
IF the left and right rear Door ECU's are the same then you could also try swapping them. This would be a easy way to isolate the ECU as the issue since the Left ECU would correct the issue. I don't know for sure if they are the same. Call Lexus and see if they use the same Part# for both or look on the parts themselves before you do this.
And of course take my advise at your own risk.
If the Interior light is working then the switch should be working...except the door ajar light issue. Your problem is probably the Door ECU since it both alerts the Body ECU of the Door Ajar signal and turns on Door Courtesy Light.
It could also be a connection problem between the ECU and the Body ECU and the Courtesy light. It's pretty unlikely in my opinion that two wiring issues would appear at the same time.
Your best bet is probably to go straight to the Door ECU (in the door) and check for output at Pins 3-BLUE and 5-RED/WHITE with the door open. These go to the Door Courtesy Light.
IF the left and right rear Door ECU's are the same then you could also try swapping them. This would be a easy way to isolate the ECU as the issue since the Left ECU would correct the issue. I don't know for sure if they are the same. Call Lexus and see if they use the same Part# for both or look on the parts themselves before you do this.
And of course take my advise at your own risk.
Driver School Candidate
Joined: Mar 2011
Posts: 10
Likes: 2
From: West Virginia
same issue on my GS300 2001
same issue on my 2001 GS 300 - LEFT rear door only - I traced it out and came t the same conclusion - Door ECU - I'm too cheap to replace the ECU to fix a puddle light, so I wired the puddle light to the Ashtray illumination light wires - at least the puddle light is on any time the headlights are on. The puddle light is hidden when the door is closed, so it does not cause an interior lighting issue.
Anyone know the cost of a rear door ECU? new? used?
Anyone know the cost of a rear door ECU? new? used?
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The door ecu is also called a multiplex computer. The part number for the rear right door on a 98 GS300 is 89224-30010. The retails price from Sewell is 514.30 and CL discount is 308.58. I think I will just deal with the dead light for now
pm me.....i can probably get this for you used for a cheap price
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