Change Instrument Panel Junction Box help needed
08-20-20, 04:57 AM
#1
Driver School Candidate
Thread Starter
Join Date: Aug 2020
Location: NY
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Change Instrument Panel Junction Box help needed
Hello,
I am experiencing an electric issues with the the central dash backlight lights not coming on at night on my 2002 ES300.
A mechanic diagnosed the issue and thinks it has to do with the Instrument Panel Junction Box that holds all the fuses to the the left of the steering wheel on the driver's side.
He recommended I replace the Instrument Panel Junction Box.
I got a working replacement part from junk yard and ready to swap it out myself.
The part in question is called Block Assembly Driver Side Junction Box or sometimes it is referred to as Body Ecu or Instrument Panel Junction Box. I am attaching the diagram illustrating the part. It is part 82730A highlighted in green.
The question is. Once I swap it out, will my keys/fob work with the new part or will I have to do any re-programming?
Will I need to reset the #4 and 13 pin with paper clip of immobilizer?
Will I need to reprogram anything at all or will everything just work with the new part?
Just need to know what to expect before I set out to do this job.
Any help and advice would be greatly appreciated.
I am experiencing an electric issues with the the central dash backlight lights not coming on at night on my 2002 ES300.
A mechanic diagnosed the issue and thinks it has to do with the Instrument Panel Junction Box that holds all the fuses to the the left of the steering wheel on the driver's side.
He recommended I replace the Instrument Panel Junction Box.
I got a working replacement part from junk yard and ready to swap it out myself.
The part in question is called Block Assembly Driver Side Junction Box or sometimes it is referred to as Body Ecu or Instrument Panel Junction Box. I am attaching the diagram illustrating the part. It is part 82730A highlighted in green.
The question is. Once I swap it out, will my keys/fob work with the new part or will I have to do any re-programming?
Will I need to reset the #4 and 13 pin with paper clip of immobilizer?
Will I need to reprogram anything at all or will everything just work with the new part?
Just need to know what to expect before I set out to do this job.
Any help and advice would be greatly appreciated.
08-21-20, 03:38 PM
#2
Pole Position
Hello,
Where did you find information about that fuse box being a Body ECU?
I may be wrong, but from my understanding it is just a fuse box with a bunch of wires inside. Your door control receiver is located on the passenger side C-Pillar, theft warning module is in the center under the dashboard, and immobilizer codes are stored in the ECU, located under the glove box on the passenger side.
If you will short pins 4 and 13 in OBD2 connector (in case of my 2000 Lexus ES300 those are pins TC and CG), you will enter a self-diagnostic mode that will give you malfunction codes if there are any. From my understanding, they are not used for any programming.
In short, if I am not mistaken, you don't need to worry about your keys failing to work with the new fuse box installed. That said, to be sure, you can test it with the car partially disassembled - make sure that at least one window is opened, in case if doors will get locked, and assemble only essential stuff, do not put everything back together before you will make sure that everything functions correctly. In worst case possible, even if there is something that will prevent the key from working, you can just put the old one back in.
Hope this helps and best of luck!
Where did you find information about that fuse box being a Body ECU?
I may be wrong, but from my understanding it is just a fuse box with a bunch of wires inside. Your door control receiver is located on the passenger side C-Pillar, theft warning module is in the center under the dashboard, and immobilizer codes are stored in the ECU, located under the glove box on the passenger side.
If you will short pins 4 and 13 in OBD2 connector (in case of my 2000 Lexus ES300 those are pins TC and CG), you will enter a self-diagnostic mode that will give you malfunction codes if there are any. From my understanding, they are not used for any programming.
In short, if I am not mistaken, you don't need to worry about your keys failing to work with the new fuse box installed. That said, to be sure, you can test it with the car partially disassembled - make sure that at least one window is opened, in case if doors will get locked, and assemble only essential stuff, do not put everything back together before you will make sure that everything functions correctly. In worst case possible, even if there is something that will prevent the key from working, you can just put the old one back in.
Hope this helps and best of luck!
08-22-20, 06:15 AM
#3
Driver School Candidate
Thread Starter
Join Date: Aug 2020
Location: NY
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Thanks so much for the reply.
I ended up swapping the Junction Box and unfortunately it didn't solve my electric problem.
The central dashboard lights are backlit during the day. Yet, once the night comes and the main headlights turn on, the whole main dashboard goes dark!
I can manually turn off the headlights at night, and that action turns the backlight back on the central dash. Yet, as soon as I turn the headlights back on, the dash goes black again.
I had a local mechanic diagnose the issue. He took out a lot of the items under the hood and tested all the voltages and ground and found absolutely no issues there.
He then told me that the next culprit is the malfunctioning Junction Box as it controls all of these actions.
Now I have changed out to a working Junction Box and this did absolutely nothing to solve the issue.
Any idea what else it could be causing this issue?
I ended up swapping the Junction Box and unfortunately it didn't solve my electric problem.
The central dashboard lights are backlit during the day. Yet, once the night comes and the main headlights turn on, the whole main dashboard goes dark!
I can manually turn off the headlights at night, and that action turns the backlight back on the central dash. Yet, as soon as I turn the headlights back on, the dash goes black again.
I had a local mechanic diagnose the issue. He took out a lot of the items under the hood and tested all the voltages and ground and found absolutely no issues there.
He then told me that the next culprit is the malfunctioning Junction Box as it controls all of these actions.
Now I have changed out to a working Junction Box and this did absolutely nothing to solve the issue.
Any idea what else it could be causing this issue?
08-22-20, 09:54 AM
#4
Pole Position
Did you try adjusting a dimmer switch to the left of the steering? You should at least see instrument cluster changing brightness. If not, check the dimmer.
Did you check the Headlight switch? From my understanding, when the headlight switch is in the DLR OFF position, you should not see any lights turned on, both inside and outside. When the switch is turned to TAIL position (between AUTO and Headlight), you should see taillights, running lights and interior lights come on. When the switch is turned to Headlight position, you should see lights both in front and back of the vehicle. If that's not the case, check the Headlight switch.
Hope this helps and best of luck!
Did you check the Headlight switch? From my understanding, when the headlight switch is in the DLR OFF position, you should not see any lights turned on, both inside and outside. When the switch is turned to TAIL position (between AUTO and Headlight), you should see taillights, running lights and interior lights come on. When the switch is turned to Headlight position, you should see lights both in front and back of the vehicle. If that's not the case, check the Headlight switch.
Hope this helps and best of luck!
08-22-20, 03:54 PM
#5
Driver School Candidate
Thread Starter
Join Date: Aug 2020
Location: NY
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Did you check the Headlight switch? From my understanding, when the headlight switch is in the DLR OFF position, you should not see any lights turned on, both inside and outside.
In this position all the out light are OFF and all the inside lights are ON. When the switch is turned to TAIL position (between AUTO and Headlight), you should see taillights, running lights and interior lights come on.
In this position taillights, daytime running lights are ON and all the inside cluster lights are ON and middle console lights are OFF
The only way at night to get the centre console to light up is t turn the headlight switch to DLR off. Of course, that cuts off the main headlights, but in exchange lights up the central console (where radio, clock, and AC controls are).
Obviously I cannot do it, as I cannot drive without the headlights.
Any other thoughts?
In this position all the out light are OFF and all the inside lights are ON. When the switch is turned to TAIL position (between AUTO and Headlight), you should see taillights, running lights and interior lights come on.
In this position taillights, daytime running lights are ON and all the inside cluster lights are ON and middle console lights are OFF
The only way at night to get the centre console to light up is t turn the headlight switch to DLR off. Of course, that cuts off the main headlights, but in exchange lights up the central console (where radio, clock, and AC controls are).
Obviously I cannot do it, as I cannot drive without the headlights.
Any other thoughts?
08-23-20, 05:09 PM
#6
Pole Position
Sorry, but it is a bit difficult for me to say something about your particular situation, since my car is a 2000 ES300. My system is wired completely differently, so all I can do is point at the sky and hope that it will turn out to be the culprit..
Were there any modifications done to the car at all? Your case is really weird, since taillights are wired from the same relay as interior lights, so when those come on, your interior lights should also switch on. You replaced an entire fuse box, so the TAIL and Integration relays, as well as PANEL fuse can be thrown out. I doubt that it is a Body ECU either, since its task is to trigger TAIL relay, which is directly connected to taillights.
You can try checking the interior dimmer switch - check if it works at all, and if something changes if it is unplugged. The wiring also goes through the instrument cluster, so you can unplug it as well to see if something would change.. You can find a wiring diagram here (Illumination system is described at page 158 in the book). Just for kicks and giggles, try pulling PANEL fuse and/or TAIL relay out when the interior lights are on, that should turn them off.
Again, I am basically just grasping at straws, yet that is all I can think of right now..
Hope this helps and best of luck!
Were there any modifications done to the car at all? Your case is really weird, since taillights are wired from the same relay as interior lights, so when those come on, your interior lights should also switch on. You replaced an entire fuse box, so the TAIL and Integration relays, as well as PANEL fuse can be thrown out. I doubt that it is a Body ECU either, since its task is to trigger TAIL relay, which is directly connected to taillights.
You can try checking the interior dimmer switch - check if it works at all, and if something changes if it is unplugged. The wiring also goes through the instrument cluster, so you can unplug it as well to see if something would change.. You can find a wiring diagram here (Illumination system is described at page 158 in the book). Just for kicks and giggles, try pulling PANEL fuse and/or TAIL relay out when the interior lights are on, that should turn them off.
Again, I am basically just grasping at straws, yet that is all I can think of right now..
Hope this helps and best of luck!
Last edited by Arsenii; 08-23-20 at 05:12 PM.
12-02-22, 02:01 PM
#7
Did you check the Headlight switch? From my understanding, when the headlight switch is in the DLR OFF position, you should not see any lights turned on, both inside and outside.
In this position all the out light are OFF and all the inside lights are ON. When the switch is turned to TAIL position (between AUTO and Headlight), you should see taillights, running lights and interior lights come on.
In this position taillights, daytime running lights are ON and all the inside cluster lights are ON and middle console lights are OFF
The only way at night to get the centre console to light up is t turn the headlight switch to DLR off. Of course, that cuts off the main headlights, but in exchange lights up the central console (where radio, clock, and AC controls are).
Obviously I cannot do it, as I cannot drive without the headlights.
Any other thoughts?
In this position all the out light are OFF and all the inside lights are ON. When the switch is turned to TAIL position (between AUTO and Headlight), you should see taillights, running lights and interior lights come on.
In this position taillights, daytime running lights are ON and all the inside cluster lights are ON and middle console lights are OFF
The only way at night to get the centre console to light up is t turn the headlight switch to DLR off. Of course, that cuts off the main headlights, but in exchange lights up the central console (where radio, clock, and AC controls are).
Obviously I cannot do it, as I cannot drive without the headlights.
Any other thoughts?
Did you ever figure out the problem?
I just got a 04 ES330 and I'm having the same exact problem you having.
I've searched endlessly but there isn't much about this issue out there except this threat.
Anyone ... anything would be helpful.
Thx in advance.
Trending Topics
12-02-22, 09:21 PM
#8
Pole Position
As written above, I do not own a 4th-gen ES300/330, so I can only guess at the culprit. With that, so long as all the corner lights are working when you turn them on, there can only be one major culprit to this issue - the Body ECU. All the illumination lights in the center console are routed through and controlled by the Body ECU, which is located in the Fuse Box on the Driver's side, under the storage cover. While it is easy to find at the junkyard, the sheer amount of work to take it out is quite severe, so only try to replace it if you have plenty of spare time.
Hope this helps and best of luck!
Hope this helps and best of luck!
12-03-22, 05:22 PM
#9
As written above, I do not own a 4th-gen ES300/330, so I can only guess at the culprit. With that, so long as all the corner lights are working when you turn them on, there can only be one major culprit to this issue - the Body ECU. All the illumination lights in the center console are routed through and controlled by the Body ECU, which is located in the Fuse Box on the Driver's side, under the storage cover. While it is easy to find at the junkyard, the sheer amount of work to take it out is quite severe, so only try to replace it if you have plenty of spare time.
Hope this helps and best of luck!
Hope this helps and best of luck!
Thread
Thread Starter
Forum
Replies
Last Post